Experimental Research On Bonding Mechanism Of The Crosswedge Rolling 42CrMo/Q235 Composite Shaft

Generally axial parts service environment is relatively complex,prone to failure problem such as fatigue and fracture.Composites attracted much attention because of its superior performance.Study of composite shaft parts was more concentrated in forming condition,forming the interface morphology and performance analysis of the cross section such as composite panels,composite rods or pipes,but the influence of process parameters on the interface bonding for the forming process of variable cross-section laminated shaft there is few research done regarding.The cross wedge rolling process was relatively advanced near net shape technology for the production of variable cross-section shaft parts.Also the cross wedge rolling process has advantages like good formed quality and easy to realize the automatic machinery compared with other process.This paper used the method of the cross wedge rolling achieved heterogeneous material composites.The cross wedge rolling mold deformation zone is complex,and the interface bonding mechanism of this process is unclear,thus revealing the interface bonding mechanism in rolling process is the key scientific problems.In this paper,experiment research to improve the interface bonding strength of the composite shaft.Also it has great significance expounds the influence of the rolling process parameters on the interface bonding mechanism and the influence law of interface bonding performance.In this paper,on the basis of experiment,research under different technological parameters of rolling,cross wedge rolling 42CrMo/Q235 composite shaft interface microstructure,Cr element diffusion,microhardness,bonding strength and interface properties such as tensile fracture surface morphology judgment affect cross wedge rolling composite shaft parts well bonded and macroscopic mechanical properties of excellent key process parameters and the influence of the main aspects,thus the reasonable inference mechanism of cross wedge rolling composite shaft interface composite.The experimental results show that in the rolling under high temperature and high pressure,the 42CrMo/Q235 composite shaft forming,main process parameters change affect combines the oxide film and broken and elements diffusion of interface to affect the combination of the interface.Rolling temperature and rolling reduction of area has a decisive effect on interface bonding,the interface bonding strength in the increase of rolling temperature decreases after increasing first,reached the maximum at 1100?;Interface bonding strength increased with the increase of rolling reduction of area,necking phenomenon,began to appear in the 65% more ideal rolling reduction of area is 60%;On the basis of the interface bonding,base diameter d before rolling and forming Angle alpha,broadening Angle beta less impact on the interface bonding,the influence of different parameters on the interface bonding strength in a smaller range.Preliminary judgment cross wedge rolling 42CrMo/Q235 composite shaft interface bonding is divided into three stages: the physical contact,physical chemistry,diffusion phase.In this paper,in order to optimize the rolling technology and improve the interface bonding strength to provide experimental basis,for the research of other heterogeneous metal rolling composite forming and the interface bonding mechanism laid a foundation.