摘要
目的在ADC12半固态铝合金基体内添加(Sr+Y)复合稀土改善其凝固组织形貌并提高其力学、摩擦磨损性能。方法利用立式万能摩擦磨损试验机、电子拉力机、显微硬度计、光学显微镜及扫描电子显微镜等研究了(Sr+Y)复合稀土对半固态ADC12合金微观组织、力学性能及摩擦磨损性能的影响。结果当未添加混合稀土时,半固态ADC12合金组织呈现出粗大的树枝晶状形态,初生α-Al相大多数为巨型椭圆状或长条状,而添加了0.5%(质量分数)的(Sr+Y)复合稀土后,合金组织得到显著细化,初生α-Al相变得更加圆整,且分布更加均匀,晶粒大小趋于一致。0.5%(Sr+Y)/ADC12合金的屈服强度、抗拉强度及伸长率分别为158.23 MPa、212.83 MPa和5.6%,与不含稀土(Sr+Y)的半固态ADC12合金相比,屈服强度、抗拉强度及伸长率分别提高了27.24%、31.56%和64.71%。磨损率及平均摩擦系数随载荷变化的曲线分析结果表明,0.5%(Sr+Y)/ADC12合金的摩擦磨损性能最佳,在高载荷或低载荷的摩擦作用下,其磨损率及摩擦系数均比不含稀土的半固态合金的低。随着摩擦载荷的逐渐增大,变质处理前后合金的磨损率均呈现出变大的趋势,而摩擦系数均呈现出变小的趋势。结论(Sr+Y)复合稀土的添加可以显著细化ADC12半固态铝合金微观组织形貌,提高合金的性能,当(Sr+Y)复合稀土的质量分数为0.5%时,半固态合金材料的组织细化最为明显,力学性能及摩擦磨损性能最佳。
The work aims to add(Sr+Y)composite rare earth elements to the ADC12 semi-solid aluminum alloy matrix to improve its solidification microstructure morphology and enhance its mechanical and tribological properties.Effects of(Sr+Y)complex rare earth on the microstructure,mechanical and friction and wear properties of semi-solid ADC12 alloy were studied by vertical universal friction and wear testing machine,electronic tension machine,microhardness tester,optical microscope and scanning electron microscope.Before the addition of mixed rare earth,the semi-solid ADC12 alloy microstructure presented a coarse dendrite shape,and the primary α-Al phase was mostly giant elliptic or long strip,but the alloy microstructure was significantly refined after the addition of 0.5wt.%(Sr+Y)composite rare earth,and the primary α-Al phase transition was more rounded,and the distribution became more uniform,and the grain size tended to be consistent.The yield strength,tensile strength and elongation of 0.5wt.%(Sr+Y)/ADC12 alloy were 158.23 MPa,212.83 MPa and 5.6%,respectively.Compared with semi-solid ADC12 alloy without rare earth(Sr+Y),the yield strength,tensile strength and elongation were increased by 27.24%,31.56%and 64.71%,respectively.The curve analysis of wear rate and average friction coefficient with load showed that 0.5wt.%(Sr+Y)/ADC12 alloy had the best friction and wear performance,and its wear rate and friction coefficient were lower than those of semi-solid alloys without rare earth under high or low load.With the increase of friction load,the wear rate of the alloy increased and the friction coefficient decreased before and after modification.In conclusion,the addition of(Sr+Y)composite rare earth can significantly refine the microstructure and morphology of ADC12 semi-solid aluminum alloy,and improve the performance of the alloy.When the content of(Sr+Y)composite rare earth is 0.5wt.%,the microstructure refinement of the semi-solid alloy material is the most obvious,and the mechanical and friction wear properties are the best.
作者
刘军伟
高培虎
王亚
ANTON Naumov
LIU Junwei;GAO Peihu;WANG Ya;ANTON Naumov(Jiangsu College of Safety Technology,Jiangsu Xuzhou 221011,China;Xi'an Technological University,Xi'an 710021,China;Peter the Great St.Petersburg Polytechnic University,Saint Petersburg 195251,Russia)
出处
《精密成形工程》
北大核心
2025年第11期208-219,共12页
Journal of Netshape Forming Engineering
基金
国家外专项目(H20240023)
陕西省教育厅青年创新团队
西安市科技计划(23LLRHZDZX0019,23GXFW0036)
咸阳市重点研发项目(L2024-ZDYF-ZDYF-GY-0039)。
