核壳网络结构钛氧、钛氮合金显微组织演变及力学行为研究

项目名称： 核壳网络结构钛氧、钛氮合金显微组织演变及力学行为研究

项目编号： No.51271152

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 一般工业技术

项目作者： 张于胜

作者单位： 西北有色金属研究院

项目金额： 80万元

中文摘要： 由于高的界面体积百分数，纳米晶粒可视为由核（晶内）与壳（晶界）两部分构成，其中壳的强化作用显著，核却无法提供位错存储的足够空间，导致纳米晶材料强度极高而塑性极差。如果在粗晶内构造核壳结构，则有望综合纳米晶与粗晶材料的优势，在金属材料中实现强度与塑性的良好匹配。本项目通过渗氧、渗氮处理，利用氧、氮在微米尺度钛粉颗粒表里浓度不同构建核壳结构，然后烧结固化，得到核壳网络结构钛氧、钛氮合金，并通过热处理调整其结构和性能。研究氧、氮在钛基体中的扩散行为及与相变的相互作用机制对核壳网络结构形成过程的影响规律，揭示此结构的形成机理；研究核壳网络结构材料高温下的显微组织演变规律及与力学行为依赖关系，揭示其强化机理与塑性变形机制；完成变形过程的有限元模拟，并建立力学模型。此项工作不仅为发展高性能工程结构材料开辟了新途径，而且对材料制备技术的发展具有积极的促进作用。

中文关键词： 核壳结构；固溶强化；力学行为；高温强度；耐磨性

英文摘要： A nanocrystalline grain can be regarded to be composed of two parts: the core (grain interior) and the shell (grain boundary region) due to its high boundary volume percent. Because of significant strengthening of the shells and absence of space for dislocation motion in gain interiors, the nanocrytalline materials possess high strength and low ductility. It is suggested that the optimized combination of high strength and moderate plasticity can be obtained in case a core-shell structure is constructed in a microcrystalline grain. In this work, core-shell network structural bulk Ti alloys were successfully synthesized by means of a unique methodology combining nitriding of powders where the core-shell structure was engineered in the light of different solid solution level of nitrogen in particle boundary and particle inner and subsequent SPS treatment. Then their microstructure and mechanical properties can be tailored by heat treatment. We plan to elucidate the formation mechanism of the novel structure by studying the role of the diffusion behavior of O and N in Ti matrix and its interaction with phase transformation in microstructure evolution during sintering; study microstructure evolution in high temperature and its dependent relationship with mechanical behaviors to clarify the strengthening and deformati

英文关键词： Core-shell structure；Solid solution strengthening；Mechanical performances；High temperature；Wear resistance