Residual Stress Control Using Process Optimization in Directed Energy Deposition

Manping Cheng; Xi Zou; Yang Pan; Yan Zhou; Wenyang Liu; Lijun Song

doi:10.3390/ma16196610

Residual Stress Control Using Process Optimization in Directed Energy Deposition

Materials (Basel). 2023 Oct 9;16(19):6610. doi: 10.3390/ma16196610.

Authors

Manping Cheng^{1

2}, Xi Zou³, Yang Pan³, Yan Zhou⁴, Wenyang Liu², Lijun Song²

Affiliations

¹ Research Institute of Automobile Parts Technology, Hunan Institute of Technology, Hengyang 421002, China.
² State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body, Hunan Provincial Key Laboratory of Intelligent Laser Manufacturing, Hunan University, Changsha 410082, China.
³ School of Mechanical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China.
⁴ School of Information Engineering, Hubei University of Economics, Wuhan 430205, China.

Abstract

This paper mainly analyzes the typical thermodynamic response (thermal history, thermal strain and residual stress) in a conventional continuous-wave (CW) laser during Directed Energy Deposition (DED). The influence of process parameters (laser power and scanning speed) on the temperature gradient in the heat-affected zone, thermal strain and residual stress are studied, and the corresponding relationship are established. The results show that a reduction in residual stress can be obtained by decreasing the temperature gradient. However, the method of reducing the temperature gradient by changing process parameters leads to low forming quality and low density. A pulse-wave laser (PW) is proposed to actively control the residual stress of the deposited sample. This laser mode can reduce not only the temperature gradient in the process of DED but also the in situ release of thermal stress, correspondingly greatly reducing the residual stress.

Keywords: 316L stainless steel; additive manufacturing; process parameters; residual stress; thermodynamic response.

Grants and funding

This research was funded by the National Natural Science Foundation of China (grant number 12272132), the Hunan Provincial Department of Education Youth Project (grant number 22B0495), the Hunan Provincial Natural Science Foundation General Project (grant number 2023JJ30254) and the Scientific Research Project of Hunan Institute of Technology (grant number HQ23011).