FATIGUE CRACK GROWTH PERFORMANCE OF TI-6AL-4V TITANIUM ALLOY BY SELECTIVE LASER MELTING
ZHANG HaiYing
LI Gang
ZANG WeiFeng
LIAO JiangHai
DONG DengKe
Abstract：Compact tension specimens were fabricated with Ti-6Al-4V titanium alloy by selective laser melting.Some specimens were heat treated and some were hot-isostatic pressed(HIPed).Half of these specimens in three conditions were polished.Fatigue crack growth(FCG)test was conducted to obtain FCG data,and to research into the effect of post-processes.The microstructure and fractography were observed to find possible reasons for FCG variaton.The results indicated that,FCG preformance of as-built SLM Ti-6Al-4V is inferior to conventional material due to the fine needle martensitic α structure and large residual stress.Both heat treatment and hot-isostatic pressing lead to thicker α phase and more β phase,diminsh or even eliminate the residual stress,and improve FCG performance signifcantly.FCG rates of heat treated and HIPed speicmens are comparable to those of Ti-6Al-4V fabricated by conventional techonology.When the crack length and stress intensity factor are larger than a certain value,surface polishing shows haldly any effect.
Keywords：Selective laser meltHeat treatmentHot-isostatic pressSurface conditionFatigue crack growth
Publication Date：2023-12-15
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：6( 1355-1360 )