The Effect Of Y And Hot Extrusion On The Microstructure And Properties Of Zl101 Alloy

As a traditional material,aluminum alloy has been widely used in many manufacturing industries.However,aluminum alloys produced by conventional methods of smelting and casting have coarse and irregularly distributed internal crystal structures.Ingot itself lower strength,poor plasticity.With the increasing demand of people,aluminum alloy can not fully meet people's needs.So rare earth Y were used to prepare aluminum alloy.In this paper,we research the the microstructure and properties of ZL101 alloy with different rare earth Y.It was found that addition of 0.2 wt.%Y causes the refined microstructure?including primary?-Al and eutectic Si?and reduced secondary dendrite arm spacing of?-Al matrix?14.59?m?.The eutectic silicon and Fe phases in the alloy chanced from long needle to short rod,Eutectic Si phase staggered two organizations and organizations evenly distributed.In order to have best the mechanical properties,this article using the extrusion ratio of 4:1 abrasive hot extrusion at 460?,it is found that the alloy after hot extrusion,the mechanical properties have significantly improved,especially the elongation has been significantly improved.when compared with the cast alloy,the rare earth's addition make the alloy after hot extrusion get better mechanical properties,Compared to the ZL101 alloy,the ultimate tensile strength,elongation and hardness of the alloy after hot extrude with 0.2wt.%Y were increased by 37%,21.3%and 400%,respectively.Compared the extruded ZL101 matrix and the alloy containing 0.2wt%Y,the evolution process and mechanism of the two alloys were studied,and the changes of mechanical properties before and after heat treatment were also discussed.Thereby determining the best solution temperature and solution time.The solution treatment causes the eutectic Si to spheroidize and the Al₂Cu dissolve to alloy,make the iron phase skeleton clear.it is found that the matrix alloy after hot extrusion to achieve the best organization at a temperature of about 525?and keep 1.5h,the eutectic Si phase presents a spherical shape and with the highest spheroidization rate,only a small part of the coarse silicon presents a lump due to its poor solubility.The alloy with rare earth achieve best organization when the solution time is 1 hour.When compared the microstructures of extruded alloy and un-extruded alloy with heat treatment,it found that the extruded alloy with heat treatment have a better spheroidization rate of the silicon phase,the aspect ratio is closer to 1,so the extruded alloy have much better mechanical properties.The improvement of the mechanical properties of the alloy shows that extrusion is more favorable for heat treatment.Compared to the extruded ZL101 alloy,the ultimate tensile strength,elongation of the alloy with heat treatment were increased by 24.57%,37.27%and 27%,In addition,it is found that the tearing edge of the extruded alloy after heat treatment is thicker than the alloy without heat treatment.The tensile strength of the alloy is much improved compared with the extruded.Therefore,the extruded alloy with heat treatment have significant ductile fracture,the plasticity has been greatly improved.Friction and wear tests were carried out on the as-cast alloy and the as-extruded alloy,the as-extruded alloy with rare earth and the extruded alloy after heat treatment respectively,according to the experimental results,the wear amount of the specimen increases with the increase of the normal load,however,the friction coefficient decreases with the increase of the load.Extruded alloys with rare earth and heat treatment has the least wear whatever load,it indicated that the material after heat treatment had better wear resistance.The wear mechanism of the sample under low load is mainly abrasive wear and oxidation wear,plastic deformation can be observed when the load reaches.Under high load,the as-cast ZL101 alloy shows severe plastic deformation and plastic deformation and peel wear as the main wear mechanism.When the rare earth extruded alloy is added,the wear resistance of the alloy increases.The degree of flaking is reduced,the alloy after heat treatment is still smooth and smooth under high load,there is no obvious crack phenomenon,so it can be proved that the alloy after heat treatment has better wear resistance.