Forming Technics And Microstructure Research Of Bi-metal Composites Based On Squeeze Casting

Metal matrix composites(MMCs) are based on metal alloy with the second phase of high-strength as their reinforcements.There are many merits of MMCs, such as high specific strength,high modulus,wear resistance,heat resistance, electrical conductivity,thermal conductivity,non-moisture absorption,anti-radiation, low heat expansion coefficient.The conventional metal materials have been replaced by advanced composites which are used in aerospace,aviation,automotive industry,electronic industry and other fields.The system of modern composites is composed of MMCs,polymer matrix composites,carbon/carbon composites, ceramic matrix composites and nano-composites.Currently,Aluminum matrix composites is the most widely used in MMCs.With the development of ways for preparation,its structure and nature are designed.At the same time,the cost has greatly lowered with the use of low-cost reinforcement phase.Squeeze casting is a rough forming process,which combines casting with forging.High quality parts are got which have exquisite microstructure,good physics performance and smooth surface,for the liquid metal is solidificated under pressure.Besides this technics is applicabled on both casting alloys and forging alloys,and it isn't restricted to alloy's trademark.The reasearch on squeeze casting is relatively few in our country.But the factors which affect the quality of the squeeze casting parts are so many,and there are interactions among the factors,so qualitative analysis can hardly help the practical manufacture.Combining with the characteristics of squeeze casting,extrusive technology is used to compound solid metal and liquid metal into composites in this paper.Better performance of composites is embodied by the technics.During it,by changing the parameters,the interface structure and organizational characteristics of composites have been studied.Besides,the influence on their interface structures is researched by comparing the setting of different parameters.A group of relatively good paramenters are got,which can optimize performance of the composites.Many results have been obtained in the paper:under the guidance of Squeeze Casting theory,the organization of the ZA4-1/ZL102 composites is more meticulous by the rational control of its parameters.A new type of composits is obtained by that Aluminum Alloy's tissue breaks the shackles of its atom into zinc alloy's organization,and the bi-metallic compound is achieved under the squeeze casting technics.