不同时效温度下激光增材再制造IN718合金层的组织与性能研究

Microstructure and Properties of Laser Additive Remanufactured IN718 Alloy Treated with Different Aging Temperatures

摘要:

研究了不同时效处理对激光增材再制造IN718合金组织及性能的影响。研究表明,时效处理不能改变激光增材再制造IN718合金的外延生长组织特征,但在微观上能够影响Laves在枝晶间的含量和形态。在不同时效温度条件下,随着时效时间的增加,γ 相逐渐长大并在保温一定时间后发生γ 相到δ相的转变,且时效温度越高,所需时间越短。此外,不同时效温度下处理后的修复区显微硬度和抗拉强度随时间均表现出先增后减的趋势。720 ℃条件下,显微硬度在时效16 h时出现峰值410 HV_0.2,而760 ℃和800℃条件下时效4 h时出现峰值,分别为385 HV_0.2和361 HV_0.2。720 ℃、760℃及800 ℃时效条件下不同时效时间对应的抗拉强度最大值分别1153 MPa,1090 MPa和1026 MPa。

Abstract:

The effects of aging treatment on the microstructure and properties of laser additive remanufactured IN718 alloy were studied. The results show that the aging treatment can not change the epitaxy growth structure of laser additive remanufactured IN718 alloy, but it will affect the content and morphology of Laves phase. With increase of the aging time, γ phase gradually grows up and changes to δ after holding for a certain time at different aging temperatures. The higher aging temperature, the shorter the time required. In addition, the microhardness and tensile strength of the repaired zone increase firstly and then decrease with holding time at different aging temperatures. The peak value of microhardness is 410 HV_0.2 at 720 ℃ for 16 h, 385 HV_0.2 and 361 HV_0.2 at 760 ℃ and 800 ℃ for 4 h, respectively. The maximum values of tensile strength corresponding to different aging time at 720 ℃, 760 ℃ and 800 ℃ are 1153 MPa, 1090 MPa and 1026 MPa, respectively.