陶瓷颗粒增强钢基表层复合材料的界面连续性控制

项目名称： 陶瓷颗粒增强钢基表层复合材料的界面连续性控制

项目编号： No.50871048

项目类型： 面上项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 蒋业华

作者单位： 昆明理工大学

项目金额： 32万元

中文摘要： 项目以高温复合磨损工况下使用的零部件为应用背景，旨在解决陶瓷颗粒增强金属基表层复合材料在高温下使用寿命不高的共性问题。项目对碳化钨与基体间界面反应的热力学进行了计算，采用差热分析法对界面形成进行模拟研究，探讨了界面反应机制；采用分区域测试的方法，选取W元素作为衡量界面连续性的考察标准，考察C、Fe、Cr、Ni等元素在宏观界面和微观界面含量的变化速率，研究了复合材料的热物理性能、抗高温氧化性能以及热疲劳裂纹萌生、扩展的方式、过程, 以及微观界面控制、宏观界面控制与热疲劳裂纹萌生扩展间的联系，提出了控制界面的方法。研究得出以下主要结果：（1）界面为反应、扩散型界面；（2）C会抑制碳化钨颗粒在基体中溶解，而Cr反之；（3）获得各元素对界面连续性的影响规律，Ni粉是提高界面连续性最适合的合金添加粉末，钨铁粉次之；（4）通过加入钨铁粉和Ni粉可有效控制表层复合材料的界面；（5）获得不同合金元素对热疲劳裂纹扩展速率的影响规律，其验证了界面连续性控制方法的可行性；（6）裂纹倾向于在靠近过渡区的WC颗粒处萌生。项目研究结果对充实陶瓷颗粒增强钢基表层复合材料中界面控制理论具有重要意义。

中文关键词： 复合材料界面；界面控制；钢基表层复合材料；热疲劳；裂纹

英文摘要： This project focused on the key issue of ceramic particle reinforced metal matrix surface composites whose thermal fatigue performance was not satisfactory in industrial application background of high temperature and complex wear service. The interface reaction mechanisms between WC particles and the matrix were discussed, through thermodynamic calculation and simulating by differential thermal analysis. The distribution of W in WC/matrix interface and composite/substrate interface was selected as the criterion for interface succession, the content variation of C, Fe, Cr and Ni in these interfaces, the characteristics of the composite layer, such as thermal physical properties, high temperature oxidation resistance and thermal fatigue cracking and propagating, were measured and observed, so the control method in interface succession was built, based on the connection between the interface succession control and propagation of thermal fatigue crack. The main research results include: (1) The interfaces are reaction and diffusion typed; (2) Increase in C content can restrain the decomposition of WC particles, but it does not work for Cr; (3) The influence of alloying elements on the interface succession is concluded, in which Ni addition is most effective, followed by W; (4) Ni or W addition can improve the interface succession effectively; (5) Effect of alloying elements addition on thermal fatigue crack propagation rate reflects the validity of interface succession control method; (6) The cracks tend to arise around the WC particles nearby the transition region of the composite/substrate interface. The project results are of great significance in development of the interface control theory of ceramic particle reinforced metal matrix composites.

英文关键词： composites interface; interface control; steel matrix surface composite; thermal fatigue; crack