| 1. |
- Kryshtal, O., et al.
(författare)
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Microstructure and phase composition of the Ag-Al film wear track : Through-thickness characterization by advanced electron microscopy
- 2019
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Ingår i: Archives of Metallurgy and Materials. - : POLSKA AKAD NAUK, POLISH ACAD SCIENCES, INST METALL & MATER SCI PAS. - 1733-3490 .- 2300-1909. ; 64:1, s. 251-256
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Tidskriftsartikel (refereegranskat)abstract
- Analytical transmission electron microscopy has been applied to characterize the microstructure, phase and chemical composition of the Ag-Al wear track throughout its thickness down to the atomic level. Microscopy findings have been correlated with Ag-Al film tribological properties to understand the effect of the hexagonal solid solution phase on the tribological properties of this film. Ag-25Al (at.%) films have been produced by simultaneous magnetron sputtering of components in Ar atmosphere under 1 mTorr pressure and subjected to pin-on-disc tribological tests. It has been shown that hcp phase with (001) planes aligned parallel to the film surface dominates both in as-deposited and in tribofilm areas of the Ag-Al alloy film. Possible mechanisms of reduced friction in easily oxidized Ag-Al system are discussed and the mechanism based on readily shearing basal planes of the hcp phase is considered as the most probable one.
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| 2. |
- Svidró, Judit, et al.
(författare)
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The influence of thermal expansion of unbonded foundry sands on the deformation of resin bonded cores
- 2017
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Ingår i: Archives of Metallurgy and Materials. - : De Gruyter Open. - 1733-3490 .- 2300-1909. ; 62:2, s. 795-798
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Tidskriftsartikel (refereegranskat)abstract
- Depending on the preparation and the applied materials, moulds and cores can be of high rigidity or can be flexible. Although, chemically bonded moulding materials have relatively good flexibility, their high temperature behaviour determines the dimensional accuracy, the stresses in the castings and can induce several casting defects, such as rattail, veining, etc. The phenomenon is based on two major effects: the thermal expansion of the unbonded foundry sands and the deformation of the sand mixtures. The main objective of the present work was to study the relationship between these two effects, and to improve the knowledge related to the thermo-mechanical interactions between the casting and the mould. Dilatometric analysis of unbonded sand samples were performed and compared to the results of hot distortion tests of moulding mixture specimens. The results showed, that the thermal expansion of foundry sand largely influences the hot distortion behaviour, but depending on the type of binder used.
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| 3. |
- Chychko, Andrei, et al.
(författare)
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ENERGY SAVING EFFECT OF SLAG FOAMING BY CARBONATE ADDITIONS IN EAF PROCESS
- 2010
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Ingår i: ARCH METALL MATER. - : Polish Academy of Sciences Chancellery. - 1733-3490. ; 55:4, s. 1089-1095
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Tidskriftsartikel (refereegranskat)abstract
- Slag foaming has been studied systematically for more than 50 years. The main reason for such interest is a big number of benefits of slag foaming technology in steelmaking, especially for the process in an electric arc furnaces (EAF). There are 2 types of reactions which can be used for slag foaming. The most famous one is the carbon oxidation by oxygen dissolved in metal. Another type of slag foaming reactions is a decomposition of carbonates or other substances, which can produce gas at high temperature. However, it can be concluded that the slag foaming with carbonates is not usual in steelmaking practice. The purpose of the present work is to study the energy effect of slag foaming caused by carbonates decomposition.
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| 4. |
- Teng, Lidong, et al.
(författare)
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RETENTION, RECOVERY AND RECYCLING OF METAL VALUES FROM HIGH ALLOYED STEEL SLAGS
- 2010
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Ingår i: ARCH METALL MATER. - : Polish Academy of Sciences Chancellery. - 1733-3490. ; 55:4, s. 1097-1104
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Tidskriftsartikel (refereegranskat)abstract
- The work was carried out in four parallel directions. The thermodynamic activities of oxides of Cr in steel slags were determined by slag-gas equilibration technique. The ratio of Cr2+/Cr3+ in CaO-MgO(-FeO)-AlO3-SiO2-CrO(x)system slags was measured by X-ray absorption near edge spectra (XANES). High-temperature mass spectrometry method was also used to obtain the distribution of chromium oxides. A mathematical correlation was established for estimating the ratio of Cr2+/Cr3+ as a function of temperature, partial pressure of oxygen and slag basicity. Laboratory investigations of the decarburization of high alloy steels under controlled oxygen potentials have been carried out to retain Cr in the steel phase. A mathematical model has been developed for the decarburization process with controlled oxygen partial pressure. Experimental and theoretical investigations have been carried out in optimizing the Mo-additions to steel in the EAF practice in Uddeholm Tooling AB. Substantial saving of Mo as well as less emissions of Mo-bearing dust are indicated in the study. A salt extraction process was developed to extract the metal values from steel slags. Successful extractions, followed by electrolysis indicate that this could be a viable route towards recovery of metals from metallurgical slags.
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