固溶和时效处理对选区激光熔化成形GTD222镍基合金组织和硬度的影响  

Effect of Solid Solution and Aging Treatment on Microstructure and Hardness of Selective Laser Melting GTD222 Nickel-Based Alloy

作　　者：潘纬韬 祝国梁(指导)[1] 王瑞[1] 汪东红[1] 董安平[1] 疏达[1] 孙宝德[1] PAN Weitao;ZHU Guoliang;WANG Rui;WANG Donghong;DONG Anping;SHU Da;SUN Baode(Shanghai Key Laboratory of Advanced High-Temperature Materials and Precision Forming,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学,上海市先进高温材料及其精密成形重点实验室,上海200240

出　　处：《机械工程材料》2020年第11期66-71,共6页Materials For Mechanical Engineering

基　　金：国家自然科学基金资助项目(51871147,51704195,51821001)。

摘　　要：采用选区激光熔化成形技术制备GTD222镍基合金并进行了1150℃固溶和时效处理,研究了固溶处理时间(0,20,40,60,120 min)、时效温度(760,780,800,820,840℃)和时效时间(2,4,8 h)对显微组织和硬度的影响。结果表明:选区激光熔化成形GTD222合金中的柱状晶与成形方向呈一定倾斜角度,合金中存在胞状亚结构和高密度位错,未析出γ’相,MC碳化物主要分布于晶界及相邻亚结构界面处;经1150℃固溶处理后合金中的亚结构均消失,随着固溶时间的延长,碳化物逐渐溶解,合金显微硬度先下降后趋于稳定;在760~840℃时效处理2~8 h后,合金基体中析出大量γ’相,γ’相的尺寸随时效时间延长和时效温度升高而增大,合金硬度则随时效时间延长和时效温度降低而增大。The GTD222 nickel-based alloy was prepared by selective laser melting technique and then treated by solution at 1150℃and aging.The effects of solution treatment time(0,20,40,60,120 min),aging temperature(760,780,800,820,840℃)and aging time(2,4,8 h)on the microstructure and hardness of the alloy were studied.The results show that the columnar crystals in the GTD222 alloy formed by selective laser melting had a certain oblique angle to the forming direction.There were cellular substructures and high-density dislocations in the alloy,noγ’phase was precipitated,and MC carbides mainly distributed at grain boundaries and interfaces of adjacent substructures.The substructures of the alloy disappeared after solution treatment at 1150℃.With increasing solution time,the carbides gradually dissolved,and the alloy hardness decreased first and then became stable.After aging at 760-840℃for 2-8 h,a large number ofγ’phases were precipitated in the alloy matrix.The size ofγ’phase increased with aging time and temperature,while the hardness of alloy increased with increasing aging time and decreasing aging temperature.

关 键 词：增材制造 选区激光熔化 GTD222镍基高温合金 显微组织 热处理 

分 类 号：TN249[电子电信—物理电子学]