期刊名称:Lecture Notes in Engineering and Computer Science
印刷版ISSN:2078-0958
电子版ISSN:2078-0966
出版年度:2018
卷号:2235&2236
页码:836-841
出版社:Newswood and International Association of Engineers
摘要:Selective Laser Sintering (SLS) is an additive
manufacturing technique in which thin layers of fine powder
are fused by selective sintering with a high-powered laser to
create a 3D part directly based on a digital instruction file. A
characteristic aspect of the process is the high cooling rate
experienced by the deposited material volume, which gives rise
to directional cooling and the generation of columnar
microstructure. The fabrication of fine sub-millimetre features
leads to the modification of heat flow patterns that in turn
affects the microstructure produced. Electron Backscattered
Diffraction (EBSD) mapping was performed on samples of 316
stainless steel consisting of a set of thin (sub-mm) strut
structures protruding from a thick base. This sample geometry
was chosen to reveal the role of the transition from a bulk base
(representing a large heat sink) to a thin strut (unidirectional
heat conduction) in this additive manufacturing process. EBSD
data was collected from the base region, the transition region
between the base and the strut, and in the strut region. This
allows examining the effect of the heat flow difference between
the strut region and the base region on sample microstructure.
The greater temperature gradients in the strut region lead to
significantly refined grain structure compared to the base
region.