SiC颗粒增强铝合金基梯度复合材料的制备与压缩性能研究

STUDY OF FABRICATION AND COMPRESSIVE PERFORMANCE OF ALUMINIUM ALLOY MATRIX GRADIENT COMPOSITES REINFORCED WITH SiC PARTICLES

把梯度功能材料（ＦＧＭ）的设计思想用于金属基复合材料（ＭＭＣｓ）的开发之中，成功地制备出了ＳｉＣ颗粒增强铝合金基梯度复合材料。对该材料的组织结构和高温压缩性能进行了实验研究。结果表明：采用复压烧结粉末冶金工艺能提高材料致密度，消除梯度层间界面；高温下材料的真实应力－应变曲线可分为初始硬化和逐渐软化两个阶段，材料强度主要由基体决定；高温下变形时，材料梯度层间界面无相对滑动，变形情况与梯度分布方式有关。

The design idea of Functionally Gradient Materials(FGM) is adopted to develop Metal Matrix Composites(MMCs) and the aluminum alloy matrix gradient composites reinforced with SiC particles are fabricated successfully. Experimental study is made on microscopic structure and compressive performance of the materials at high temperature. The results show that specific density of the materials can be increased and the gradient boundary layers can be eliminated by means of the second compressing and resintering power metallurgy technique, the true stress strain curves of the materials at the high temperature can be divided into two parts, strain hardening and strain weakening, the matrix has influence on strength at the high temperature but not the particles, relatively sliding motion is not found in the gradient boundary layers of the materials, and the deformation is related to the ways of gradient distribution of the materials.