摘要
对TC20钛合金进行不同的固溶时效处理,通过室温拉伸试验和平面应变断裂韧性试验,结合光学显微镜、扫描电镜和显微维氏硬度计等测试方法,分析了不同的固溶时效处理工艺参数对TC20钛合金显微组织、力学性能和断口形貌的影响。结果表明:当固溶温度一定时,随着时效温度的升高,合金的强度和硬度提高,塑性和韧性下降。当固溶时效工艺为950℃/0.5 h(水冷,WQ)+500℃/4 h(空冷,AC)时,合金可实现良好的强韧性匹配,此时合金的抗拉强度为1106 MPa,屈服强度为1019MPa,断裂韧性高达87.6MPa·m1/2。未经固溶时效处理的锻态TC20钛合金拉伸和紧凑拉伸(CT)试样,其断口呈现典型的韧性断裂形貌特征,而经不同固溶时效处理的试样断口主要以准解理断裂和解理断裂为主。随着时效温度的升高,拉伸试样断口表面逐渐出现二次裂纹和空洞,塑性逐渐降低,CT试样的韧窝尺寸逐渐变小变浅,断裂韧性逐渐降低。
TC20 titanium alloy was subjected to different solution aging treatments. The effects of different solution aging treatment parameters on microstructure, mechanical properties and fracture morphology of TC20 titanium alloy were analyzed by tensile test at room temperature and plane strain fracture toughness test, combined with optical microscope, scanning electron microscope and micro Vickers hardness tester. The results show that when the solution temperature is constant, the strength and hardness of the alloy increase, while the plasticity and toughness decrease with the increase of the aging temperature. When the solution aging process is at 950 ℃ for 0.5 h with water quenching, and then aging at 500 ℃ for 4 h with air cooling, the alloy can reach a good strength and toughness match. At this time,the tensile strength of the alloy is 1106 MPa, the yield strength is 1019 MPa, and the fracture toughness is as high as 87.6 MPa·m1/2. The fractures of the forged TC20 titanium alloy tensile and compact tensile(CT) specimens without solution aging treatment show typical ductile fracture morphology characteristics, while the fractures of the specimens treated with different solution aging treatments are mainly quasi-cleavage fracture and cleavage fracture. As the aging temperature increases, secondary cracks and voids on the fracture surface of the tensile specimen gradually appear, the plasticity gradually decreases, the size of the dimples of the CT specimen gradually becomes smaller and shallower, and the fracture toughness gradually decreases.
作者
钟明君
王克鲁
鲁世强
欧阳德来
崔霞
李鑫
Zhong Mingjun;Wang Kelu;Lu Shiqiang;Ouyang Delai;Cui Xia;Li Xin(Nanchang Hangkong University,Nanchang 330063,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2021年第6期2149-2154,共6页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51761029,51864035)。
关键词
TC20钛合金
固溶时效
显微组织
力学性能
断裂韧性
TC20 titanium alloy
solution aging
microstructure
mechanical properties
fracture toughness
