| With the development of zinc aluminum alloy,it is considered to be suitable for the mechanical parts such as bearing,bearing,slide and other mechanical parts because of its excellent mechanical properties,wear resistance and damping properties,and it is widely used because of its low cost of raw materials and production.However,most domestic and foreign scholars focus on the zinc-aluminum alloys with Zn content higher than 50%,only a few scholars study aluminum zinc alloy with zinc content lower than 50%.Compared with zinc-aluminum alloys,aluminum zinc alloy has the advantage of light weight because of its low content of zinc and also has good damping performance.To better and more investigate the microstructure,mechanical properties and damping capacity of aluminum zinc alloy,this paper has studied aluminum zinc alloy.In this paper,to obtain a lightweight aluminum zinc alloy with excellent damping property and good mechanical properties,firstly,25wt.%(Zn),35wt.%(Zn)and 45wt.%(Zn)were mixed in aluminum alloy,after then we conducted a homogenization heat treatment,among the samples we experiment,Al-45wt.%Zn exhibited the best property.Secondly,0.4wt.%(Ti),0.6wt.%(Ti),0.8wt.%(Ti)and 0.4wt.%(Zr),0.6wt.%(Zr),0.8wt.%(Zr)were added to the Al-45wt.%Zn alloy,respectively.Thirdly,after analysis,(Al-45wt.%Zn)-0.6wt.%Ti and(Al-45wt.%Zn)-0.6wt.%Zr were performed 380?×3h+400?×1h,370?×10h+180?×6h,350?×2h+200?×10h heat treatment experiment,respectively.The microstructures and properties of the samples were compared by microscopic observation,X-ray diffraction,damping performance test,room temperature tensile test and micro-hardness test.The results were as follows:(1)In this paper,the damping performance of the alloys was increased as the increase of Zn content.Al-45wt.%Zn alloy has the smallest grain size and the maximum eutectic strengthening phase,which makes the maximum number of movable interfaces.Therefore,Al-45wt.%Zn alloy exhibits the best performance with the Q-1 of 0.012.Compared with Al-25wt.%Zn and Al-35wt.%Zn alloys,its Q-1 was increased by 50%and 16.7%.The tensile strength of Al-45wt.%Zn alloy is 243.1 MPa,the yield strength is 198.75MPa,the elongation is 3.73%,the hardness is 85.85HV.(2)(Al-45wt.%Zn)-0.6wt.%Ti and(Al-45wt.%Zn)-0.6wt.%Zr shows the best Q-1 were 0.014 and 0.013,respectively.Compared with Al-45wt.%Zn alloy,their damping values were increased by 14.3%and 7.7%,respectively.The addition of 0.6wt.%(Ti)and 0.6wt.%(Zr)act as heterogeneous nucleation which lead to the grain refinement and increase the area of grain boundary,and produce intermetallic compounds with Al of the core,dispersion enhancement.The hardness of the cast alloy with 0.6wt.%(Ti)was 94.61HV,increased by 9.3%compared with Al-45wt.%Zn alloy,its hardness value is 101.29HV.(Al-45wt.%Zn)-0.6wt.%Zr showed the strongest hardness with the value of 96.15HV,compared with Al-45wt.%Zn alloy increased by 10.7%.On the one hand,the grain refinement can enhance the hardness of the alloy,on the other hand excessive intermetallic compounds will precipitate in the grain boundary,hinder the grain boundary mobility,contribute to the hardness.(3)(Al-45wt.%Zn)-0.6wt.%Ti alloy achieved the best damping performance with Q-10.0175 through the heat treatment 350?×2h+200?×10h and(Al-45wt.%Zn)-0.6wt.%Zr alloy achieved the best damping performance with Q-1 0.018 through the heat treatment 370?×10h+180?×6h.Compared with Al-45wt.%Zn alloys,their Q-1 increased by 31.4wt.%and 33.3%,respectively;compared with(Al-45wt.%Zn)-0.6wt.%Ti and(Al-45wt.%Zn)-0.6wt.%Zr alloys,their Q-1 increased by 20%and 27.8wt.%,respectively.The tensile strength were 214.21 MPa and 222.39MPa,respectively,and the yield strength were 209.8MPa and 214.31 MPa,respectively.The tensile elongation were 16.05wt.%and 15.87%,respectively,compared with the Al-45wt.%Zn alloy,they increased by 76.7%and 76.5wt.%;the hardness were 128.73HV and 113.67HV,compared with the Al-45wt.%Zn alloy,they increased by 33.3%and 24.5wt.%,respectively;compared with the(Al-45wt.%Zn)-0.6wt.%Ti and(Al-45wt.%Zn)-0.6wt.%Zr alloys,they increased by 26.5wt.%and 15.4wt.%,respectively.They have the best overall performance.With the heating temperature and time increasing,some of the as-cast non-equilibrium phase decomposed,the composition tended to homogenize,lamellar eutectoid phase gradually transformed into granular,and the coherent interface because the non-coherent interface,so the grains were refined and the interface mobility was enhanced,thus they exhibited the best overall performance after heat treatment. |
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