( 1. 西安交通大學 材料科學與工程學院，西安 710049;
2. 西北有色金屬研究院， 西安 710016)
摘 要: 研究了Ti-B20合金（以“臨界鉬當量條件下的多元強化”為原則設(shè)計的一種新型的高強度亞穩(wěn)β鈦合金）在不同熱處理條件下的時效組織和拉伸性能。 結(jié)果表明：同常見的亞穩(wěn)β鈦合金相比， Ti-B20合金具有更快的時效響應(yīng)及更高的時效強化效應(yīng)，其析出相更加細小均勻； 合金在α-β區(qū)固溶后在500～600 °C時效時可以獲得優(yōu)良的強度和塑性匹配 (抗拉強度: 1 200～1 500 MPa; 延伸率: 8%～18%)， 高溫時效時沒有發(fā)現(xiàn)無析出區(qū)； 合金在β區(qū)固溶后的時效強度要大大高于α-β區(qū)固溶后的時效強度， 但卻會導致拉伸塑性的急劇降低。 所有的這些時效特征都來源于合金成分的獨特性。
關(guān)鍵字: Ti-B20； 臨界鉬當量； 亞穩(wěn)β鈦合金； 時效
（ 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
