固溶时效对TC21钛合金准β锻后组织性能的影响  

Effect of Solution Aging Treatment on Microstructure Properties of TC21 Titanium Alloy After Quasi-βForging

作　　者：徐浩 孙前江[1] 文超 马鑫 牛冬阳 Xu Hao;Sun Qianjiang;Wen Chao;Ma Xin;Niu Dongyang(School of Aeronautical Manufacturing Engineering,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学航空制造工程学院,江西南昌330063

出　　处：《稀有金属材料与工程》2024年第1期178-187,共10页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51965043)。

摘　　要：对TC21钛合金进行准β锻造,再进行固溶时效热处理实验,研究了不同固溶时效热处理制度对合金的微观组织和力学性能的影响。结果表明,TC21钛合金通过准β锻造后,再经固溶时效热处理后,合金的微观组织呈现典型的网篮组织。随着固溶温度的上升,片状α相含量和长度显著降低,同时合金强度增加,抗拉强度可达1269 MPa,而断裂韧性和塑性变化呈相反趋势,合金最大断裂韧性值可达71.7MPa·m^(1/2)。随着时效温度的上升,对片状α相的影响略小,但次生α相的厚度此时显著增加,此时合金强度降低,抗拉强度为1218 MPa,塑性和断裂韧性值提高。断口形貌则随着固溶温度的升高,断口表面和裂纹扩展路径愈发平坦。考虑合金的强度、塑性和断裂韧性之间的良好匹配,经综合分析可得,TC21钛合金准β锻后最佳热处理制度为:870℃/2 h, AC+590℃/4 h, AC,此时合金抗拉强度为1250MPa,延伸率为6.61%,断裂韧性为64.6 M P a·m^(1/2)。The quasi-βforging of TC21 titanium alloy was conducted,and then the alloy was treated by the solution aging heat treatment experiment.The effects of different solution aging heat treatment systems on the microstructure and mechanical properties of the alloy were investigated.The results show that after TC21 titanium alloy was forged by quasi-βand treated by solution aging heat treatment process,the microstructure of the alloy presents a typical basket-weave structure.With increasing the solution temperatures,the content and length of the lamellarαphase are decreased significantly,the strength of the alloy is increased,the tensile strength can reach 1269 MPa,whereas while the plasticity change shows the opposite trend,and the maximum fracture toughness can reach 71.7 MPa·m^(1/2).With increasing the aging temperature,the effect on the lamellarαphase is slightly smaller,but the thickness of the secondaryαphase is increased significantly.The strength of the alloy decreases,the tensile strength is 1218 MPa,and the plasticity increases.The fracture morphology of the alloy becomes flatter with increasing the solution temperature,and the crack growth path also becomes flatter.The fracture toughness value presents a downward trend,but it is increases with increasing the aging temperature.Considering the good match among the strength,plasticity,and fracture toughness of the alloy,after comprehensive analysis,it can be obtained that the best heat treatment system of TC21 titanium alloy after quasi-βfracture is:870℃/2 h,AC+590℃/4 h,AC.The tensile strength,elongation,and fracture toughness are 1250 MPa,6.61%,and 64.6 MPa·m^(1/2),respectively.

关 键 词：TC21钛合金 准β锻造 热处理 力学性能 微观组织 

分 类 号：TG146.23[一般工业技术—材料科学与工程]