The Impact Of Rare Earth On Microstructure And Properties Of Za43 Alloy

The zinc alloy is the non-ferrous metal that it was added proper aluminum, copper and other trace elements as Mg,Mn,Si,B,Rare Earth(RE) on the basis of Zinc. The alloy is a supersaturated solid solution and the function of solution strengthening is obvious .The high aluminum zinc alloy is the new cast non-ferrous alloy developing almost 20 years fastly.This alloy is a ideal substitute of copper for its cheapness and good at mechanical,antiwear properties .Its main character is make antifriction parts instead of copper. That substitute Zinc for Copper is very important in our country's resource and policy. It will be a new pattern of using non-ferrous alloy in the world. However, presently,ZA43 alloy of researching is still exist some problems just like lower strength and hardness,antiwear is not good which is not satisfy some special usage properties of alloy.In the paper, chemical segregation,microstructure,the being way of rare earth in alloy,mechanical and antiwear properties of the alloy was researched by adding rare earth to modifying ZA43 alloy. The results show that:1. Aluminum content is 40.70%,41.13% in feeding and head of ZA43 cast sample respectively and 41.22%,41.26% which was added rare earth by 0.15%.It indicates that the ZA43 what was modified by adding proper RE can efficiently resist the growth of a dendrite crystal,optimize microstructure and refine grains.2. The being way of mixture rare earth by 0.15% in cast structure of modification ZA43 alloy was studied through SEM-EPMA and structure of every phase in sample was analyzed. It is found that the rare earth distributes at the grain boundary of alloy and exists with solution and rare earth compound. There is no RE in center and rim of branch grain but lower content at the rim of a phase and no inηphase .It indicates that it will diminish chemical segregation and refine structure of modification alloy with adding modification reasonably.3. Mechanical properties experiment reveal that hardness,tensile strength and coefficient of elongation of ZA43 alloy was improved while rare earth modification is the midst of 0.05-0.15% and the synthetic properties is the best by 0.15%.But, when it is beyond 0.15%, the tensile strength shows trend of reducing as the content of the rare earth increasing. With the content of rare earth increasing, wear of ZA43 alloy reducing. So does the friction parameterμ.when rare earth is beyond 0.05%,the properties of friction and wear of the alloy is better than ZQSn6-6-3.So, The alloy can instead of copper alloy absolutely as a good substitute and will obtain largely economic and social efficiency using the substitute zinc for copper to making antiwear parts.