A novel experimental method for in situ strain measurement during selective laser melting

Autor: Yaojie Wen, Baicheng Zhang, Shuying Liu, Wei Cai, Pei Wang, Coryl Jing Jun Lee, Junda Ma, Xuanhui Qu
Jazyk: angličtina
Rok vydání: 2020
Předmět:
Zdroj: Virtual and Physical Prototyping, Vol 15, Iss S1, Pp 583-595 (2020)
Druh dokumentu: article
ISSN: 1745-2759
1745-2767
17452759
DOI: 10.1080/17452759.2020.1842137
Popis: Selective laser Melting (SLM), a powder bed-based additive manufacturing technology, has been developed and applied in multiple industrial fields in the last decade. However, the distortion and swelling in the SLM process resulting from thermal stress cannot be predicted subject to measurement. In this work, an in situ distortion measurement system applied to the SLM process is presented. The distortion behaviour of component under laser scanning can be precisely recorded in real-time by this system. The detailed evolution and driving force of specimen distortion in the SLM process are discussed based on the experimental results. The distortion in single laser scanning presents a strong instantaneous upward motion of the central section during laser heating and a relatively slow downward recovery motion of the central section during cooling. The distortion behaviour of the sample with and without a layer of metal powder are compared, and laser scanning on the bare sample surface leads to a significantly higher residual distortion. The influence of SLM parameter variables (such as scanning speed, laser power, scanning width, layer thickness and scanning times) on SLM distortion is also analysed. At last, the stress distribution of laser melting is verified by the high-resolution EBSD analysis.
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