| Our group developed the alminum bronze alloy,whitch is an excellent wear and corrosion materials.In order to further use the alloy to the field of surface engineering, the first take three different nitrogen atomization granularity of alminum bronze alloy powder,and then analyze structures and properties of all powders.Futher,take methed of plasma spray welding coating,on condition that spray welding process parameters are the same,put the three different granularity of the alloy powder on the 45# steel substrate preparating spray coating.At last,analyze the formation of the three kinds of solder powders granularity and propertiesAluminum bronze alloy powder and plasma spray coatings microstructure was studied by SEM,X-ray diffraction, EPMA and other methods.The results showed that:Aluminum bronze alloy powder prepared by atomization whose granularity was close to spherical shape,surface structure was smooth, density was good and granularity distribution was more uniform with the powder mesh increashed,, sphericity and mobility are getting better and better.but when the granularity reached-280～+320 mesh,mobility is getting worse.By analyzing,the powder with-200～+250 mesh has the best mobility.Through the analysis of weld layer structure,the three granularity alloy powder spray coating are consist of a solid solution (white),βsolid solution (gray) and distributed in the a phase matrix of K(black).The phase of three kinds of granularity alloy powder spray coating are Cu9Al4, AlFe3,AlFe and Fe3Mn7. Three kinds of granularity alloy powder spray coating and the substrate are formed a metallurgical bonding whose strength is good,of which powder of -200～+250 mesh,the formation of spray coating powder metallurgical bonding zone is wide.The formation of avarity of powder spray coating has the characteristics of rapid solidification,so dose the microstructure of the organization.Different granularity of powder forming spray coating has a significantly influence on aluminum-bronze -200～+250 mesh powder sprayed coating formed dendrites are smaller,structures are more uniform.Macro-hardness and micro-hardness of the bronze alloy power and the plasma spray welding coatings have been tested in HBRV-187.5 Brinell Rockwell Vickers hardness tester and HX-1000TM digital micro hardness tester, the tensile bond strength was tested in tensile test machine.The results showed that:Firstly,with the increasing of the powder mesh,alloy powder micro-hardness increased.And an average hardness value is 414HV. Secondly, three different granularity powder coatings hardness generally rang from 300 HV to 400HV,and its combination of mircrohardness peak appear in the binding layer. Thirdly,-200～+250 mesh alloy powder spray coating surface hardness is uniform and maximum,and the averagen hardness is 309HV,-150～+180 mesh and -280～+320 mesh alloy powder spray coating surface hardness is not uniform,the average hardness is 287HV and 293.5HV. Fourthly,The bonding strength of-200～+250 mesh alloy powder spray coating is the highest,whitch reached 421 MPa, while the bonding strength of -150～+180 mesh alloy powder spray coating is the lowest,which is only 297.8 Mpa.Fifthly,from the microscopic morphology of the fracture granularity can be drawn at -200～+250 mesh,the micro-damage mechanism is void growth specificly,aggregution model and material have the typical characteristics of ductile fracture,which shows the granularity spray under coating has good strength and ductility,whitch results with the macroscopic mechanical properties is consistent.
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