Study On The Preparation Of SiC Reinforced Al Matrix Composites By Microwave Sintering

SiC reinforced aluminum matrix composites enjoy advantages,such as high temperature resistance,wear resistance,corrosion resistance,fatigue resistance,high specific strength,good stiffness ratio,dimensional stability,light weight,etc.Thus,such composites are widely used in areas of aviation,aerospace,electronics,electrical appliances,automobile industry.Microwave sintering technology have such advantages as high efficiency,energy saving,environmental protection,so as to meet the requirement of modern industry clean production.In addition,microwave sintering technology owns characteristic of activated sintering,which is benefited for obtaining excellent microstructure,especially suitable for powder metallurgy sintering.Therefore,this paper mainly studies the effect of different microwave sintering on the properties of SiC reinforced aluminum matrix composites.This paper adopts planetary ball milling to prepare SiC/Al composite powder that is sintered by microwave atmospheric pressure and microwave hot pressure.SiC/Al composite materials are successfully prepared.Main research works are as following:The research on technology of preparation of SiC/Al composites by microwave atmospheric pressure sintering.The influence of such technological parameter as SiC content,compact pressure,sintering temperature and holding time on microstructure of SiC/Al composites and mechanical property is studied by single factor method.The research shows that under the condition--the technological parameters of SiC content is 15Vol%,compact pressure is 250MPa,sintering temperature is 770?,and holding time is 5min--density of SiC/Al composites is 96.14%,the distribution of SiC particles in Al matrix is relatively uniform,the interface combining effect is good and hardness also reaches the maximum value--130.2Hv.The process parameters of microwave atmospheric pressure sintering are optimized by the response surface method.The optimized results of combination single factor experiment and response surface method obtain the most optimal process parameters:(1)When the SiC content is lOVol%,compacting pressure is 268.72MPa,and sintering temperature is 774.71?,the density of SiC/Al composite material is 97.24%.(2)When the SiC content is 15.58 Vol%,compacting pressure is 255.53 MPa,and the sintering temperature is 768.29?,the hardness of the SiC/Al composite material is 130.39Hv.The research on technology of preparation of SiC/Al composites by microwave hot pressing sintering.Preparation of SiC/Al composites by microwave hot pressing sintering is realized by optimizing Microwave hot pressing furnace,thermal insulation structure and furnace mould.Influence factors of microwave hot pressing sintering technology are discussed systematically.Meanwhile,the influence of different microwave hot pressing sintering technology on properties of SiC/Al composites is studied.The influence of hot pressing temperature and hot pressing pressure on density,hardness,microstructure and phase of SiC/Al composites is mainly studied.Microwave atmospheric pressure microwave sintering process and microwave hot pressing sintering process are compared.The result shows that both approaches can prepare SiC/Al composites with good properties.However,SiC/Al composites by microwave hot pressing preparation enjoys more superiority on density,hardness and microstructure.