激光重熔对激光粉末床熔合制备Ti-6Al-4V合金热稳定性的影响机制研究
Effect of Laser Remelting on Thermal Stability of Ti-6Al-4V Alloy Prepared by Laser Powder Bed Fusion
詹宇星 1杨扬1
作者信息
- 1. 中南大学 材料科学与工程学院,湖南 长沙 410083
- 折叠
摘要
研究了激光重熔(LR)对激光粉末床熔合(LPBF)制备Ti-6Al-4V合金的组织性能和热稳定性的影响.结果表明,LR处理后,LRed-Ti-6Al-4V钛合金样品内α'相热稳定性显著提升,β-Ti相出现的温度点由 500℃升至 700℃.热处理后,LPBF-Ti-6Al-4V钛合金内晶粒持续生长,700℃以上出现明显的"短棒状"和"粗层片状"特征;而LRed-Ti-6Al-4V样品表层熔化区内晶粒仍维持等轴特征,700℃以上的熔化区和热影响区内呈现较为均匀细小的针状组织.两组样品的表面显微硬度值随温度升高而不断降低,并且分别在 700℃和 850℃显著下降,β-Ti晶粒的迅速粗化是引起硬度下降的主要原因.
Abstract
The effect of laser remelting(LR)on the microstructure property and thermal stability of Ti-6Al-4V alloy prepared by laser powder bed fusion(LPBF)was investigated.The results show that after LR treatment,the thermal stability of the α'phase within the LRed-Ti-6Al-4V titanium alloy samples is significantly improved,and the temperature at which β-Ti phase appears is up from 500 ℃ to 700 ℃ .After heat treatment,the grains in LPBF-Ti-6Al-4V titanium alloy grow continuously,and obviously appear to be"short bar-like"and"coarse lamellar"at the temperature above 700℃;while the grains in the melting zone of the surface layer of the LRed-Ti-6Al-4V sample are still maintain equiaxial,and the relatively uniform and fine needle-like microstructure are observed in the melting zone and heat affected zone above 700℃.The surface microhardness of those two groups of samples decreases with the increased temperature,especially significant at 700 ℃ and 850 ℃ respectively.It is found that the rapid coarsening of β-Ti grains is the main reason for the falling down of hardness.
关键词
增材制造/3D打印/激光粉末床熔合/激光重熔/Ti-6Al-4V/退火热处理/热稳定性Key words
additive manufacturing/3D printing/laser powder bed fusion(LPBF)/laser remelting(LR)/Ti-6Al-4V/annealing heat treatment/thermal stability引用本文复制引用
基金项目
国家自然科学基金(51871243)
国家自然科学基金(51574290)
出版年
2024
NETL
NSTL
万方数据