| 1. |
- Agmell, Mathias, et al.
(författare)
-
A numerical and experimental investigation of the deformation zones and the corresponding cutting forces in orthogonal cutting
- 2011
-
Ingår i: Advanced Materials Research. - 1022-6680 .- 1662-8985. - 9783037850954 ; 223, s. 152-161
-
Konferensbidrag (refereegranskat)abstract
- Abstract in UndeterminedThis study are focused on the deformation zones occurring in the work piece in a machining process and the corresponding cutting forces. The fully coupled thermo-mechanical FE-model for orthogonal cutting, developed in [1] is utilized. The work piece material is modeled with Johnson-Cook plasticity including damage formulation. Simulations for different feed depths were performed. The cutting forces, the chip thickness ratio and the deformation widths were determined experimentally by the quick-stop images and a force measurements. The results from the simulations have been compared to experimental data for the cutting forces and the chip thickness ratio as a function of the theoretical chip thickness.
|
|
| 2. |
- Altaie, Entidhar, et al.
(författare)
-
Progress of building materials and foundation engineering in ancient Iraq
- 2012
-
Ingår i: Advanced Materials Research. - 1022-6680 .- 1662-8985. ; , s. 220-241
-
Tidskriftsartikel (refereegranskat)abstract
- Humans realised the importance of housing since the dawn of history. The first man used the caves as shelter. When agricultural activities dominated the life style of humans, villages started to be constructed. Later these were developed into cities. The dawn of civilization started in Iraq. The inhabitants in that time used the available natural materials in their construction. Reviewing the progress of engineering practices of ancient Iraq, reveals the facts that the inhabitants were aware of the principles of construction and engineering. The materials used and the design of the buildings were very suitable from both environmental and engineering perspectives. This work is a critical review of the progress and development of engineering practices and construction materials used in ancient Mesopotamia
|
|
| 3. |
- Bhaskar, U., et al.
(författare)
-
On-chip tensile testing of the mechanical and electro-mechanical properties of nano-scale silicon free-standing beams
- 2011
-
Ingår i: Advanced Materials Research. - 1662-8985 .- 1022-6680. ; 276, s. 117-126
-
Tidskriftsartikel (refereegranskat)abstract
- A simple and versatile on-chip tensile testing method is proposed for the statistical evaluation of size effects on the mechanical strength of silicon thin films along with the simultaneous study of (from low to ultra) strain effects on the carrier transport. Mechanical results are presented on the fracture strength of micro-nano scale silicon beams, followed with a discussion on interface states and problems facing reliable nano-electronic and nano-electromechanical characterizations
|
|
| 4. |
- Brommesson, Rebecka, 1985, et al.
(författare)
-
Low-Cycle Fatigue Crack Growth in Ti-6242 at Elevated Temperature
- 2014
-
Ingår i: Advanced Materials Research. - 1662-8985 .- 1022-6680. ; 891-892, s. 422-427
-
Konferensbidrag (refereegranskat)abstract
- During low-cycle fatigue test with smooth bars the number of cycles to initiation is commonly defined from a measured relative drop in aximum load. This criterion cannot be directly related to the actual measure of interest - the crack length. By relating data from controlled crack growth tests under low-cycle fatigue conditions of a high strength Titanium alloy at 350°C and numerical simulation of these tests, it is shown that it is possible to determine the relationship between load drop and crack length, provided that care is taken to consider all relevant aspects of the materials stress-strain response.
|
|
| 5. |
- Calmunger, Mattias, et al.
(författare)
-
Influence of deformation rate on mechanical response of an AISI 316L austenitic stainless steel
- 2014
-
Ingår i: Advanced Materials Research. - : Trans Tech Publications Inc.. - 1022-6680 .- 1662-8985. ; 922, s. 49-54
-
Tidskriftsartikel (refereegranskat)abstract
- Austenitic stainless steels are often used for components in demanding environment. These materials can withstand elevated temperatures and corrosive atmosphere like in energy producing power plants. They can be plastically deformed at slow strain rates and high alternating or constant tensile loads such as fatigue and creep at elevated temperatures. This study investigates how deformation rates influence mechanical properties of an austenitic stainless steel. The investigation includes tensile testing using strain rates of 2*10-3/ and 10-6/s at elevated temperatures up to 700°C. The material used in this study is AISI 316L. When the temperature is increasing the strength decreases. At a slow strain rate and elevated temperature the stress level decreases gradually with increasing plastic deformation probably due to dynamic recovery and dynamic recrystallization. However, with increasing strain rate elongation to failure is decreasing. AISI 316L show larger elongation to failure when using a strain rate of 10-6/s compared with 2*10-3/s at each temperature. Electron channelling contrast imaging is used to characterize the microstructure and discuss features in the microstructure related to changes in mechanical properties. Dynamic recrystallization has been observed and is related to damage and cavity initiation and propagation.
|
|
| 6. |
- Caprioli, Sara, 1978, et al.
(författare)
-
Influence of short thermal cracks on the material behaviour of a railway wheel subjected to repeated rolling
- 2014
-
Ingår i: Advanced Materials Research. - 1662-8985 .- 1022-6680. - 9783038350088 ; 891-892, s. 1139-1145
-
Konferensbidrag (refereegranskat)abstract
- An analysis of whether and how the occurrence of shallow (radial) thermal cracks promotes additional plastic deformation of a mechanically loaded wheel tread is carried out. The study employs numerical simulations of a 2D slice of an elastoplastic railway wheel tread containing thermal (radial) cracks. The cracked wheel material is subjected to repeated passes of a frictional rolling contact load. The effect of the existing thermal cracks on bulk deformation and subsequent rolling contact promoted growth is quantified. Results indicate that thermal cracks of a depth of 0.1 mm have a negligible effect, whereas 1.0 mm cracks significantly decrease the bulk resistance of the wheel material. Further, it is shown how the magnitude of stress, strain and deformation depends on the direction of applied traction.
|
|
| 7. |
- Ceron, Ermanno, et al.
(författare)
-
Lubricant film breakdown and material pick-up in sheet forming of advanced high strength steels and stainless steels when using environmental friendly lubricants
- 2014
-
Ingår i: Advanced Materials Research. - : Trans Tech Publications Inc.. - 1022-6680 .- 1662-8985. ; 966-967, s. 219-227
-
Tidskriftsartikel (refereegranskat)abstract
- Increasing focus on environmental issues in industrial production has urged sheet metal stamping companies to look for new tribo-systems in order to substitute hazardous lubricants such as chlorinated paraffin oils. The efficiency of chlorinated paraffin is due to the fact that the lubricant reacts chemically with the tool and workpiece material forming thin films, which adhere strongly to the surfaces and reduce the tendency to metal-metal contact and material pick-up. Production tests of new, environmentally benign tribo-systems are, however, costly and laboratory tests are preferred as a preliminary simulative method to investigate alternative tribo-systems. The present paper presents a case study where an industrial process, consisting of deep drawing with two subsequent re-drawings, was selected and four potential new tribo-systems were tested including different workpiece materials, i.e. AHSSs and stainless steels. The performance of the tribo-systems was analyzed in the laboratory by means of a newly developed simulative test as well as in an industrial production process. The results obtained show a good agreement between the laboratory test and the industrial production process regarding the tribological performance, i.e. tendency to material pick-up and galling, of the evaluated tribo-systems. Moreover the SEM analysis shows that different workpiece materials result in different types of material pick-up.
|
|
| 8. |
- Cwirzen, Andrzej
(författare)
-
Controlling physical properties of cementitious matrixes by nanomaterials p1
- 2010
-
Ingår i: Advanced Materials Research. - 1022-6680 .- 1662-8985. ; 123-125, s. 639-642
-
Tidskriftsartikel (refereegranskat)abstract
- The majority of concrete used nowadays is based on matrixes formed by hydrating Portland cement. Latest developments in nanosciences introduced a new generation of nano-sized materials possessing often remarkable mechanical and physical properties. These materials can be also used to improve or alter the characteristics of the binder matrixes based on Portland cement. The results showed that mechanical properties such as compressive and flexural strength can be increased by up to 50% by addition of for example 0.23wt% of carbon nanotubes. Carbon nanotubes and carbon nanofibres and/or nanosilica appeared to improve also the frost resistance. Other properties, such as autogenous shrinkage decreased significantly after addition of carbon nanofibres. Nanosilica enabled an immense densification of the hydrated binder matrix, which in turn improved for instance the durability and mechanical properties. © (2010) Trans Tech Publications.
|
|
| 9. |
- Deng, Liang, et al.
(författare)
-
Implementation of wear models for stamping tools under press hardening conditions based on laboratory tests
- 2014
-
Ingår i: Advanced Materials Research. - 1022-6680 .- 1662-8985. ; 1063, s. 339-342
-
Tidskriftsartikel (refereegranskat)abstract
- Tool wear occurring in press hardening processes receives insufficient attention since its corresponding measurements and full-scale experiments are complicated and expensive. This paper presents a study of tool wear in press hardening based on laboratory experiments and FE-simulations. Two experimental laboratory setups depending on the contact conditions in press hardening build the base for the wear models implemented in the FE-simulation to predict wear depths. The highest wear depth is found at the radius of the stamping tool and the discrepancies in wear predictions based on the two different laboratory test setups are analyzed.
|
|
| 10. |
- Ding, C., et al.
(författare)
-
Study on fracture of the fibrous monolith cemented carbide
- 2013
-
Ingår i: Advanced Materials Research. - 1662-8985 .- 1022-6680. ; 815, s. 43-47
-
Konferensbidrag (refereegranskat)abstract
- A fibrous monolith cemented carbide with WC-6%Co as cell and WC-20%Co as cell boundaries was produced through hot co-extrusion process in this paper. The density, hardness, transverse rupture strength (TRS) and fracture toughness (KIc) of the fibrous monolith cemented carbide were tested, and the fracture and crack propagation were observed by metalloscope and Scanning Electron Microscope. The result shows fibrous monolith structure design could effectively improve the TRS and the KIc of WC/Co cemented carbide without a significant decrease of hardness. It is the reason of high transverse rupture strength and fracture toughness that WC-20%Co can absorb more fracture energy in order to slow, prevent, or deflect crack propagation, proved by metalloscope and scanning electron microscope.
|
|
