TY - JOUR
T1 - Numerical analysis of the effect of the scan strategy on the residual stress in the multi-laser selective laser melting
AU - Zou, Sheng
AU - Xiao, Hanbin
AU - Ye, Fangping
AU - Li, Zongchen
AU - Tang, Wenzhi
AU - Zhu, Feng
AU - Chen, Chentong
AU - Zhu, Chao
PY - 2020
Y1 - 2020
N2 - The inevitably formed residual stress in the Selective Laser Melting (SLM) process leads to distortion, crack and even delamination of the workpiece. Single laser is commonly applied during SLM processing. However, its productivity is much lower than multiple lasers. In addition, the research of residual stress with multi-laser condition currently is limited in the open documents. In this paper, a three-dimensional (3D) thermo-mechanical model, with considerations of temperature dependent properties of Ti-6Al-4V, phase change and convective flow, is developed at first. Then, the numerical results of maximum temperature and dimensions of the molten pool are validated by available experimental data. Furthermore, a parametric study in regards to a series of scan strategies is investigated. According to the simulation results, the residual stress increases significantly when the laser number reaches four. The “two-zone technique” scan strategy decreases the equivalent residual stress by 10.6% compared to the successive scan strategy. With a shortening scan length, the residual stress first increases slightly, then decreases dramatically and attains the minimum when it is a quarter. Furthermore, for the multi-laser SLM process, carefully planning the scanning sequence and the sweeping direction to decrease heat concentration is beneficial in controlling the residual stress.
AB - The inevitably formed residual stress in the Selective Laser Melting (SLM) process leads to distortion, crack and even delamination of the workpiece. Single laser is commonly applied during SLM processing. However, its productivity is much lower than multiple lasers. In addition, the research of residual stress with multi-laser condition currently is limited in the open documents. In this paper, a three-dimensional (3D) thermo-mechanical model, with considerations of temperature dependent properties of Ti-6Al-4V, phase change and convective flow, is developed at first. Then, the numerical results of maximum temperature and dimensions of the molten pool are validated by available experimental data. Furthermore, a parametric study in regards to a series of scan strategies is investigated. According to the simulation results, the residual stress increases significantly when the laser number reaches four. The “two-zone technique” scan strategy decreases the equivalent residual stress by 10.6% compared to the successive scan strategy. With a shortening scan length, the residual stress first increases slightly, then decreases dramatically and attains the minimum when it is a quarter. Furthermore, for the multi-laser SLM process, carefully planning the scanning sequence and the sweeping direction to decrease heat concentration is beneficial in controlling the residual stress.
KW - Multi-laser
KW - Residual stress
KW - Scan strategy
KW - Selective laser melting
KW - Thermo-mechanical model
UR - http://www.scopus.com/inward/record.url?scp=85079534115&partnerID=8YFLogxK
U2 - 10.1016/j.rinp.2020.103005
DO - 10.1016/j.rinp.2020.103005
M3 - Article
AN - SCOPUS:85079534115
SN - 2211-3797
VL - 16
JO - Results in Physics
JF - Results in Physics
M1 - 103005
ER -