( 1. 西安交通大学 材料科学与工程学院，西安 710049;
2. 西北有色金属研究院， 西安 710016)
摘 要: 研究了Ti-B20合金（以“临界钼当量条件下的多元强化”为原则设计的一种新型的高强度亚稳β钛合金）在不同热处理条件下的时效组织和拉伸性能。 结果表明：同常见的亚稳β钛合金相比， Ti-B20合金具有更快的时效响应及更高的时效强化效应，其析出相更加细小均匀； 合金在α-β区固溶后在500～600 °C时效时可以获得优良的强度和塑性匹配 (抗拉强度: 1 200～1 500 MPa; 延伸率: 8%～18%)， 高温时效时没有发现无析出区； 合金在β区固溶后的时效强度要大大高于α-β区固溶后的时效强度， 但却会导致拉伸塑性的急剧降低。 所有的这些时效特征都来源于合金成分的独特性。
关键字: Ti-B20； 临界钼当量； 亚稳β钛合金； 时效
（ 1. School of Materials Science and Engineering,
Xi'an Jiaotong University, Xi'an 710049, China;
2. Northwest Institute for Nonferrous Metal Research,
Xi'an 710016, China）
Abstract: The aging microstructures and properties of Ti-B20 alloy, a new high strength metastable beta titanium alloy which was designed according to the principle of ‘critical molybdenum equivalence and multi-components strengthening’, were investigated under different heat treatment conditions. The results show that compared to traditional metastable β titanium alloys, Ti-B20 alloy has more rapid aging response, much higher aging strengthening effect and much finer but homogeneous depositions. After α-β solution and 500-600°C aging treatment, excellent strength and plasticity properties can be achieved(ultimate tensile strength: 1 200-1 500 MPa; elongation: 8%-18%) and no precipitate-free regions have been found during high temperature aging treatment. Beside, the aging strength of alloy after solution treatment in β region is considerably higher than that in α-β region. But β solution and aging treatment will lead to remarkable decrease of tensile ductility. All these aging characteristics of Ti-B20 alloy are responsible for its specific components.
Key words: Ti-B20; critical molybdenum equivalence; metastable β titanium alloy; aging
