Al-Si-Cu-Fe压铸合金搅拌摩擦加工表面改性后的组织及冲蚀磨损性能  

Structure and Erosion Wear Resistance of Al-Si-Cu-Fe Die-Casting Alloy Modified by Friction Stir Processing

作　　者：赵松[1] 魏忠斌[1] 付欣毓 ZHAO Song;WEI Zhong-bin;FU Xin-yu(Department of Mechanical and Electrical Technology, Xijing University, Xi'an 710123,China;Shaanxi Fast Auto Drive Group Company, Baoji 722409,China)

机构地区：[1]西京学院机电技术系,陕西西安710123 [2]陕西法士特汽车传动集团公司,陕西宝鸡722409

出　　处：《材料保护》2019年第3期13-17,共5页Materials Protection

基　　金：国家科技重大专项(2017ZX04011010);西京学院科研计划项目(150215)资助

摘　　要：目前,通过搅拌摩擦加工(FSP)表面改性来改善材料表面冲蚀磨损性能的报道较少。对Al-Si-Cu-Fe过共晶压铸铝合金实施了搅拌摩擦加工(FSP),利用扫描电镜(SEM)、二次电子像(SEI)、背散射电子像(BEI)及冲蚀磨损试验机,研究了FSP对铸铝组织演化及表面冲蚀磨损性能的影响规律。研究表明:压铸合金中除α-Al基体外,第二相主要为共晶Si、β-Al3(Fe,Mn) Si2相以及少量的初晶Si;经过搅拌摩擦加工后,第二相的类别未发生变化,但α-Al相及第二相颗粒均被细化;压铸合金中第二相为长宽比较大的颗粒,受到冲蚀后发生断裂,使颗粒与基体间形成微孔洞;而FSP合金中第二相颗粒长宽比较小,且分布均匀,因此冲蚀过程中脆性断裂较少,从而降低了冲蚀磨损过程中合金的冲蚀率;压铸合金及FSP合金冲蚀率均随着冲蚀攻角增大而减小。There are few reporters on friction stir processing( FSP) for improving the erosion wear resistance of material surface. In this work,FSP was performed on Al-Si-Cu-Fe hypereutectic die-casting aluminum alloy. Subsequently,scanning electron microscopy( SEM),secondary electron image( SEI),backscattered electron image( BEI) and erosion wear tester were used to study the influence mechanism of FSP on the microstructure evolution and surface erosion wear properties of cast aluminum. Results showed that in addition to the α-Al substrate in the die-casting alloy,the second phase mainly included eutectic Si,β-Al3( Fe,Mn) Si2 phase and a small amount of primary Si. After the FSP treatment,the type of the second phase did not change,but the particles of both α-Al phase and the second phase were refined. Moreover,the second phase of the die casting alloy became particles with large length-width ratio,which would break after being eroded,resulting in the formation of micro voids between the particles and the substrate. However,the second phase particles in FSP alloy possessed small length-width ratio and uniform distribution,so brittle fracture occurred less in the erosion process,which reduced the erosion rate of the alloy in the erosion process. Besides,the erosion rate of die cast alloy and FSP alloy decreased with the increase of erosion angle.

关 键 词：压铸铝合金 搅拌摩擦加工 冲蚀磨损 冲蚀攻角 

分 类 号：TH117.1[机械工程—机械设计及理论]