(北京航空材料研究院, 北京 100095)
摘 要: 研究了Ti-47.5Al-2Cr-2Nb合金中添加微量硼對合金760 ℃, 275 MPa持久性能的影響。結果表明：在同樣的熱處理制度下，添加0.2%（摩爾分數）硼能顯著提高合金的持久壽命；尤其對于全片組織， 其持久壽命由150.0 h提高到460.5 h，這主要歸因于，添加微量元素硼抑制了連續(xù)冷卻轉變過程中魏氏片層束和羽毛狀片層束在片層晶粒內的形成，從而提高了全片層組織的熱穩(wěn)定性。
關鍵字: TiAl合金； 硼； 持久性能； 組織穩(wěn)定性
creep rupture property of TiAl alloy
（ Beijing Institute of Aeronautical Materials, Beijing 100095, China）
Abstract: The effect of minor boron addition on creep rupture property of Ti-47.5Al-2Cr-2Nb alloy under 760 ℃, 275 MPa condition was investigated. The addition of 0.2%B into the alloy can effectively improve the creep rupture property, especially for the fully lamellar microstructure, the creep rupture life is prolonged from 150 h to 460.5 h. The main reason is that minor boron addition suppresses the formation of Widm-fstatten lamellar colonies and feathery lamellar colonies in lamellar grains during continuous cooling transformation, and then improves the thermal stability of the fully lamellar microstructure.
Key words: TiAl alloy; boron; creep rupture life; microstructure stability
