Effect Of AlTi5B On Microstructure And Properties Of Zn-Al4.2-Cu0.5 Alloy

The characteristics of zinc alloys are cheap,easy molding,melting of low energy consumption,little environmental pollution,so it has strong market competitiveness.Therefore,zinc and zinc alloy can take the place of copper alloy used for decoration,furniture,hardware field.Zinc alloy used in this paper is based on the requirements of the production process of the jewelry industry,firstly use AlTisB master alloy to refine Zn-Al4.2-Cu0.5 alloy's grains,and then with different heat treatment process,to study the microstructure and mechanical properties of Zn-Al4.2-Cu0.5 alloy,the purpose is to improve its cast plastic,to meet the requirements of shaping.The experiment mainly uses the metallographic analysis,tensile test,scanning electron microscopy;finally the results of the study show that,?1?AlTisB master alloys can effectively refine the Zn-Al 4.2-Cu0.5 alloy's grains,and with different content of AlTisB,it has different refining effect.In the melting alloy,AlTisB master alloy is decomposed into TiAl3 and TiB2 phase,then they work together to refine grains;but when the AlTi₅B alloy is too much,the grains of the alloy are begin to grow.The tensile strength of Zn-Al4.2-Cu0.5 alloy decreased first and then increased,while the elongation is increased first and then decreased.AlTisB master alloy suitable addition amount is 0.56%?0.94%.When the addition of AlTisB is about 0.94%,the micstructure of Zn-Al4.2-Cu0.5 alloy is fine and uniform.?2?Use the grain refinement and homogenization heat treatment together can effectively improve the Zn-Al 4.2-Cu0.5 alloy's plastic.After Zn-Al 4.2-Cu0.5 alloy with different heat treatment process,found the better heat treatment is heating at 300 ?,holding for 3h,with furnace cooling.After heat treatment,the microstructure of the Zn-Al4.2-Cu0.5 alloy is mainly composed of equiaxed ??Zn?and granular eutectoid phase??+??and a small amount of the second phase.Hardness of Zn-A14.2-Cu0.5 alloy is 42.248HV,tensile strength is 188MPa,elongation is 10.8%.?3?Zn-Al 5.2 alloy further validate experiments show that grain refinement plus homogenization heat treatment can improve the plasticity of as cast zinc alloy.After grain refinement and homogenization heat treatment,the eutctoid of Zn-Al 5.2 alloy from lamella transformed into granular,not only the tensile strength increased,the elongation is improved,the elongation increased by 106%.