摘要
纳米复合材料是目前的研究热点,采用热压烧结法制备了纳米Al2O3颗粒强化铜基复合材料。采用阿基米德排水法测试了复合材料的致密度,采用硬度计测试其硬度,采用表面三维形貌仪测量其磨损体积并观察磨痕的三维形貌;采用摩擦磨损试验机研究了复合材料的摩擦磨损性能并分析其磨损机制;采用扫描电镜及能谱仪观察复合材料磨损前后的表面形貌、分析磨痕的化学成分;研究了工艺参数及Al2O3含量对复合材料性能的影响。结果表明:复合材料的最佳热压制备工艺为热压温度900℃,热压压力27.5 MPa,保温时间2 h,所得铜基复合材料的相对致密度达99.03%;随Al2O3含量增加,复合材料的硬度增加,耐磨性先升高后降低;Al2O3含量为2%时,复合材料磨损量最少,相对耐磨性为3.13,硬度较纯铜提高了35.5%;随Al2O3含量的增加,铜基复合材料的磨损机制从以黏着磨损为主转变为以磨粒磨损为主。
Copper matrix composites reinforced by nanoscale alumina were prepared by hot-pressed sintering so as to increase processing controllability and reduce cost. The relative density of as-fabricated Cu-matrix composites was determined by Archimede's water replacement method,and their microhardness was measured with a microhardness meter. Moreover,a friction and wear tester was performed to evaluate the friction and wear behavior of as-fabricated Cu-matrix composites,and the effects of processing parameters and alumina content on the friction and wear behavior were investigated. In the meantime,the three-dimensional( 3D) wear scar morphology and wear volume loss of the Cu-matrix composites were analyzed with a 3D surface profilometer. The morphology of the Cu-matrix composites before and after friction and wear tests were observed with a scanning electron microscope,and the composition of the wear scar was determined with an energy dispersive spectrometer. Furthermore,the wear mechanisms of the Cu-matrix composites were discussed. As the results,the optimized sintering processes for fabricating Cu-matrix composites were suggested as hot-pressing temperature of 900 ℃,hot-pres-sing pressure of 24. 5 MPa,and temperature-holding time of 2 h.Cu-matrix composite obtained under the optimized processing parameters had a relative density of as much as 99. 03%. Besides,the microhardness and wear resistance of Cu-matrix composites initially rose but declined later with increasing content of nanoscale Al2O3,and the composite containing 2% nano-Al2O3( mass fraction) had the best wear resistance. Moreover,along with the increase of nano-Al2O3content,the wear mechanisms of Cu-matrix composites were transferred from adhesion wear to abrasive wear.
出处
《材料保护》
CAS
CSCD
北大核心
2014年第1期21-24,8,共4页
Materials Protection
基金
淮安市科技支撑计划(HAG2011004)资助
