Selective laser melting Al-Si aluminum alloy and the crack formation mechanism

WANG Mengyao; ZHU Haihong; QI Ting; ZHANG Hu; ZENG Xiaoyan

doi:10.7510/jgjs.issn.1001-3806.2016.02.014

To get Al-Si alloy parts with high performance, the formation and cracking behaviors of Al-Si alloy parts fabricated by selective laser melting were studied. The relationship between process parameters and fabrication densification, and the mechanism of crack formation were revealed. The results show that the density of the fabricated samples increases at first and then decreases with the increase of laser power density. The cold cracks are formed in most of the samples which expand along the cladding layer. Its formation mechanism is that a large number of eutectic Si is formed during the process and eutectic Si reduces crack resistance strength of Al-Si aluminum alloy, and crack resistance cannot be enough to resist the high temperature gradient during the forming process, and the generated residual stress is the cause of cold cracks. By improving the process parameters, Al-Si alloy parts with high performance and without cracks could be formed.

Selective laser melting Al-Si aluminum alloy and the crack formation mechanism

Corresponding author: ZHU Haihong, zhuhh@mail.hust.edu.cn;

1. Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China

Received Date: 2015-02-03

Accepted Date: 2015-03-12

Available Online: 2016-03-25

Abstract: To get Al-Si alloy parts with high performance, the formation and cracking behaviors of Al-Si alloy parts fabricated by selective laser melting were studied. The relationship between process parameters and fabrication densification, and the mechanism of crack formation were revealed. The results show that the density of the fabricated samples increases at first and then decreases with the increase of laser power density. The cold cracks are formed in most of the samples which expand along the cladding layer. Its formation mechanism is that a large number of eutectic Si is formed during the process and eutectic Si reduces crack resistance strength of Al-Si aluminum alloy, and crack resistance cannot be enough to resist the high temperature gradient during the forming process, and the generated residual stress is the cause of cold cracks. By improving the process parameters, Al-Si alloy parts with high performance and without cracks could be formed.

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Reference (16)

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Selective laser melting Al-Si aluminum alloy and the crack formation mechanism

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