研究了近α型Ti60钛合金自β单相区连续冷却至室温过程的相转变规律,冷却速率控制在80℃.s-1至0.1℃.s-1范围内.采用膨胀法原位分析了冷却过程中β→α '马氏体转变和β→α扩散型转变的起止温度及动力学特征,并观察对比了不同冷却速率下显微组织特征.在超过50℃·s-1的快冷条件下,原始β目约在910℃快速转变为细小针状α'马氏体,并且没有残余.在马氏体内部发现大量的位错以及(1011)层错,证明转变过程伴随有晶格畸变.在5℃·s-1的慢冷条件下,a相在β晶内和晶界都有形核,而在低于1℃·s-1时,α相仅在晶界形核,透射电镜下发现a片层间仍残留少量β相,而在片层内部α相发生了有序转变,形成α2相.冷却速率决定了连续冷却过程中同素异构的相转变机制以及生成相的内部结构.
参考文献
| [1] | Gil FJ.;Manero JM.;Planell JA.;Ginebra MP. .Formation of alpha-Widmanstatten structure: effects of grain size and cooling rate on the Widmanstatten morphologies and on the mechanical properties in Ti6Al4V alloy[J].Journal of Alloys and Compounds: An Interdisciplinary Journal of Materials Science and Solid-state Chemistry and Physics,2001(1/2):142-152. |
| [2] | Zhang XD.;Bonniwell P.;Fraser HL.;Baeslack WA.;Evans DJ.;Ginter T. Bayha T.;Cornell B. .Effect of heat treatment and silicon addition on the microstructure development of Ti-6Al-2Cr-2Mo-2Sn-2Zr alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2003(1/2):210-226. |
| [3] | Ohmori Y.;Nakai K.;Kobayashi S.;Ogo T. .Effects of omega-phase precipitation on beta -> alpha, alpha '' transformations in a metastable beta titanium alloy[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2001(1/2):182-188. |
| [4] | Matsumoto, H.;Yoneda, H.;Sato, K.;Kurosu, S.;Maire, E.;Fabregue, D.;Konno, T.J.;Chiba, A. .Room-temperature ductility of Ti-6Al-4V alloy with α' martensite microstructure[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2011(3):1512-1520. |
| [5] | Elmer JW;Palmer TA;Babu SS;Specht ED .In situ observations of lattice expansion and transformation rates of alpha and beta phases in Ti-6Al-4V[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2005(1/2):104-113. |
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