高压凝固下γ-TiAl合金组织演变及热稳定性研究

项目名称： 高压凝固下γ-TiAl合金组织演变及热稳定性研究

项目编号： No.51501100

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 一般工业技术

项目作者： 朱冬冬

作者单位： 衢州学院

项目金额： 20万元

中文摘要： 在航空航天领域，γ-TiAl合金是目前最具发展潜力的一种轻质高温结构材料，但合金的室温塑性低和断裂韧性差极大的限制了合金的应用。以往的研究局限于通过热等静压、快速凝固方式等方式来提高合金塑性，而忽略了高压对γ-TiAl基合金偏析抑制的重要作用，对γ-TiAl基合金在高压下的相及组织演变规律缺乏基本认识，严重制约了γ-TiAl基合金的进一步发展。对此，本项目以γ-TiAl基合金在高压条件下的凝固行为为对象展开研究，揭示高压对γ-TiAl合金相选择机制、组织演变规律，分析高压下的包晶反应过程及偏析机制，建立热处理工艺和高压凝固组织之间的内在联系，因此本项目的研究对减少TiAl基合金中的偏析，提高TiAl基合金的力学性能，进一步推动TiAl基合金的工程化应用具有指导意义。

中文关键词： 钛铝金属间化合物；高压凝固；组织演变；热稳定性

英文摘要： γ-TiAl alloy is one of the most potential light-weight high temperature structure materials in the field of aerospace engineering. However, γ-TiAl alloy shows low room-temperature ductility and fracture toughness, which contrains its application. Conventional studies focused on improving the ductility by HIP and rapid solidification, the significant influence of high pressure on improving ductility and inhibiting segregation by high pressure solidification has been ignored, which largely restricted the further development of γ-TiAl alloy. For this reason, this current subject will study γ-TiAl alloy solidified under high pressure to clarify the evolution of microstructures and the phase selection mechanism. Further, the process of peritectic reaction and the segregate mechanism will be built by studying the influence of the microstructures. The inter-relationship between the heat treatment and high pressure solidified microstructures will also be built. Therefore, the study of this subject can decrease the segregation and improve the mechanical properties, which will have directive significance for the engineering of γ-TiAl alloy.

英文关键词： TiAl Intermetallics;High Pressure Solidification;Phase Transformation;Thermal Stability