Study On Process Of Aluminum Bronze Plasma Surfacing

With the rapid development of industry technology and continuous increase of the degree of mechanization and automation,people pay more attention to hazard of parts wearing.It has a great economic significance to improve the wear resistance of parts and components.This topic is the use of reverse polarity plasma arc as source of heat to melt aluminum bronze alloy powder surfacing in the test plate.The effect of surfacing processing parameter on overlay's mechanical properties is studied through analyzing the average degree of hardness,the frictional wear testing and the microstructure.The mechanism for plasma arc overlay formability,composition and surfacing layer interface bonding mechanism by overlay surfacing processing parameter has been discussed intentionally.The paper also makes theoretical analysis and preliminary discussion on the wear resisting mechanism of the overlay.Following are the main results:(1)Through compare normal polarity plasma arc welding sample to reverse polarity,The latter surfacing layer compactibility which is superior to the former.In the condition of normal polarity plasma,materials Crack penetration is more easily found.(2)Aluminum bronze surfacing layer microstructure is composed of? phase,?2 phase,?? phase and K phase,?2 phase,?? phase and K phase are hard phase under different surfacing welding current.With the current changes basal body ? phase gradually strip into sheet by sheet.K phase with the current increase becomes large.(3)In the condition of plasma surfacing welding,between surfacing layer and material is a typical combination of metallurgy,because it has good interface bonding.In the cladding layer and the matrix element at the junction of each group showed a gradient distribution of concentration,elements in the case of the diffusion.(4)On the surfacing layer of Q245 R,The frictional wear's weight loss and length loss of plasma arc welding layer with metal grinding friction are become small first and then increase with the welding current increasing.In the condition of same current,The frictional wear's weight loss and length loss of plasma arc welding layer with metal grinding friction are become increase with the load increasing.When the welding current of110 A,load of100 N.The frictional wears weight loss and length loss of plasma arc welding layer with metal grinding friction obtain minimum valuation,which are 6.0 mg and 0.12 mm.(5)In the same welding current,the same load under the conditions of the experiment,the frictional wear's weight loss and length loss of surfacing layer of HT200 less of Q245 R.