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sintering-kinetics
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Densification and microstructural evolution during laser sintering of A356/SiC composite powders
, Article Journal of Materials Science ; Volume 46, Issue 5 , 2011 , Pages 1446-1454 ; 00222461 (ISSN) ; Godlinski, D ; Sharif University of Technology
Abstract
This article reports experimental results on laser sintering of A356 aluminum alloy and A356/SiC composite powders. Effects of scan rate, sintering atmosphere, hatch spacing, and SiC volume fraction (up to 20%), and particle size (7 and 17 μm) on the densification were studied. The phase formation and microstructural development were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS). Laser sintering under argon atmosphere exhibited higher densification compared to nitrogen. A faster sintering kinetics was observed as the scan rate decreased. Except at a low SiC content (5 vol%), the composite powders exhibited...
Solid state and liquid phase sintering of mechanically activated W-20 wt.% Cu powder mixture
, Article Journal of Alloys and Compounds ; Volume 463, Issue 1-2 , 8 September , 2008 , Pages 153-159 ; 09258388 (ISSN) ; Simchi, A ; Sharif University of Technology
2008
Abstract
W-20 wt.% Cu powder mixture was mechanically alloyed by high-energy ball milling for various times and the effect of mechanical alloying (MA) on the sintering response of the composite compacts was investigated. The densification, microstructure, hardness and electrical conductivity after solid phase sintering (SPS) and liquid phase sintering (LPS) were examined. It was shown that the microstructure of mechanically alloyed powder profoundly influence the sintering response, i.e. a meaningful relationship between the sintering kinetics and the milling time was observed. It is suggested that MA disintegrates the W-W particle networks and increases the contribution of solid phase sintering...
Advanced steel powder for direct metal laser sintering
, Article European Powder Metallurgy Congress and Exhibition, Euro PM 2005, Prague, 2 October 2005 through 5 October 2005 ; Volume 3 , 2005 , Pages 35-40 ; 9781899072187 (ISBN) ; Pohl, H ; Simchi, A ; Alcantara, B ; Sharif University of Technology
European Powder Metallurgy Association (EPMA)
2005
Abstract
Recent advances in material issues for Direct Metal Laser Sintering (DMLS) process are presented. The concept is to decrease the powder particle size with the aim of enhancing the sintering kinetics and improving the surface quality of the produced parts. The outcome is particularly suitable for overcoming existing limitations with the rapid tooling, e.g. manufacturing of mould inserts for injection moulding and die casting, by the DMLS process. The powder composition was adapted near to the conventional P/M steels in order to get identical properties with a favourable price. Such novel powder material provides an opportunity to considerably reduce the product development time for P/M...