时效处理对固溶冷拉态TB9钛合金组织与性能的影响

Effect of aging treatment on microstructure and properties of solution treated and cold-drawn TB9 titanium alloy

研究了不同时效处理(450~600℃×8 h)对固溶冷拉态TB9钛合金组织和力学性能的影响。结果表明:随着时效温度的升高,TB9钛合金的组织结构发生显著变化。在450~500℃时效温度下,α相细小且均匀分布,显著提高了合金的硬度和强度,但塑性较差;在550~600℃时效温度下,α相尺寸和体积分数增加,晶粒组织趋于均匀。时效温度对强度和塑性有重要影响,450℃时效时,合金强度达到峰值,约1700 MPa,而伸长率几乎为零;随着时效温度的升高,合金强度逐渐降低,伸长率逐渐增加,550℃时效时,抗拉强度约1400 MPa,伸长率约14%;600℃时效时,抗拉强度约1200 MPa,伸长率约22%。较低温度(500℃)时效时,合金断口为脆断特征,较高温度(600℃)时效时,合金断口为韧性特征。因此,为保证TB9钛合金获得较优的强塑性匹配,最佳时效温度为550~600℃。

Effect of aging treatment at 450-600 C for 8 h on the microstructure and mechanical properties of solution treated and cold drawn TB9 titanium alloy was investigated.The results show that the microstructure of the TB9 alloy changes significantly with aging temperature.When aged at 450-500 C,fine and uniformly distributedα-phase precipitates,which significantly enhances hardness and strength but results in poor plasticity.When aged at 550-600℃,the size and volume fraction ofα-phase increase,leading to more uniform grain structures.Aging temperature has a significant impact on strength and plasticity.When aged at 450 C,strength reaches a peak of about 1700 MPa with nearly zero elongation.As the aging temperature increases,the strength decreases,while the elongation increases.When the aging time is 550℃,the strength is about 1400 MPa and the elongation is 14%.At 600℃,the strength is 1200 MPa and the elongation is 22%.The tensile fracture characteristics show brittle fracture at lower temperature(500℃)and ductile fracture at higher temperature(600℃).Therefore,to achieve an optimal balance of strength and plasticity for TB9 titanium alloy,the recommended aging temperature is 550-600℃.