Al-Mg系自生纤维增强铝基复合材料组织与性能

Investigation on Fabricating Technology of In-Situ Fiber Reinforced Metal Matrix Composites

摘要:

为解决金属基复合材料中外加增强体与基体间异质界面对材料性能带来的不利影响，提出一种基于粉末冶金技术的原位复合新工艺，并制备出自生金属间化合物纤维增强铝基复合材料。研究结果表明，原位生成的金属间化合物纤维均匀分布在基体中，并平行于材料制备时的挤出方向；原位复合材料的增强效果明显，屈服强度比外加复合材料和基体分别高出28％和95．7％，断裂强度则相应提高了20．6％和88．5％；原位复合材料的强化机制主要是基体和增强体间界面结合良好，既能发挥基体的塑韧性，又能有效发挥自生增强体的强度优势，材料的断裂机制为自生纤维脆性断裂和劈裂。本研究同时表明，此方法工艺简单，成本低廉，且效率高，容易实现产业化。

Abstract:

To avoid the disadvantages resulting from the interface between matrix and reinforcement for metal matrix composites (MMCs), a novel in-situ synthesizing technology, based on powder metallurgy, is presented in this paper. A kind of aluminum matrix composite reinforced by in-situ intermetallic compound fiber was prepared. The results showed that in-situ fiber was distributed uniformly in matrix, parallel to the extrusion direction. Yield strength of in-situ MMCs is 28% and 95.7% higher, respectively than those of ex-situ MMCs and matrix aluminum, and fracture strength is increased by 20.6% and 88.5% correspondingly. The strengthening mechanism of in-situ MMCs is that the excellent interface bonding between the matrix and the reinforcement. The matrix exhibits its strong strength, and the reinforcement exhibits its strong strength. The fracture mechanism of in-situ MMCs is the brittle fracture and cleavage crack of fibers.