Friction stir surfacing of cast A356 aluminiumesilicon alloy with boron carbide and molybdenum disulphide powders  

作　　者：R.SRINIVASU A.SAMBASIVA RAO G.MADHUSUDHAN REDDY K.SRINIVASA RAO 

机构地区：[1]Department of Metallurgical Engineering,Andhra University [2]Defence Metallurgical Research Laboratory

出　　处：《Defence Technology（防务技术）》2015年第2期140-146,共7页Defence Technology

基　　金：DRDO-ER&IPR (No:1104584\M\1387), New Delhi, India for the sponsoring the research project

摘　　要：Good castability and high strength properties of Ale Si alloys are useful in defence applications like torpedoes,manufacture of Missile bodies,and parts of automobile such as engine cylinders and pistons.Poor wear resistance of the alloys is major limitation for their use.Friction stir processing(FSP) is a recognized surfacing technique as it overcomes the problems of fusion route surface modification methods.Keeping in view of the requirement of improving wear resistance of cast aluminiumesilicon alloy,friction stir processing was attempted for surface modification with boron carbide(B4C) and molybdenum disulfide(Mo S2) powders.Metallography,micro compositional analysis,hardness and pin-on-disc wear testing were used for characterizing the surface composite coating.Microscopic study revealed breaking of coarse silicon needles and uniformly distributed carbides in the A356 alloy matrix after FSP.Improvement and uniformity in hardness was obtained in surface composite layer.Higher wear resistance was achieved in friction stir processed coating with carbide powders.Addition of solid lubricant Mo S2 powder was found to improve wear resistance of the base metal significantly.Good castability and high strength properties of AI-Si alloys are useful in defence applications like torpedoes, manufacture of Missile bodies, and parts of automobile such as engine cylinders and pistons. Poor wear resistance of the alloys is major limitation for their use. Friction stir processing （FSP） is a recognized surfacing technique as it overcomes the problems of fusion route surface modification methods. Keeping in view of the requirement of improving wear resistance of cast aluminium--silicon alloy, friction stir processing was attempted for surface modification with boron carbide （B4C） and molybdenum disulfide （MoS2） powders. Metallography, micro compositional analysis, hardness and pin-on-disc wear testing were used for characterizing the surface composite coating. Microscopic study revealed breaking of coarse silicon needles and uniformly distributed carbides in the A356 alloy matrix after FSR Improvement and uniformity in hardness was obtained in surface composite layer. Higher wear resistance was achieved in friction stir processed coating with carbide powders. Addition of solid lubricant MoS2 powder was found to improve wear resistance of the base metal significantly.

关 键 词：A356合金 二硫化钼 堆焊技术 硅合金 钼粉末 碳化硼 摩擦 铸铝 

分 类 号：TB306[一般工业技术—材料科学与工程]