In order to improve the mechanical properties of laser melting deposition(LMD)TC31 high-temperature titanium alloy,the influence of annealing temperature on the microstructure evolution and mechanical properties was studied by using OM,SEM,TEM and mechanical property tests.The results revealed that the primary α phase content decreases with the increase in annealing temperature during single-stage annealing.The dissolution mainly occurs above 950 ℃,and then its content is only 29％at 980 ℃ after annealing.When the annealing temperatures exceeds 930 ℃,the width of the primary α phase dendrites significantly increases.As the annealing temperature increases,the size of the(Ti,Zr)6Si3 phase precipitated at the α/β interface increases and enters the interior of the α lamellae.The room-temperature yield strength tends to decrease with increasing annealing temperature when the alloy is annealed at 800 ℃ to 1 000 ℃.Due to the factors such as the growth of aggregated precipitates at phase interfaces and the increase in the size of αphase dendrites,the high-temperature yield strength of the alloy firstly decreases and then increases with increasing annealing temperature during annealing.The alloy exhibits excellent high-temperature mechanical properties after annealing at 1 000 ℃,with a tensile strength of 657 MPa,yield strength of approximately 466 MPa,and an elongation of 27％at 650 ℃.
关键词
高温钛合金/激光熔化沉积/组织与性能调控/高温性能/退火
Key words
high-temperature titanium alloys/laser melting deposition/microstructure and property regula-tion/high temperature mechanical properties/annealing
维普
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