Study On The Influence Of Recrystallization Organization Of Supersonic Plasma Sprayed High Aluminum Bronze Coatings By Induction Remelting

The multi-aluminum bronze powders that prepared by atomization milling weresuitable for the process of supersonic plasma spraying. The sphericity of the powdersmaterials were proved very good by SEM. The organization of the coating thatprepared on polished45steel substrate by supersonic plasma spraying was observedand analysed by using optical microscope The results showed that the organizationof the coating was compact, the bond between the coating and the base had noobvious metallurgical diffusion light but a mechanical or physical union. The bondbetween the coating and the base was not ideal, which greatly limited the applicationscope of the coating. The induction remelting process was used on the coating forpurificating coating organization and improving the bond strength between thecoating and base. The phase structure and ingredient change of the coating werestudied in the course of the recrystallization. The characteristic of the elementtransfer in the coating and the hardness and shear strength of the coating werestudied too.The coating was heated with high frequency induction heating equipment. Thetext studied on the recrystallization organization of the coating by OM（OpticalMicroscope）, XRD（X-Ray Diffraction）, Jade5.0, SEM, EDS, EPMA, etc. The resultsshowed that the organization of the coating was more compact than that withoutinduction remelting, the bond between the coating and the base had an obviousmetallurgical diffusion light, the phenomenon of the more wide XRD spectrum werecaused by wee grains and micro-strain in the coating without induction remelting.the phenomenon of the more wide XRD spectrum were only caused by micro-strain,the phenomenon of the more pointed XRD spectrum were caused by more sufficientcrystallinity in the coating with induction remelting. The other atoms dissolved intoAlCu3phase in the process of organization recrystallization, the Cu9Al4, AlFe andFeCo phase in recrystallization organization process were stable, Ni dissolved intoFe in the process of organization recrystallization, the black phase in the coatingorganization mainly had the oxide of Al elements in the coating without inductionremelting. The area which Cu and Al were enriched in had poor Ni in the coatingwithout induction remelting, the FeCo, Ni₂MnAl phase were enriched in gray phase.Co elements exist in particles junction, while Fe and Mn element exist in the organization uniformly in the coating without induction remelting. However, Cu andAl exist in the organization dispersedly, Fe and Co element moved into the grayphase, the shapes of gray phase that contained the organization of net shapes richedin Fe and Co poor in Ni and Mn turned to flowers shapes in the coating withinduction remeleting. The behavior of element diffusion maintained the originalperformance in the process of recrystallization with Induction remelting. Thediffusion driving force of Co and Ni were the strong adsorption of Fe atoms in basein the process of induction remelting, the Mn elements out from Ni2MnAl phasediffusion transfered along with the Fe.The hardness of the coating was tested by using electron microscopic hardnesstester the shear strength of the coating was tested by using microcomputer controlelectronic universal test machine. The results showed that the hardness of thecoating with induction remelting had higher hardness than that without inductionremelting, the hardness of the bond between the coating and base was up to746.5HV.The form of the coating itself fracture was brittle fracture, while the form of bondbetween the coating and base fracture was cleavage fracture, in the coating withoutinduction remelting. However, the form of the coating itself fracture was also brittlefracture, while the form of bond between the coating and base fracture was acomplex brittle fracture contained ductile fracture and brittle fracture, in the coatingwith induction remelting.