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1.	Adineh, Morteza, et al. (författare) Microstructure, mechanical properties and machinability of Cu-Zn-Mg and Cu-Zn-Sb brass alloys 2019 Ingår i: Materials Science and Technology. - : TAYLOR & FRANCIS LTD. - 0267-0836 .- 1743-2847. ; 35:12, s. 1504-1514 Tidskriftsartikel (refereegranskat)abstract Lead-free alloys have attracted great attentions recently due to the toxic nature of lead for the human body. In this study, low amounts of Mg and Sb were added to the Cu65-Zn35 brass and microstructure, mechanical properties and machinability of samples were compared to Cu65-Zn35 brass. Both Mg and Sb led to the promotion of beta ' phase as well as the formation of new ternary copper rich intermetallic particles. It was found that these particles had a significant role in the reduction of the ultimate tensile strength, toughness, work hardening and elongation while increasing the hardness of samples. Results of machinability evaluation of samples showed that the cutting forces were decreased significantly and morphology of chips were improved compared to Cu65-Zn35 brass sample.
2.	Andersson, Joel, 1981-, et al. (författare) Effect of Different Solution Heat Treatments on the Hot Ductility of Superalloys : Part 3 - Waspaloy 2013 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 29:1, s. 43-53 Tidskriftsartikel (refereegranskat)abstract The susceptibility to heat affected zone cracking of Waspaloy has been investigated in terms of its hot ductility, measured as the reduction of area (RA). Gleeble testing with on-heating as well as on-cooling test cycles was carried out to illuminate the influence of different 4 h solution heat treatments between 996 and 1080°C. A ductility maximum of between 80 and 90%RA was found at 1050–1100°C for all conditions in the on-heating tests. Although the different heat treatment conditions showed similar macrohardness, the particle size and distribution of the γ′ and M23C6 phases differed, which significantly affected the on-heating ductility in the lower temperature test region. The ductile to brittle transition was initiated at 1100°C in the on-heating testing with indications of grain boundary liquation at the higher test temperatures. Ductility recovery, as measured in the on-cooling tests from 1240°C, was very limited with <30%RA for all conditions and test temperatures except for the 1080°C/4 h treatment, which exhibited 60%RA at 980°C.
3.	Andersson, Joel, 1981-, et al. (författare) Effect of solution heat treatments on superalloys : Part 1 – alloy 718 2012 Ingår i: Materials Science and Technology. - : Taylor & Francis Group. - 0267-0836 .- 1743-2847. ; 28:5, s. 609-619 Tidskriftsartikel (refereegranskat)abstract The hot ductility as measured by Gleeble testing of Alloy 718 at four different solution heat treatments (954°C/15 h, 954°C/1 h, 982°C/1 h and 1050°C/3 h+954°C/1 h) has been investigated. It is concluded that constitutional liquation of NbC assisted by δ phase takes place and deteriorates the ductility. Parameters established by analysing the ductility dependence on temperature indicate a reduced weldability of the material in the coarse grain size state (ASTM 3) while indicating an increased weldability when containing a large amount of δ phase due to a grain boundary pinning effect. The accumulation of trace elements during grain growth at the highest temperature is believed to be the cause for the observed reduced on-cooling ductility.
4.	Andersson, Joel Håkan, 1981, et al. (författare) Effect of different solution heat treatments on hot ductility of superalloys Part 2-Allvac 718Plus 2012 Ingår i: Materials Science and Technology. - : Taylor & Francis Group. - 1743-2847 .- 0267-0836. ; 28:6, s. 733-741 Tidskriftsartikel (refereegranskat)abstract The hot ductility of Allvac 718Plus for different solution heat treatments (954 degrees C-15 h, 954 degrees C-1 h, 982 degrees C-1 h and 1050 degrees C-3 h+954 degrees C-1 h) has been investigated using Gleeble testing. Substantial variations in the microstructure among the heat treatments affected the Gleeble test hot ductility only to a very limited extent. Constitutional liquation of the NbC phase was found to be the main cause for the poor ductility at high testing temperatures in the on-heating cycle as well as at the lower temperatures on-cooling. Grain boundary delta phase was seen to assist the constitutional liquation of the NbC phase. Based on established evaluation criteria for Gleeble ductility testing, a ranked indicator for weldability is suggested.
5.	Andersson, Joel Håkan, 1981, et al. (författare) Effect of solution heat treatments on superalloys Part 1 - alloy 718 2012 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 1743-2847 .- 0267-0836. ; 28:5, s. 609-619 Tidskriftsartikel (refereegranskat)abstract The hot ductility as measured by Gleeble testing of Alloy 718 at four different solution heat treatments (954 degrees C/15 h, 954 degrees C/1 h, 982 degrees C/1 h and 1050 degrees C/3 h+954 degrees C/1 h) has been investigated. It is concluded that constitutional liquation of NbC assisted by delta phase takes place and deteriorates the ductility. Parameters established by analysing the ductility dependence on temperature indicate a reduced weldability of the material in the coarse grain size state (ASTM 3) while indicating an increased weldability when containing a large amount of delta phase due to a grain boundary pinning effect. The accumulation of trace elements during grain growth at the highest temperature is believed to be the cause for the observed reduced on-cooling ductility.
6.	Andersson-Östling, Henrik C.M., et al. (författare) Influence of phosphorus, sulphur and grain size on creep in pure copper 2009 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract Uniaxial creep tests have been performed at 175 °C to study the influence of phosphorus, sulphur and grain size on the creep properties of oxygen free copper. Copper with no phosphorous content and copper with 2000 μm grain size showed lower creep strength and ductility than the reference material which contained 58 ppm phosphorous and had 350 μm average grain size. Phosphorous content of 29 and 106 ppm showed no difference in relation to the reference material, and neither did grain sizes of 100 and 800 μm average grain size. 6 or 12 ppm sulphur did not affect the creep properties at all. The main creep rupture mechanisms were found to be cavitation and microcracking at the grain boundaries. The observed influence of P on creep is consistent to previously published models both with respect to creep rate and creep ductility.
7.	Andersson-Östling, Henrik C.M., et al. (författare) Testing and modelling of creep in copper friction stir welds 2009 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract Specimens cut from friction stir welds in copper canisters for nuclear waste have been used for creep experiments at 75°C. The specimens were taken from a cross-weld position as well as heat affected zone and weld metal. The weld specimens exhibited shorter creep lives than the parent metal specimens by a factor of three in time. The cross weld and HAZ specimens were shorter by an order of magnitude when compared to the weld metal. The creep exponent was in the interval 50 to 69 implying that the material was well inside the power-law breakdown regime. The ductility properties expressed as reduction in area were not significantly different in the weld zones and all the rupture specimens demonstrated valu esexceeding 80%. The stationary creep rate for the parent metal was consistent with a previously developed model. The primary creep was successfully modelled. Weld reduction factors have been obtained by comparing the results from base metal tests and weld tests. Measured values at 75 °C for are about 6% for friction stir welds and 14% for electron beam welds.
8.	Bakshi, S. Das, et al. (författare) Dry rolling/sliding wear of nanostructured pearlite 2015 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 31:14, s. 1735-1744 Tidskriftsartikel (refereegranskat)abstract The dry rolling-sliding wear behaviour of pearlite that has an interlamellar spacing of just 85 nm has been characterised. Its wear resistance is found to be comparable to that of much harder bainitic steels. Microstructural observations indicate that there is substantial plastic deformation of both ferrite and cementite components of pearlite in the vicinity of the wear surface. Plasticity is not expected from Hertzian analysis that assumes a smooth contact surface. Instead, it is likely to be a consequence of exaggerated stresses due to surface roughness. The material remains ductile to shear strains in the order of 4. Diffraction data indicate that the coherent domain size is reduced to about half the interlamellar spacing and that some of the cementite may dissolve and contribute to the expansion of the lattice parameter of ferrite
9.	Barbaro, F. J., et al. (författare) Formation of acicular ferrite at oxide particles in steels 1989 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 5:11, s. 1057-1068 Tidskriftsartikel (refereegranskat)abstract Experimental steels similar in composition to structural grades were prepared from weld metal deposits to study the formation of acicular ferrite under conditions experienced in the heat affected zone for a range of welding processes. The formation of acicular ferrite under these conditions is found to be dependent on the presence of a suitable distribution of oxide inclusions > 0·4 μm in size. The characteristics and proportion of acicular ferrite in the microstructure also depend on the prior austenite grain size and cooling rate. The relationship between these factors is presented in a simplified quantitative model, which is supported by data from limited welding trials. Metallographic observations suggest that acicular ferrite forms in two stages. The first involves the formation of relatively large primary acicular ferrite plates by multiple nucleation at intragranular inclusion sites, and the second involves the formation of many smaller acicular ferrite grains that grow sympathetically from the primary plates.
10.	Bengtsson, S., et al. (författare) Tensile behaviour of squeeze cast and forged short alumina fibre reinforced AA 6061 1993 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 9:4, s. 319-327 Tidskriftsartikel (refereegranskat)
11.	Bratberg, Johan, et al. (författare) Diffusion simulations of MC and M7C3 carbide coarsening in bcc and fcc matrix utilising new thermodynamic and kinetic description 2008 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 24:6, s. 695-704 Tidskriftsartikel (refereegranskat)abstract A new thermodynamic database has been combined with an existing kinetic database to perform coarsening simulations in ternary systems including MC and M7C3 carbides in an fcc matrix. The kinetic database was revised taking into consideration the new experimental information on the Fe-Cr-V-C system obtained in the present work, and available experiments on the ternary Fe-Cr-C and Fe-V-C systems. After revision the agreement between experimental results and simulations was satisfactory. It was found that the interfacial energy of M7C3 was twice as large as that of the MC carbide. The calculations for commercial steels with 6 alloy elements gave results in satisfactory agreement with new experimental measurements. The present coarsening simulations use the calculated equilibrium state and the observed particle sizes as the state for the start of the simulations. All the simulations were performed with the DICTRA software.
12.	Bratberg, Johan, et al. (författare) Diffusion simulations of MC and M7C3 carbide coarsening in bcc and fee matrix utilising new thermodynamic and kinetic description 2008 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 24:6, s. 695-704 Tidskriftsartikel (refereegranskat)abstract A new thermodynamic database has been combined with an existing kinetic database to perform coarsening simulations in ternary systems including MC and M7C3 carbides in an fee matrix. The kinetic database was revised taking into consideration the new experimental information on the Fe-Cr-V-C system obtained in the present work, and available experiments on the ternary Fe-Cr-C and Fe-V-C systems. After revision the agreement between experimental results and simulations was satisfactory. It was found that the interfacial energy of M7C3 was twice as large as that of the MC carbide. The calculations for commercial steels with 6 alloy elements gave results in satisfactory agreement with new experimental measurements. The present coarsening simulations use the calculated equilibrium state and the observed particle sizes as the state for the start of the simulations. All the simulations were performed with the DICTRA software. © 2008 Institute of Materials, Minerals and Mining.
13.	Chen, Kaixuan, et al. (författare) Effects of solute content on microstructure of nano precipitate-fine grain synergistically reinforced copper alloys 2020 Ingår i: Materials Science and Technology. - : Taylor and Francis Ltd.. - 0267-0836 .- 1743-2847. Tidskriftsartikel (refereegranskat)abstract Alloying of Fe, Co was reported to tailor microstructure of copper alloys into a nanoprecipitate-fine grain (NPFG) structure, i.e. nano-sized iron-rich precipitates dispersed inside refined grains. Here, we investigate the solute effect of Sn, Zn on NPFG structure in as-cast copper samples. Mechanisms are proposed to account for the solute effect on precipitate and grain features. Solutes restrict coarsening but facilitate undesirable morphology transition from spherical to angular of iron-rich precipitates. Meantime, solutes allow more precipitates to be active in the nucleation of copper and consequently induce finer grains. Minor Sn is added to optimise NPFG structure and leads to an excellent strength–ductility combination in Cu–1.5Fe–0.1Sn (wt-%) alloy. This work provides a solute-alloying strategy to achieve desired mechanical properties in metals.
14.	Chen, Kaixuan, et al. (författare) Precipitates-interaction capture of nano-sized iron-rich precipitates during copper solidification 2019 Ingår i: Materials Science and Technology. - : Taylor & Francis. - 0267-0836 .- 1743-2847. ; 35:9, s. 1028-1037 Tidskriftsartikel (refereegranskat)abstract Nano-sized iron-rich precipitates reinforced copper alloys achieve excellent mechanical properties. Capture mechanism of iron-rich precipitates into copper grains during solidification was described but needs further validation. Here, Cu-1.5Fe-0.5Co (wt-%) alloy is fabricated by gravity casting. Iron-rich precipitates in nano and submicron scale (mostly < 100 nm) are well dispersed in copper grain interior. Traditional pushing/engulfment transition (PET) models are used to interpret the capture process of iron-rich precipitates during copper solidification, but all fail to match the experimental results. The precipitates-interaction capture mechanism is most reasonable for describing the capture process.
15.	Claesson, Erik, et al. (författare) The effect of alloying elements on the corrosion resistance of brass 2016 Ingår i: Materials Science and Technology. - : Taylor and Francis Ltd.. - 0267-0836 .- 1743-2847. ; 32:17, s. 1794-1803 Tidskriftsartikel (refereegranskat)abstract A systematic study has been performed on the effect of alloying elements arsenic (As), antimony (Sb) and phosphorus (P) on the dezincification resistance of α-phase in brass. The result showed that P formed particles with Al and Fe already at relatively high temperatures, leaving no P in solid solution and thus no protection against dezincification. Arsenic only formed particles at lower temperatures and offers a satisfactory protecting. However, with increasing As levels grain boundary attack was observed. Samples alloyed with Sb show a satisfactory resistance to dezincification and no grain boundary attack. Finally, a combination of As and Sb at low alloying levels provided an excellent dezincification resistance for brass containing typical impurity levels. This paper is part of a Themed Issue on Brass Alloys. © 2016 Swerea KIMAB.
16.	Cong, DY, et al. (författare) Crystal structures and textures of hot forged Ni48Mn30Ga22 alloy investigated by neutron diffraction technique 2005 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 21:12, s. 1412-1416 Tidskriftsartikel (refereegranskat)abstract A ferromagnetic shape memory alloy of Ni48Mn30Ga22 prepared by induction melting was successfully hot forged. Strong textures and a large anisotropy of in plane plastic flow were developed during the hot forging process. The crystal structures, both in austenitic and martensitic states, were investigated by means of neutron powder diffraction technique. The result suggests that Ni48Mn30Ga22 has a cubic L2(1) Heusler structure at room temperature, the same as that in the stoichiometric Ni2MnGa. When cooled to 243 K, the Ni48Mn30Ga22 alloy changes into a seven layered orthorhombic martensitic structure. No substantial change of the neutron diffraction pattern was observed upon further cooling to 19 K, indicating that there is no intermartensitic transformation in the investigated alloy, which is different from the transformation processes in the Ni-Mn-Ga alloys with higher martensitic transformation temperatures.
17.	Cvetkovski, Krste, 1983, et al. (författare) Rapid thermomechanical tempering of iron–carbon martensite 2014 Ingår i: Materials Science and Technology. - 1743-2847 .- 0267-0836. ; 30:14, s. 1832-1834 Tidskriftsartikel (refereegranskat)abstract Tempering of martensite under simultaneous compressive stress has been studied within thetemperature range of 20–400 deg C. Resistive heating was utilised to obtain rapid heating and coolingcycles of a few seconds. Material was obtained from a medium carbon pearlitic railway wheelsteel, quench hardened to obtain martensitic structure. Above approx 150 deg C dilatation effectswere observed below the global yielding point of the material. Microstraining around dislocationsin the body centred tetragonal crystallographic structure or viscous flow at higher temperatureswas a probable explanation to this material behaviour. Hence, external stress may have animportant influence on the tempering progression of martensitic steel. The trials also showed thattempering of martensite progresses fast, is near instantaneous and is independent of thepresence of external stress or not.
18.	Cvetkovski, Krste, 1983, et al. (författare) Thermal degradation of pearlitic steels: influence on mechanical properties including fatigue behaviour 2011 Ingår i: Materials Science and Technology. - 1743-2847 .- 0267-0836. ; 27:3, s. 648-654 Tidskriftsartikel (refereegranskat)abstract With the aim to predict the durability of railway wheels, thermomechanical damage was studiedfor two steels with different alloying levels of silicon and manganese in the temperature range of500–725uC. Softening caused by cementite spheroidisation in pearlite leads to changes in themechanical behaviour and an accompanying decrease in fatigue lifetimes. It was found thathigher contents of Si and Mn lead to better resistance to softening of both virgin and plasticallydeformed material. Correspondingly, the high Si–Mn alloyed steel loses much less in fatiguelifetime than the lower alloyed steel.
19.	Dadbakhsh, Sasan, et al. (författare) Study on static strain aging of 6082 aluminium alloy 2010 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 26:2, s. 169-175 Tidskriftsartikel (refereegranskat)
20.	DAS, D.K., et al. (författare) High temperature oxidation behaviour of directionally solidified nickel base superalloy CM–247LC 2003 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 19:6, s. 695-708 Tidskriftsartikel (refereegranskat)abstract The present paper describes the isothermal and cyclic oxidation behaviour of the technologically important nickel base directionally solidified superalloy CM-247LC in air in the temperature range 1000-1200°C. This superalloy behaves as a transition nickel base alloy under isothermal oxidation conditions and exhibits a fairly long transient oxidation period (~20 h at 1100°C). Irrespective of the temperature of exposure and nature of oxidation (isothermal or cyclic), a composite oxide scale develops on CM-247LC. While the outer portion of the oxide scale consists of either spinel (NiAl2O4) or a mixture of spinel and NiO, depending on oxidation temperature, the inner portion is always constituted of alumina. Beyond the transient period, the alloy is found to follow parabolic oxidation kinetics. The oxide layer that forms is invariably very non-uniform in thickness, and is dispersed with two types of oxide particles. While tantalum rich oxide particles are found scattered in the outer zone of the oxide layer, hafnium rich oxide particles lie close to the oxide/metal interface. Results also reveal that the nature of oxidation associated with the CM-247LC superalloy causes entrapment of metal islands in the oxide layer.
21.	Das, Yadunandan B., et al. (författare) The influence of temperature on deformation-induced martensitic transformation in 301 stainless steel 2018 Ingår i: Materials Science and Technology. - : Taylor & Francis Group. - 0267-0836 .- 1743-2847. ; 34:17, s. 2114-2125 Tidskriftsartikel (refereegranskat)abstract Deformation-induced martensitic transformations are increasingly being used to create desirable mechanical properties in steels. Here, the kinetics of the deformation-induced martensitic transformation is investigated at 300, 263, 223, 173 and 100 K using in situ neutron diffraction during tensile loading. The results from these experiments show a distinct change in the transformation behaviour between 300 K and the tests conducted at 263 K and below, causing a difference in martensite structure. The difference in transformation kinetics is correlated to the suppression of slip at low temperatures, as evidenced using diffraction peak intensity analysis for different grain families and corroborated using transmission electron microscopy. A direct correlation between the deformation-induced martensite fraction and the work-hardening rate is shown.
22.	Desai, Ashish, et al. (författare) Numerical and experimental investigation on AZ91 friction stir welding joints : mechanics, properties 2023 Ingår i: Materials Science and Technology. - : Taylor & Francis Group. - 0267-0836 .- 1743-2847. ; 39:17, s. 1-15 Tidskriftsartikel (refereegranskat)abstract The present endeavour is to evaluate numerically and experimentally the influence of friction stir welding (FSW) parameters on peak temperatures, microstructures and mechanical properties of AZ91 magnesium alloy joints. A full 3D finite element ABAQUS model was developed to simulate the temperature distribution along the joint line. There from, a total of nine differ-ent parametric combinations were derived for experimentations. Important insights relating to the material flow patterns and grain morphologies observed while altering the processing parameters have been elaborated. The parametric influence on the peak temperatures, grain morphologies, intermittent phases, tensile strength, and hardness are discussed through several mechanisms. Remarkably, the specimens prepared with the highest tool rotation speeds exhibited superior properties owing to several strengthening mechanisms.
23.	Forouzan, Farnoosh, 1985-, et al. (författare) Process Control Maps to Design an Ultra-High Strength-Ductile Steel 2019 Ingår i: Materials Science and Technology. - : Taylor & Francis. - 0267-0836 .- 1743-2847. ; 35:10, s. 1173-1184 Tidskriftsartikel (refereegranskat)
24.	Fredriksson, Hasse, et al. (författare) Theory of hot crack formation 2005 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 21:5, s. 521-529 Tidskriftsartikel (refereegranskat)abstract The hot crack sensitivity in metals is suggested to be caused by the supersaturation of vacancies created during the solidification process. Equations have been derived to predict the nucleation and growth of cracks by the condensation of vacancies. The transition temperature from brittle to ductile fracture was found to be related to the decrease in the supersaturation of vacancies due to an annealing process. The hot crack sensitivity was observed to be related to the supersaturation of vacancies, the diffusion rate, and the structure coarseness. The effect of surface active elements such as phosphorous and sulphur in steel alloys is discussed.
25.	Frisk, Karin (författare) Simulation of precipitation of secondary carbides in hot work tool steels 2012 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 28:3, s. 288-294 Tidskriftsartikel (refereegranskat)abstract Precipitation of secondary carbides in hot work tool steels during tempering heat treatments has been investigated using simulations based on a thermodynamic description coupled with kinetic parameters through multicomponent nucleation and growth models. The simulations reproduce the measured effects of steel composition on the precipitation of secondary carbides. Both Si and V increase the volume fraction of fine secondary carbides precipitated during tempering provided that the austenitising temperature is adjusted to give the same fraction of retained primary carbides. The most important effect of Si in 5%Cr steels is its influence on the primary carbide stability at austenitisation temperatures, but increasing the V contents has a strong effect on the fraction of secondary carbides, without increasing the size, and can thus improve the yield strength. The most critical input to the calculations is the thermodynamic description of the individual phases. © 2012 Institute of Materials, Minerals and Mining.
26.	Garcia-Mateo, Carlos, et al. (författare) Nanostructured steel industrialisation : Plausible reality 2014 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 30:9, s. 1071-1078 Tidskriftsartikel (refereegranskat)abstract It is not the first time that a consortium of steel makers, end users and scientists end up with unique approaches and developments in the physical metallurgy of steels. The present paper reveals the scientific and technological developments of a consortium sharing a common intrigue and interest for a unique microstructure, nanostructured bainite. Also known as low temperature bainite, its unique properties rely solely on the scale of the miscrostructure obtained by heat treatment at low temperature (150-350°C). Careful design based on phase transformation theory, some well known metallurgy facts and the necessary industrial experience were the ingredients for a further step towards the industrialisation of these microstructures.
27.	Guo, Lulu, et al. (författare) Solidification structures and phases in wire arc additive manufactured C250 maraging steel 2023 Ingår i: Materials Science and Technology. - : Sage Publications. - 0267-0836 .- 1743-2847. ; 39:5, s. 582-590 Tidskriftsartikel (refereegranskat)abstract Multiple layers of C250 maraging steel were deposited into a single-wall structure by using wire arc additive manufacturing (WAAM). The microstructural characteristics of the as-deposited C250 steel, in terms of solidification structures and phases, were investigated by using optical microscopy, scanning electron microscopy, and transmission electron microscopy (TEM). The results show that lath martensite and austenite phases are formed in the as-deposited C250 steel. Apart from these two phases, Laves phase Fe2Ti particles, which have not been reported in C250 steel, are also observed in the C250 steel produced by the WAAM process. TEM analysis does not reveal the formation of strengthening precipitates in the as-built C250 steel, which is further confirmed by hardness measurement.
28.	Guo, Sheng, 1981 (författare) Phase selection rules for cast high entropy alloys: an overview 2015 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 1743-2847 .- 0267-0836. ; 31:10, s. 1223-1230 Tidskriftsartikel (refereegranskat)abstract This paper summarises existing phase selection rules for cast high entropy alloys. Essentially, they are almost all based on the parametric approach, utilising various descriptors comprising mixing enthalpy, configuration entropy, mismatch entropy, melting points, atomic size mismatch, electronegativity and valence electron concentration. The overview starts from phase selection rules for solid solutions, intermetallic compounds and the amorphous phase in high entropy alloys. Further discussions are relevant to selection rules for solid solution phases in high entropy alloys, more specifically, for face centred cubic and body centred cubic type solid solutions. Finally, some challenges and future prospects of phase selection rules for high entropy alloys are addressed.
29.	Heydarian, Abtin, et al. (författare) Characteristics evaluation of SiC/Si nanocomposites produced by spark plasma sintering 2019 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 35:10, s. 1204-1211 Tidskriftsartikel (refereegranskat)abstract SiC-Si composites are widely used either as a bulk material or as a matrix for fibre reinforced ceramics. In the current research, nanocomposites of SiC-Si with different volume fractions of Si were sintered by spark plasma sintering (SPS) for the first time. The effect of Si content and different sintering parameters on relative density, microstructure, hardness and fracture toughness of the sintered materials have been investigated. The relative density increased from about 83 to 99% by increasing the sintering temperature to 1700 degrees C, sintering time to 10 min, and pressure to 70 MPa for composites containing >20 vol.-% Si. The results revealed that the full dense SiC-20 vol.-%Si composite can be obtained by SPS at 1700 degrees C, 10 min and 70 MPa. Moreover, in this condition, the hardness and toughness of the composites reached the optimum values.
30.	Hou, Ziyong, 1986-, et al. (författare) On coarsening of cementite during tempering of martensitic steels 2020 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 36:7, s. 887-893 Tidskriftsartikel (refereegranskat)abstract The coarsening of cementite in a martensitic Fe–1C–1Cr (wt-%) alloy upon tempering at 700°C is investigated. When considering that the main location of cementite is at grain boundaries, classical coarsening theory can accurately predict the mean size evolution, while the predicted size distribution evolution disagrees with the experimentally observed log-normal distribution maintained throughout the whole tempering (5000 h). We conclude that classical theory of coarsening, as given by Lifshitz–Slyozov–Wagner and included in the Langer–Schwartz Kampmann–Wagner numerical approach for modelling precipitation reactions, is not fully adequate to simulate coarsening of cementite for tempering in practice.
31.	Hulme-Smith, Christopher, 1989-, et al. (författare) Further evidence of tetragonality in bainitic ferrite 2015 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 31:2, s. 254-256 Tidskriftsartikel (refereegranskat)abstract There is growing evidence that bainitic ferrite which retains a substantial amount of carbon in solid solution does not have cubic symmetry. We provide additional data on a different nanostructured bainitic steel to support this evidence, based on synchrotron X-ray diffraction experiments. The data are consistent only with a displacive transformation mechanism for bainite.
32.	Hulme-Smith, Christopher, 1989-, et al. (författare) Intermetallic-strengthened nanocrystalline bainitic steel 2018 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 34:16, s. 1976-1979 Tidskriftsartikel (refereegranskat)abstract A new thermally stable, nanocrystalline bainitic steel has been developed, rich in nickel and aluminium. During tempering, it is expected that a significant quantity of intermetallic precipitates will form. This was confirmed by X-ray diffractometry, scanning transmission electron microscopy, Fourier transform analysis of atomic column images, energy dispersive X-ray spectroscopy and selected area electron diffraction. These are the first intermetallics to be produced in a nanocrystalline bainitic steel.
33.	Hutchinson, Bevis (författare) Critical assessment 16 : Anisotropy in metals 2015 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 31:12, s. 1393-1401 Tidskriftsartikel (refereegranskat)abstract Sources of anisotropy in metals are discusssed as well as ways of interpreting and modelling this behaviour. A number of case studies are presented relating to mechanical and magnetic properties.
34.	Hutchinson, Bevek, et al. (författare) Observations of dynamic transformation products in a commercially hot-rolled steel 2018 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 34:10, s. 1197-1200 Tidskriftsartikel (refereegranskat)abstract Sufficient evidence has now accumulated to show that dynamic transformation (DT) is a real phenomenon in steels and can take place over a wide range of temperatures in the austenite regime. During plastic deformation, some of the austenite is transformed to ferrite despite austenite being the chemically more stable equilibrium phase. Occurrence of DT has been demonstrated in various laboratory tests but apparently not in commercially hot-rolled steels. In this note, we review some old results on high strength low alloy strip steel that contained microstructural features that appear to have been caused by DT. We deduce that DT occurred early in the rolling schedule, leading to thin-pancaked sheets of ferrite in the final product. The presence of these pre-existing ferrite nuclei frequently gave rise to adjacent regions of coarse polygonal ferrite grains during cooling.
35.	Hutchinson, Bevek, et al. (författare) Vanadium microalloying for ultra-high strength steel sheet treated by hot-dip metallising 2017 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 33:4, s. 497-506 Tidskriftsartikel (refereegranskat)abstract Ultra-high strength steel sheets have been subjected to heat treatments that simulate the thermal cycles in hot-dip galvanising and galvannealing processes and evaluated with respect to their resulting mechanical properties and microstructures. The steels contained suitable contents of carbon (∼0.2%), manganese (1.2%) and chromium (0.4%) to ensure that they could be fully transformed to martensite after austenitisation followed by rapid cooling in a continuous annealing line, prior to galvanising. Different contents of vanadium (0–0.1%) and nitrogen (0.002–0.012%) were used to investigate the possible role of these microalloying elements on the strength of the tempered martensite. Vanadium, especially when in combination with a raised nitrogen content, helps to resist the effect of tempering so that a larger proportion of the initial strengthening is preserved after the galvanising cycle, giving tensile strength levels exceeding 1000 MPa. Different deoxidation practices using aluminium or silicon have also been included. These showed similar strength levels at corresponding carbon contents but the bendability of the Si-killed steel sheet was considerably superior. Microstructural examinations have been made on the annealed steels but the reason for the beneficial effect of vanadium is still not fully explained. It is concluded that microalloying with vanadium is a very promising approach in the development of corrosion-resistant ultra-high strength steel sheet products.
36.	Hörnqvist Colliander, Magnus, 1979, et al. (författare) Temperature and strain rate dependence of the dynamic strain ageing effect in an Al-Zn-Mg alloy 2006 Ingår i: Materials Science and Technology. - 1743-2847 .- 0267-0836. ; 22:2, s. 213-222 Tidskriftsartikel (refereegranskat)abstract An AA7030 alloy (Al-5·4Zn-1·2Mg) was tested for evidence of dynamic strain aging in naturally aged and peak aged condition and under varying conditions in terms of strain rate and temperature. Clear evidence in terms of strain rate sensitivity, serrated yielding (Portevin-Le Chatelier effect) and propagative plastic instabilities was observed in the naturally aged temper while the peak aged temper only showed serrated yielding. Further evidence of dynamic strain aging was the temperature and strain dependence of the strain rate sensitivity, which can be explained by the additional dislocation activation energy resulting from solute pinning. Investigation of the specimen surfaces was carried out to reveal an orange peel structure with pronounced glide bands. Small cracks within individual grains rather than grain boundary cracking could be observed. © 2006 Institute of Materials, Minerals and Mining.
37.	Ion, John C., et al. (författare) Computer modelling of weld-implant testing 1985 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 1:5, s. 405-411 Tidskriftsartikel (refereegranskat)abstract A theoretical model is developed for determining the optimum notch position in an implant test used for predicting the susceptibility to hydrogen cracking during welding. Using a microcomputer for processing the equations for weld-bead geometry and heat flow during welding, a microstructural cross-section, with the notch positioned at the center of the grain-growth zone, and an implant testing diagram, showing the notch position and microstructure as a function of welding parameters, can be generated. A single bead-on-plate weld is used to determine the unknown kinetic and geometrical constants in the equations. It is shown that notch position is very sensitive to the type of welding process employed and that implant diagrams thus can be used to position the notch with greater reliability and hence reduce the scatter in the fracture loads measured in this test.
38.	Ion, John, et al. (författare) Laser transformation hardening of low alloy hypoeutectoid steel 1992 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 8:9, s. 799-804 Tidskriftsartikel (refereegranskat)abstract The principles of laser transformation hardening were investigated using a low alloy special steel having a microstructure of pearlite and proeutectoid ferrite. Temperature fields and phase transformations were modelled. Particular attention was paid to increases of the Ac1 and Ac3 transformation temperatures owing to the rapid thermal cycles produced by laser heating. Dissolution of proeutectoid ferrite is shown to control the formation of a homogeneous hardened case. Experimental data are in good agreement with the predictions of the model. A diagram was constructed which describes the case geometry and microstructure in terms of the process variables and is an aid to optimising practical processing parameters. The models are flexible and may be used for laser transformation hardening of other ferrous alloys having inhomogeneous microstructures.
39.	Jaradeh, Majed, et al. (författare) Analysis of solidification in a Bridgman furnace as a simulation of DC casting of aluminium alloy slabs 2007 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 23:4, s. 475-482 Tidskriftsartikel (refereegranskat)abstract The vertical Bridgman directional solidification equipment has been used in several investigations to simulate direct chill casting of wrought aluminium alloys. As a basis for such investigations and alloy developments, it is important to have an understanding of the performance of the furnace used during simulation of the casting conditions. In this investigation the thermal conditions in the furnace have been analysed in detail, both by measurements and by mathematical modelling. The growth characteristics of the furnace, such as gradient, growth rates and cooling rates have been compared to conditions in large ingots. The direct chill casting conditions, which the simulations have been compared to, are casting of slabs of 330 and 600 mm thickness of an aluminium AA3003 type alloy. The results show that the experiments are able to simulate the cooling conditions in the ingots except from the surface zone. Comparisons of the microstructures have been made and a good agreement has been obtained for structure parameters such as grain size and DAS.
40.	Jarfors, A. E. W. (författare) Peritecticlike precipitation of titanium carbide in Al-Ti-C melts at 1373 K 1999 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 15:5, s. 481-494 Tidskriftsartikel (refereegranskat)abstract The reaction between an Al-Ti melt and a carbon containing medium, i.e. pure graphite or molten aluminium containing aluminium carbide, was studied. Experiments were carried out at 1373 K, using three different experimental setups. Depending on the carbon source, titanium carbide precipitated as a layer or as free particles. Classical nucleation theory for homogeneous and heterogeneous nucleation is used to assess the surface tension. The influence of stoichiometry on surface tension and nucleation is discussed. The formation of a continuous layer, or peritecticlike precipitation of titanium carbide, is theoretically analysed. The growth of the layer is rate controlled by the mass transfer of carbon at the interface, plausibly as a result of the ordering tendencies in titanium carbide. The degeneration of precipitation into that of freely formed particles is found to be nucleation controlled. A model for degenerate precipitation is proposed, including predictions of the reaction front compositions, growth rate, and particle fractions in a dilute ternary system. The model is in good agreement with experiments, after compensating for settling of the precipitates, except in predicting the precipitated fractions. © 1999 IoM Communications Ltd.
41.	Jarfors, A. E. W. (författare) Solubility of copper in titanium carbide 1996 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 12:12, s. 990-994 Tidskriftsartikel (refereegranskat)abstract The solubility of copper in titanium carbide (TiCx) was studied experimentally. The solubility was assessed in two different ways: (a) titanium carbide was added to a copper-titanium melt, (b) titanium carbides formed in situ, from graphite and titanium, were analysed. The stoichiometries were implicitly assessed. The solubility of copper in titanium carbide was found to decrease with increasing carbon content. This behaviour was compared to the solubility of chromium in titanium carbide, which increases in solubility with increasing carbon content. The role of vacancies in the solution is briefly discussed. © 1996 The Institute of Materials.
42.	Kumara, Chamara, et al. (författare) Modelling of anisotropic elastic properties in alloy 718 built by electron beam melting 2018 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 34:5, s. 529-537 Tidskriftsartikel (refereegranskat)abstract Owing to the inherent nature of the process, typically material produced via electron beam melting (EBM) has a columnar microstructure. As a result of that, the material will have anisotropic mechanical properties. In this work, anisotropic elastic properties of EBM built Alloy 718 samples at room temperature were investigated by using experiments and modelling work. Electron backscatter diffraction data from the sample microstructure was used to predict the Youngâ€™s modulus. The results showed that the model developed in the finite element software OOF2 was able to capture the anisotropy in the Youngâ€™s modulus. The samples showed transversely isotropic elastic properties having lowest Youngâ€™s modulus along build direction. In addition to that, complete transversely isotropic stiffness tensor of the sample was also calculated. Â© 2018 Institute of Materials, Minerals and Mining.
43.	Li, Yan, et al. (författare) Microstructure and tensile properties of a 0.20C-4.86Mn steel after short intercritical-annealing times 2019 Ingår i: Materials Science and Technology. - : TAYLOR & FRANCIS LTD. - 0267-0836 .- 1743-2847. ; 35:2, s. 220-230 Tidskriftsartikel (refereegranskat)abstract This work studies the microstructure and tensile properties of a cold-rolled Fe-0.20C-4.86Mn (mass %) steel after short intercritical annealing (IA) times using scanning and transmission electron microscopy, and uniaxial tensile tests. The short IA time is applied to represent the process characteristics of the industrial continuous annealing line. The experimental results show that IA temperature has a strong influence on the final microstructure and tensile properties while IA time has less. The fractions of retained austenite are much higher after IA at 650 and 675 degrees C than the other IA temperatures, and thus improving elongation. Simulations using the DICTRA software and constitutive modelling are further performed to assist the understanding of the microstructure evolution and stress-strain curves.
44.	Liu, Xihe, et al. (författare) CNT-reinforced AlSi10Mg composite by selective laser melting : microstructural and mechanical properties 2019 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 35:9, s. 1038-1045 Tidskriftsartikel (refereegranskat)abstract Carbon nanotube (CNT)-AlSi10Mg composites were fabricated by selective laser melting (SLM). The influence of CNTs on the density, microstructure, and strength of SLM CNT-AlSi10Mg composites was investigated. The addition of CNTs over 0.1 wt-% significantly damaged the density due to the high surface energy of the CNTs. The network Si eutectic had no significant difference in either the SLM AlSi10Mg alloy or the CNT-AlSi10Mg composite. Reserved CNTs with a short scale were observed in the SLM CNT(0.5 wt-%)-AlSi10Mg composite. The ultimate tensile strength of the 0.05 wt-% CNT-AlSi10Mg composite was 441.2 +/- 0.9 MPa, which was higher than that of AlSi10Mg alloy. The grain boundary strengthening played an important role in the reinforcement of CNT-AlSi10Mg composite because of the refined grain.
45.	Markaki, A. E., et al. (författare) Biomaterial characterisation 2015 Ingår i: Materials Science and Technology. - 0267-0836 .- 1743-2847. ; 31:2, s. 129-130 Tidskriftsartikel (refereegranskat)
46.	Moverare, Johan (författare) Thermal-Mechanical Fatigue Behavior of CMSX-4 in Virgin and Long Term aged Condition 2007 Ingår i: Materials Science and Technology. - : Maney Publishing. - 0267-0836 .- 1743-2847. ; 23:12, s. 1450-1453 Tidskriftsartikel (refereegranskat)abstract The thermal–mechanical fatigue (TMF) behaviour of the single crystal alloy CMSX-4 has been investigated under out of phase (OP) loading in the 100–1000°C temperature range with a dwell period of 5 min. The material was tested in both virgin and aged conditions. Even though aging at 1000°C for 4000 h seems to have no significant influence on the OP TMF life, a more ductile fracture appearance was generally found for the aged material. This is also illustrated by the difference in the shape of the stabilised stress–strain hysteresis loop between virgin and aged materials, where one can see a higher degree of inelastic deformation for the aged material due to a higher degree of creep relaxation during the dwell period and more plastic deformation in the cold end of the TMF cycle. Microstructure studies showed that rafting occurred in the virgin material even during a short term TMF test with a maximum temperature of 1000°C, which may explain some of the similarities in terms of cyclic life between the two tested material conditions. The rafting was however more pronounced in the aged material where topologically close-packed phases also were found.
47.	Navara, Eric, et al. (författare) Austenite formation in manganese-partitioning dual-phase steel 1986 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 2:12, s. 1196-1201 Tidskriftsartikel (refereegranskat)abstract Manganese-containing ferritic-pearlitic steels have been studied after intercritical annealing for various times at temperatures of 700 and 725 degree C, during which austenite formation occurred at ferrite grain boundaries. Light and electron optical microscopy, and scanning transmission electron microanalysis and microdiffraction were employed for the study, in which both microstructural development and manganese redistribution were examined in detail. It was observed that the formation of austenite is associated initially with a migration of ferrite grain boundaries. It is proposed that this boundary migration is induced by manganese diffusion along the boundaries, and that this in turn provides the mechanism for rapidly transporting manganese to the growing austenite. On this basis, we find that austenite formation in these steels is associated with manganese-rich migrated ferrite boundaries, and is not dependent on the presence of cementite particles for nucleation
48.	Navara, E., et al. (författare) Investigation of microstructural changes occurring during warm working of manganese partitioned dual phase steel 1990 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 6:2, s. 151-155 Tidskriftsartikel (refereegranskat)abstract This paper presents results from studies using transmission and high resolution electron microscopy of as-received and warm worked manganese partitioned dual phase steel. A growing manganese enriched austenite grain shares two different boundaries with ferrite: (a) a stationary coherent boundary, replacing a stretch of the original ferrite/ferrite boundary, and (b) a migrating non-coherent boundary. This finding gives support to a previously described mechanism of the nucleation and growth of the manganese enriched austenite. The structure of the warm worked steel consists of recovered ferrite strengthened by substructure, and fine martensitic lathes separated by low angle boundaries which resulted from the transformation of deformed non-recrystallised austenite grains
49.	Olafsson, P., et al. (författare) Calculations of electrical resistivity for Al-Cuand Al-Mg-Sialloys 2001 Ingår i: Materials Science and Technology. - : Maney Publishing. - 0267-0836 .- 1743-2847. ; 17:6, s. 655-662 Tidskriftsartikel (refereegranskat)abstract A system for thermodynamical calculations (Thermo-Calc) was used to derive the solid solubility of the alloying elements in commercial Al-Cu and Al-Mg-Si alloys. The electrical resistivity was then calculated using a model developed by the authors based on the Matthiessen's rule. The calculated resistivity agreed with the observed resistivity within +/-2.5 n Omegam for the Al-Mg-Si alloys and +/- 2n Omegam for the Al-Cu alloys, except for Al-Mg-Si alloys containing boron or chromium and AI-Cu alloys with special compositions. MST/3725.
50.	Ooi, S. W., et al. (författare) Designing steel to resist hydrogen embrittlement Part 2 : precipitate characterisation 2018 Ingår i: Materials Science and Technology. - : Informa UK Limited. - 0267-0836 .- 1743-2847. ; 34:14, s. 1747-1758 Tidskriftsartikel (refereegranskat)abstract A novel, low-alloy steel has been designed for use in the oil and gas industry. Its high strength and hydrogen trapping potential are derived from a martensitic microstructure containing a dispersion of fine vanadium-molybdenum alloy carbides that evolve during tempering. In this second paper, the effect of quench rate from austenitisation and tempering conditions are investigated with respect to the microstructure. The alloy loses its tempering resistance following slow-cooling from austenitisation as a result of MC precipitation, leading to vanadium depletion and significant M2C coarsening. This is predicted using computer simulation and confirmed by high energy X-ray diffraction, combined with electron microscopy.

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