(1. 中國(guó)礦業(yè)大學(xué)材料與物理學(xué)院，徐州 221116；
2. 浙江易鍛精密機(jī)械有限公司，寧波 315702；
3. 北京衛(wèi)星制造廠有限公司，北京 100094；
4. 江蘇大學(xué)材料科學(xué)與工程學(xué)院，鎮(zhèn)江 212013；
5. 中國(guó)礦業(yè)大學(xué)化工學(xué)院，徐州 221116)
摘 要: 本文利用原位同步輻射X射線衍射(SXRD)技術(shù)研究了一種亞穩(wěn)β型Ti-39Nb合金的非線彈性變形行為。結(jié)果表明：當(dāng)外加應(yīng)力超過(guò)60 MPa時(shí)，合金開(kāi)始出現(xiàn)非線彈性變形，此時(shí)合金發(fā)生應(yīng)力誘發(fā)馬氏體相變(SIMT)。因此，Ti-39Nb合金的非線彈性變形機(jī)制為SIMT。此外，加載過(guò)程中產(chǎn)生的馬氏體衍射峰只出現(xiàn)在同步輻射衍射環(huán)的特定角度，即與加載方向成26.5°。這是因?yàn)?w:sdt id="1515956098" sdttag="FX_MAT_ID80001458">晶向平行于加載方向的β相晶粒最先發(fā)生SIMT，且產(chǎn)生最大相變應(yīng)變的馬氏體變體優(yōu)先形成。
關(guān)鍵字: 鈦合金；應(yīng)力誘發(fā)馬氏體相變；同步輻射X射線衍射；非線彈性
（1. School of Materials Science and Physics, China University of
Mining and Technology, Xuzhou 221116, China;
2. Zhejiang Yiduan Precision Machinery Co., Ltd.,
Ningbo 315702, China;
3. Beijing Spacecraft Manufacturing Factory Co.,
Ltd., Beijing 100094, China;
4. School of Materials Science and Engineering,
Jiangsu University, Zhenjiang 212013, China;
5. School of Chemical Engineering and Technology,
China University of Mining and Technology,Xuzhou 221116, China）
Abstract:In this paper, the nonlinear elastic deformation behavior of a metastable β-type Ti-39Nb alloy was studied by in situ synchrotron X-ray diffraction (SXRD) technique. The results indicate that the onset of the nonlinear elastic deformation appears at an applied stress higher than 60 MPa, and stress-induced martensitic transformation (SIMT) occurs simultaneously. As a result, the nonlinear elastic deformation behavior of the Ti-39Nb alloy could be attributed to the SIMT mechanism. Besides, the diffraction peaks of martensite appeared at specific azimuth angles of the SXRD rings initially, i.e., 26.5° from the loading direction. This is because that SIMT will firstly occur in the β grains with
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