激光选区熔化碳化硅增强铝基复合材料的微观组织及拉伸性能研究  

Microstructure and Tensile Properties of SiC Reinforced Aluminum Matrix Composite Prepared by Selective Laser Melting

作　　者：邹田春 祝贺 陈敏英 梅思远 杨旭东[2] Zou Tianchun;Zhu He;Chen Minying;Mei Siyuan;Yang Xudong(College of Airworthiness,Civil Aviation University of China,Tianjin 300300,China;Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学适航学院,天津300300 [2]中国民航大学中欧航空工程师学院,天津300300

出　　处：《中国激光》2021年第10期225-233,共9页Chinese Journal of Lasers

基　　金：国家自然科学基金(51971242);中央高校基本科研业务费中国民航大学专项(3122020083);天津市研究生科研创新项目(2019YJSS079)。

摘　　要：采用机械混合法制备SiC/AlSi7Mg混合粉末,利用激光选区熔化(SLM)技术成形SiC/AlSi7Mg复合材料试样,研究复合材料的物相组成、微观组织和拉伸性能。结果表明:SiC/AlSi7Mg复合材料试样的相对密度最高能够达到99.2%;试样微观组织与典型SLM成形铝合金的组织相似,在铝基体中存在均匀分布的SiC及原位反应产生的Al_(4)SiC_(4)增强相,SiC与铝基体间形成了较强的界面结合。与铝合金相比,复合材料的强度明显提高,抗拉强度达到452 MPa,屈服强度达到280 MPa,但伸长率下降到4.5%;复合材料的主要断裂模式为脆性断裂。Objective Selective laser melting(SLM)is an important method to realize functional optimization design and manufacture lightweight metal parts.The parts fabricated by SLM possess have a fine microstructure and excellent mechanical properties due to the rapid cooling rate.Some typical metals,such as aluminum alloys,Ni alloys,and Ti alloys,have been manufactured successfully by SLM and are used widely in the aerospace,automobile,and marine industries.In recent years,aluminum matrix composites have attracted considerable attention because of the advantageous properties of the matrix and reinforcement materials.Compared to other reinforced particles,SiC particles are the most common ceramic reinforcement because of their easy availability,low cost,and high hardness.However,few studies have examined the relative density,microstructure,and properties of SLMed SiC/Al composites,particularly the tensile properties.In this study,5% SiC/AlSi7Mg composite specimens were prepared by SLM at different process parameters,and an almost entirely dense specimen was obtained.SiC particles and Al_(4)SiC_(4) phases formed during the in situ reaction were distributed uniformly throughout the aluminum matrix,and strong metallurgical bond existed at the interface.Such aluminum matrix composites posse high tensile strength and yield strength but low ductility compared with the SLMed aluminum alloy.The fracture mode of the SLMed composites was mainly brittle fracture.Methods The original powders used in this study were SiC powders and gas atomized AlSi7Mg powders.The mixed powders with 5% SiC powders were prepared using a V-type mixer.The SiC/AlSi7Mg composite specimens were then fabricated with SLM 125 equipment using different SLM process parameters in an argon atmosphere.Subsequently,the Archimedes method was used to measure the relative densities of the composite specimens.The microstructure of the SLMed composites was observed by optical microscopy and scanning electron microscopy after grinding,polishing,and etching in Keller reagen

关 键 词：激光技术 激光材料成形 激光选区熔化 铝基复合材料 微观组织 拉伸性能 

分 类 号：TG113.25[金属学及工艺—物理冶金]