PRMMCs高温挤压与室温力学性能研究

研究了ＳｉＣ含量及其分布、温度与变形速度等因素对ＳｉＣ颗粒增强金属基复合材料（ＰＲＭＭＣｓ）高温挤压与室温力学性能的影响．结果表明：挤压力随行程呈阶段性变化特征，材料致密度影响镦挤填充阶段变形，温度与挤压速度对挤压力影响较大；挤压变形可使材料的基体连续，增强体ＳｉＣ颗粒分布均匀，梯度层间界面消失；材料的真实应力－应变曲线符合抛物线规律；ＳｉＣ含量对这类材料的力学性能有较大影响，ＳｉＣ分布方式对材料抗拉强度和塑性的影响要比对刚度的影响大．

Hot Extrusion of Metal Matrix Composites Reinforced by SiC Particles and Mechanical Properties of the Materials at Room Temperature

A study is made to determine how the SiC content and distribution, temperature and deformation rate could influence the hot extrusion process of metal matrix composites reinforced by SiC particles (PRMMCs). The mechanical properties of the materials at room temperature are also determined. Three main conclusions can be drawn from the results:(a) For a given extruding load and stroke, the specific density of the materials could affect the deformation of the upsetting stage while the temperature and deformation rate could influence the extruding force. (b) Extrusion could enhance the continuity of matrix, uniformity of SiC particle distribution and elimination of gradient boundary layers. (c) The true stress strain curves could conform to the parabolic law. SiC content could have great influence on the mechanical properties of the materials and SiC particle distribution could have a pronounced effect on the tensile strength and plasticity of the materials.