摘要
利用选区激光熔化技术制备Inconel 718合金,对其在不同温度、时间和冷却条件下进行热处理。采用扫描电子显微镜、电子背散射衍射仪和显微硬度计研究不同热处理工艺条件下Inconel 718合金的微观组织与硬度。结果表明:当热处理温度为1080℃时,沉积态合金中的束状亚结构消失、第二相含量减少,随着保温时间的延长,晶粒开始由非均匀柱状晶转变为再结晶晶粒,残余应力集中区和小角度晶界逐渐减少,并且形成<111>60°退火孪晶,硬度从292 HV降低至253 HV;当热处理温度为1130℃时,沉积态合金中的非平衡组织全部发生再结晶,残余应力集中区基本消失,晶粒内部出现均匀的退火孪晶,硬度保持在220 HV左右;对于1080℃/60 min热处理试样,随炉冷却方式的硬度高达431 HV,其较高的硬度主要与随炉冷却形成大量的亚结构和析出相有关。
Inconel 718 alloy was prepared by selective laser melting technique and then processed under different temperature,time and cooling conditions.The microstructure and hardness of Inconel 718 alloy under different heat treatment conditions were investigated by scanning electron microscope,electron backscattering diffractometer and microhardness tester.The results show that when the heat treatment temperature is 1080℃,the bundle substructure in the deposited alloy disappears and the content of the second phase decreases.With the increase of the heat treatment time,the grains start to change from non-uniform columnar grains to recrystallized grains,the residual stress concentration areas and small-angle grain boundaries gradually decrease,and<111>60°annealing twins are formed,the hardness decreases from 292 HV to 253 HV.When the heat treatment temperature is 1130℃,all the non-equilibrium structures in the deposited alloy recrystallize,the residual stress concentration area almost disappears,the uniform annealing twins appeared in the grains,and the hardness remained at about 220 HV.The hardness of sample heat treated at 1080℃/60 min is as high as 431 HV,and the higher hardness is mainly related to the formation of a large number of substructures and precipitates with furnace cooling.
作者
郭宇豪
赵学平
白朴存
曹宇
侯小虎
刘飞
GUO Yuhao;ZHAO Xueping;BAI Pucun;CAO Yu;HOU Xiaohu;LIU Fei(College of Materials Science and Engineering,Inner Mongolia University of Technology,Hohhot 010051,China)
出处
《中国表面工程》
EI
CAS
CSCD
北大核心
2021年第2期114-121,共8页
China Surface Engineering
基金
国家自然科学基金(11672140,11762014)
内蒙古自治区科技重大专项(ZDZX2018031)
内蒙古自治区科技计划(201803005)资助项目
作者简介
通信作者:白朴存,男,1967年出生,博士,教授。主要研究方向为轻质材料。E-mail:pcbai@imut.edu.cn
