Effect of Annealing on Microstructures and Properties of TC4 Heat Dissipation Structure Prepared by LPBF

Abstract

TC4 (Ti6Al4V) alloy is widely used in aerospace, medical equipment, food industry and other fields. Laser powder bed fusion (LPBF) technology has a short production cycle and high precision for formed parts, providing new ideas for the manufacturing of complex structures such as aerospace and having great development prospects and manufacturing advantages. This paper took the TC4 heat dissipation structure prepared by LPBF technology as the study object and established a numerical simulation model to analyze the temperature field changes of the TC4 heat dissipation structure prepared by LPBF. By adopting the annealing heat treatment process, it was found that with the increase in annealing temperature and holding time, the microstructure coarsened, the hardness first increased and then decreased, and the corrosion resistance improved. Among them, when the annealing temperature was 900 °C, and the α' phase was basically transformed into α phase, and the content of β phase increased. The grains and structure of the heat dissipation structure were uniform, and the most significant was in the near inner-pore area. At this point, the hardness value significantly decreased, and the difference in hardness around and outside the heat dissipation hole was 12.42 HV0.2.

Keywords

• LPBF
• TC4 alloys
• microstructure
• mechanical properties
• annealing