挤压过程中SiC颗粒对镁基复合材料基体动态再结晶行为的影响(英文)  

Effects of Reinforced Particles on Dynamic Recrystalliza- tion of Mg Base Alloys during Hot Extrusion

作　　者：常海[1] 王晓军[2] 胡小石[2] 王艳秋[3] 聂凯波[2] 吴昆[2] 

机构地区：[1]北京科技大学国家材料服役安全科学中心,北京100083 [2]哈尔滨工业大学,黑龙江哈尔滨150001 [3]哈尔滨工程大学,黑龙江哈尔滨150001

出　　处：《稀有金属材料与工程》2014年第8期1821-1825,共5页Rare Metal Materials and Engineering

基　　金：National Natural Science Foundation of China(51101043,50801017,51001036,51201006);China Post-doctor Science Foundation(2011M500238);the Fundamental Research Funds for the Central Universities(HIT NSRIF 201130)

摘　　要：主要研究了SiC颗粒增强镁基复合材料在不同挤压比、不同挤压温度下进行挤压后,SiC颗粒对镁合金基体中的动态再结晶现象影响。结果表明:挤压过程中颗粒周围产生了颗粒变形区(PDZ),并且颗粒变形区在低温挤压时以细小动态再结晶晶粒为主。颗粒促进动态再结晶晶粒形成的主要原因是颗粒周围较高的位错密度以及大的晶粒取向梯度。SiC颗粒对镁合金基体动态再结晶的影响主要有两方面:一方面,颗粒促进动态再结晶的形核以及生长,另一方面,当再结晶晶粒晶界碰到颗粒时,颗粒阻止了晶粒的继续长大。SiC particles reinforced Mg base composites were extruded at different temperatures and extrusion ratios. The effects of particles on dynamic recrystallization （DRX） of Mg matrix during hot extrusion were investigated. The results reveal that particle deformation zone （PDZ） is formed near a particle during hot deformation, and the PDZ is a characteristic of fine DRX grains in the composites extruded at lower temperatures. Particles promote DRX nucleation of Mg matrix during hot extrusion which may be attributed to high density dislocations and large orientation gradients in PDZ. Particles promote the growth of fine DRX grains until PDZ is consumed by DRX grains. On the contrary, at the stage when DRX grain boundaries contact with particles, particles pin grain boundaries and then retard grain growth.

关 键 词：镁基复合材料 动态再结晶 挤压 晶粒生长 

分 类 号：TB333[一般工业技术—材料科学与工程]