| 1. |
- Cabo Rios, Alberto, 1990, et al.
(författare)
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Modelling of δ-ferrite transformation effect on the sintering behaviour of 316L binder jetted components
- 2022
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Ingår i: World PM2022 Proceedings. - 9781899072552 - 9781899072552
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Konferensbidrag (refereegranskat)abstract
- The main objective of this study is to develop a simulation methodology that accounts for phase transformation (δ-ferrite) during the sintering of 316L stainless steel binder jetted (BJ) components. The model was based on the continuum theory of sintering develop by Skorohod and Olevsky. Dilatometry sintering tests at different heating rates up to 1370°C were performed. The constitutive parameters for the sintering model were obtained by dilatometry data analysis. Dilatometry results at different heating rates showed minor influence of the δ-ferrite transformation kinetics on the material viscosity. Thus, a new temperature-dependent material viscosity function was proposed to include the δ-ferrite transformation. The new model proposed was used to predict the densification behaviour of 316L BJ samples subjected to dilatometry experiments at different temperatures and times. The influence of δ-ferrite on the densification was accurately predicted for the material and sintering conditions studied.
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| 2. |
- Cinca, N., et al.
(författare)
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Friction, Material Transfer And Wear Phenomena In Sliding Contacts Between Cemented Carbide And Aluminum During Metal Forming
- 2022
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Ingår i: World PM 2022 Congress Proceedings. - : European Powder Metallurgy Association (EPMA). - 9781899072552
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Konferensbidrag (refereegranskat)abstract
- In many metal forming processes, certain texturization of the tool is necessary to have some friction that can make the operation possible. One example of that is the use of crosshatching methods on cemented carbide punches to manufacture beverage cans. The deep drawing and ironing process of the aluminum foil during can production involves different wear mechanisms being active on the punch surface, i.e. adhesive and abrasive wear. The present work examines the abrasive wear performance and friction characteristics of two cemented carbide grades by means of scratch and linear reciprocating sliding wear testing with Al2O3 counterparts under dry and lubricated conditions, with smooth polished and textured cemented carbide surfaces respectively. Additionally, well-controlled tests in which an aluminum pin is sliding over the cemented carbide surface were performed to evaluate the initial metal transfer. Post-test characterization shows the influence of carbide microstructure on the friction, material transfer and wear mechanisms. © European Powder Metallurgy Association (EPMA)
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| 3. |
- Javadzadeh Kalahroudi, Faezeh, et al.
(författare)
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High-Nitrogen PM Tool Steel : A Comparison Of Microstructure And Mechanical Properties Of As-HIPed And HIPed Followed By Hot Working
- 2022
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Ingår i: World PM 2022 Congress Proceedings. - : European Powder Metallurgy Association (EPMA). - 9781899072552
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- High-nitrogen-chromium alloyed powder metallurgy (PM) tool steels offer many attractive features including high strength and corrosion resistance. The PM route offers various advantages such as advanced alloy composition, high homogeneity, and well-defined size distribution of hard phase particles. This study presents microstructure and mechanical properties of a PM Cr-Mo-V-N alloy. The conventional manufacturing route for this alloy is hot isostatic pressing (HIP) followed by hot working. To investigate the possibility of near-net-shape manufacturing, a comprehensive comparison of the performance was made between steels produced by as-HIPed and HIPed followed by hot working. Both steel types were heat treated in the same way to obtain martensitic matrix with limited retained austenite. In the present investigation, microstructure and phase analyses were performed by X-ray diffraction and scanning electron microscopy. Mechanical tests were carried out by hardness measurements and tensile fatigue tests in the very high cycle fatigue regime using ultrasonic fatigue testing.
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| 4. |
- Şelte, Aydın, et al.
(författare)
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Industrial Development and Verification of Cr-Mo-V Based Cold Work Tool Steel Parts Produced Via Electron Beam Melting (EBM)
- 2022
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Ingår i: World PM 2022 Congress Proceedings. - : European Powder Metallurgy Association (EPMA). - 9781899072552
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Being a fast, powerful and crack-free manufacturing process, electron beam melting (EBM) has been gaining importance for tooling industry for the recent years. EBM allows processing high melting materials under vacuum atmosphere with high building rates, which offers less residual stresses caused by the complex thermal history and high cooling rates during the manufacturing. Uddeholms AB has previously shown on a pilot scale the performance capabilities of the EBM process in respect to the high alloyed and commercially available tool steel powder grade Vanadis® 4 Extra AM. In this study, industrial scale demonstrators and application tools were produced from Vanadis® 4 Extra AM powder. Industrialization of the concept studies was completed. Verification of the parts were conducted by using a slider-on-flat-surface (SOFS) wear tester and a semi-industrial punching test. Moreover, the dimensional tolerances, need of post processing treatments and product qualities were emphasized within the scope of this investigation. © European Powder Metallurgy Association (EPMA)
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