粉末冶金γ-TiAl基合金放电等离子烧结机理研究

项目名称： 粉末冶金γ-TiAl基合金放电等离子烧结机理研究

项目编号： No.51301204

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 王岩

作者单位： 中南大学

项目金额： 24万元

中文摘要： γ-TiAl基合金兼具金属和陶瓷的优点，是一种最具竞争力和发展前景的航空航天用新型材料。放电等离子烧结技术融等离子活化烧结、热压、电阻加热于一体，已成功应用于γ-TiAl基合金的粉末冶金制备并获得了高致密度和细晶的烧结体，然而目前有关γ-TiAl基合金放电等离子烧结的致密化过程及其机理尚不明确。本项目拟以TiAl-Nb合金体系为对象，旨在研究不同粉末状态的TiAl-Nb基合金在放电等离子烧结过程中的相转变规律，探讨多场耦合作用下TiAl-Nb基合金的放电等离子烧结致密化机理，获得弱导电B粉末颗粒的添加对TiAl-Nb基合金放电等离子烧结颈形成与长大的影响及其作用机制，以期实现粉末原料本征特征、烧结制度、微观组织及典型性能的协同性控制。本项目的开展不仅对丰富放电等离子烧结理论具有重要的学术价值和理论意义，而且对实现γ-TiAl基合金性能瓶颈的突破、推动其工程化应用的进程具有显著的现实意义。

中文关键词： γ-TiAl基合金；放电等离子烧结；相转变；微观组织；烧结机理

英文摘要： Owning the advantages of both metal and ceramics, γ-TiAl based alloys are considered as the most competitive and developing materials used in the field of aerospace. With combination of plasma activated sintering, hot pressing and resistance heating, spark plasma sintering (SPS) technique has been successfully applied to the fabrication of powder metallurgy γ-TiAl based alloys, and sintered bodies with high densities as well as fine grains have already been gained. However, the densification course of γ-TiAl based alloys during SPS as well as its sintered mechanisms is still unknown up to now. In this project, TiAl-Nb alloy system is going to be selected as the object of study. The phase transformation regularity during SPS of TiAl-Nb based alloys with different initial powder states will be investigated. The sintered densification mechanisms of TiAl-Nb based alloys under the condition of multi-field coupling will be discussed. The effect of the boron powder additions with weak conductivity to the formation and growth of sintered necks during SPS of TiAl-Nb based alloys as well as its mechanisms will be explored. Coordination control of intrinsic characteristic of raw powder, SPS condition, microstructure and typical service performance is being expected to realize. The research results would not only provide th

英文关键词： Gamma TiAl based alloy；spark plasma sintering；phase transformation；microstructure；sintering mechanism