低成本细晶粒Mo2FeB2基金属陶瓷的制备及晶粒长大抑制机制研究

项目名称： 低成本细晶粒Mo2FeB2基金属陶瓷的制备及晶粒长大抑制机制研究

项目编号： No.51304124

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 矿业工程

项目作者： 余海洲

作者单位： 三峡大学

项目金额： 25万元

中文摘要： 反应硼化烧结的Mo2FeB2基金属陶瓷不含战略物质Co和贵重化合物WC且性能与常用硬质合金相当，因而作为工模具材料有着巨大的潜力和广阔的应用前景。本项目以廉价的FeB、FeMo、Fe粉等为原料，采用机械合金化的方法制备部分中间化合物，并用两步烧结法制备细晶粒Mo2FeB2基金属陶瓷。研究机械合金化过程中的物相变化规律；分析混合料的粉末粒度分布、粉末形貌、粉末缺陷、中间化合物的形成及主要烧结工艺参数对最终烧结体晶粒尺寸分布、显微组织、成分分布和力学性能的影响规律；重点研究两步法烧结过程中Mo2FeB2基金属陶瓷的固相骨架及孔隙的演变规律，细晶粒之间及大颗粒内部的界面取向特性，显微组织变化规律及影响因素；最终建立材料的成分、制备工艺、显微组织、界面微结构及性能的关系，并得到颗粒细化的机制。为在简单工艺条件下，制备结构合理、组织均匀、强韧性优良的细晶粒Mo2FeB2基金属陶瓷打下理论基础。

中文关键词： Mo2FeB2基金属陶瓷；两步烧结；相变；显微组织；力学性能

英文摘要： Mo2FeB2-based cermets by reaction boronizing sintering does not cotain the strategic Co and costly compounds of WC. In addtion, the mechanical properties compare favourably with the conventional WC-based hardmetals. Hence, Mo2FeB2-based cermets is a promising candidate for wear resistant applications. In this study, fined grain Mo2FeB2-based cermets was prepared by mechanical alloying and the two-step sintering with a low-cost raw material of MoFe, Fe and FeB powders. The phases variation during mechanical alloying was studied, and the effect of the powder particle size distribution, powder morphology, powder defect, formation of intermediate compound and the sintering process on the grain size distribution, microstructure, composition distribution and the mechanical properties were discussed. At the same time, we mainly investigated the evolutin of the solid skeleton and pore space, interface orientation relationship, evolution and influencing factors of microstructure during the two-step sintering. Based on these studies, the relationships between preparation technology, composition, microstructure and mechanical properties were established, and the mechanisms of grain refinement were obtained, which provided the theory foundation for the preparation of low-cost fined grain Mo2FeB2-based cermets with a better

英文关键词： Mo2FeB2-based cermets；two-step sintering；phase transformation；microstructure；mechanical properties