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Densification and microstructural evolution during laser sintering of A356/SiC composite powders
733 viewed

Densification and microstructural evolution during laser sintering of A356/SiC composite powders

Simchi, A

Densification and microstructural evolution during laser sintering of A356/SiC composite powders

Simchi, A ; Sharif University of Technology

733 Viewed
  1. Type of Document: Article
  2. DOI: 10.1007/s10853-010-4943-0
  3. Abstract:
  4. 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 lower densification kinetics. The densification was improved when finer SiC particles were utilized. Microstructural studies revealed directional solidification of aluminum melt to form columnar grains with inter-columnar silicon precipitates. In the presence of SiC particles, aluminum melt reacted with the ceramic particles to form Al4SiC4 plates
  5. Keywords:
  6. A-356 aluminum alloy ; Aluminum melts ; Argon atmospheres ; Ceramic particle ; Columnar grain ; Composite powders ; Densification kinetics ; Energy dispersive x-ray spectroscopy ; Laser sintering ; Micro-structural ; Microstructural development ; Phase formations ; Scan rates ; SiC particles ; Sintering atmospheres ; Sintering kinetics ; Aluminum ; Aluminum metallurgy ; Argon lasers ; Densification ; Energy dispersive spectroscopy ; Laser heating ; Powders ; Scanning electron microscopy ; Silicon carbide ; X ray diffraction ; Sintering
  7. Source: Journal of Materials Science ; Volume 46, Issue 5 , 2011 , Pages 1446-1454 ; 00222461 (ISSN)
  8. URL: http://link.springer.com/article/10.1007%2Fs10853-010-4943-0