挤压对ZrB_2/6063Al复合材料组织及其摩擦磨损特性的影响  

Effects of Extrusion on Microstructure and Friction Wear Resistance in situ ZrB_2/6063Al Aluminum Matrix Composites

作　　者：李惠[1] 焦雷[2] 梅运柱 何忠秀 李永博 

机构地区：[1]江苏科技大学,江苏镇江212003 [2]江苏大学,江苏镇江212013

出　　处：《稀有金属材料与工程》2017年第10期3017-3022,共6页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(51605206);江苏省高校自然科学基金面上项目(14KJD430001)

摘　　要：以6063Al-(K_2ZrF_6+KBF_4)为反应体系,原位反应制备了ZrB_2/6063Al铝基复合材料,采用挤压方法对复合材料进行塑性加工。研究了挤压前后复合材料的微观组织变化,以及挤压工艺对复合材料摩擦磨损性能的影响。结果表明:铸态原位内生制得的复合材料,基体晶粒大小为30~50μm,ZrB_2颗粒呈规则的多边形,团聚现象严重。经过挤压加工之后,复合材料晶粒细化,大小为7~14μm,增强颗粒呈有圆边的多边形,分布均匀,尺寸为1~3μm,团聚改善。由于挤压后增强颗粒分布更加均匀,颗粒更加圆钝,使得摩擦后磨痕表面更加平整,各部分凹凸差异减小。摩擦系数随着载荷的增大而减小,载荷为12 N时摩擦系数最小为0.29,相比于原始铸锭复合材料的最小摩擦系数减小了32.4%。挤压后复合材料的磨损体积和磨损宽度均减小,耐磨性也得到了很大的提高。复合材料的磨损机制是以磨粒磨损为主,轻微粘着磨损为辅。In situ ZrB_2/6063 Al aluminum matrix composites were prepared by extrusion with 6063 Al-（K_2ZrF_6＋KBF_4） as the reaction system. The microstructure changes of the composites before and after extrusion were studied, and the influence of extrusion process on the friction and wear properties of the composites was also studied. The results show that for the composite materials prepared by in situ casting, the grain size of the matrix is 30~50 μm, and the ZrB_2 particles are regular polygons with serious agglomeration. After extrusion processing, the grain size of the composite is fine, between 7~14 μm, and the ZrB_2 particle size is uniform, between 1~3 μm, and agglomeration is improved. Because the particle size distribution is more uniform after extrusion, the particle is rounder and blunter, which makes the surface of the wear scar smoother, and the difference of the concave and convex of each part decreases. The friction coefficient decreases with the increasing of the loading. When the load is 12 N, the minimum friction coefficient is 0.29, which is reduced by 32.4% compared to that of the original ingot of composite materials. The wear volume and wear scar width decrease, and the wear resistance has been also greatly improved. The wear mechanism of the composites is mainly abrasive wear and slight adhesive wear.

关 键 词：ZrB2/6063Al复合材料 挤压 微观组织 摩擦磨损性能 

分 类 号：TB333[一般工业技术—材料科学与工程]