Study On Friction Welding Technology Of The Type Of Hard Alloy To Structural Steel

The systematic and deep-going researches on friction welding technology of the type of YG Hard alloy with lower density to structural steel have been undertaken in this paper.The optimum parameters of the friction welding between the type of YG Hard alloy and structural steel have been provided, the phisical model of interface at the joit has been set up, the determined formula about the control of the interface appearance has been made, the affected regular of the thickness of the intermediate material on the friction weldability has been researched, the fracture reason of joint has been revealed, and a growing model of fragile layer at interface of the joint has been established through the researches of direct friction welding, friction welding with intermediate materials.and through the analysis and test to the structure and quality of the joint.The experimental results indicate that the weldability of YG hard alloy and structure steel is poor and the joint can not be obtained in direct friction welding of YG 11 to structural steel. The main reasons of joint's fracture are the formation of fragile layer in interface of joint and the occurrence of phase change stress during martensitic transformation of structural steel. However, the high strength joint can be obtained by joining the intermediate materials and the maximum strength of joint is up to 77MPa.The stage achievements made in this research found a foundation in theory and practice for the further development and application of gamma titanium aluminide.