Study On The Performance Of Wear And Impact Of Al₂O₃ Ceramic Thermal Spraying Coating

Surface engineering technology is the important part of the advanced manufacture technology, and which afford technology support novation of the advanced manufacture technology. Surface engineering technology is particular advantage on surface protected, surface repair, changing the performance of surface etc. Thermal spraying is one of surface engineering technology, with the development of thermal spraying technique and materials, thermal spraying coating extend the range of material applications, enhance the work life of parts, saving the sources.Thermal spraying crafts, materials, and interrelated assistant crafts are investigated, that is base on the part surface demands that includes insulation, resisting wear and impact. The material of part is 45 steel, the detonation flame praying is elected, the spraying materials are micron Al₂O₃ ceramic powder and nylon 11 powder. Al₂O₃ ceramic coating and agglomerated Al₂O₃ ceramic coating are prepared on 45 steel, and nylon 11 coating is prepared by flame spraying.The structure and the size of grain of the coating are observed by the optical microscope. The crystal structure of the coating is mensurated by the X-ray diffraction technique. The degree of crystal of nylon 11 coating is mensurated and accounted by X-ray diffraction technique. According to JB/T 7509-94, the rate of hole about AI2O3 ceramic coating is mensurated by the steel reagent technique, the experiments results indicate that the structure and the size Al₂O₃ ceramic coating is fine and compact; the crystal structure of the coating is more stabilization; the degree of crystal of nylon 11 coating is high, which can keep the nylon 11 original good performance after thermal sprayed.The performance of wear of the Al₂O₃ ceramic coating and nylon 11 coating is mensurated by MM200 wear experimentation machine, the mode of friction is ring- block friction without lubricant, the experiments results indicate that the performance of wear of the Al₂O₃ ceramic coating is great, which is better than 45 steel and nylon 11 coating, when the Al₂O₃ ceramic coating is lubricity, the quantity of wear change is little following time, which is equal to wear.The bond strength of coating is mensurated by CMT5105 experimentation machine, the breakage of Al₂O₃ ceramic coating is between layers, the bond strength of undercoat is proved by spraying the NiAl powder, the bond strength of nylon 11 coating is great.The performance of impact of coating is mensurated by the impact experimentation machine and a steel ball, the performance of impact of the parts is played down with coating.The quality of Al₂O₃ ceramic coating prepared by detonation flame praying is good, the performance of wear of the Al₂O₃ ceramic coating is great and equal to wear, but it is not equal to impact, the bond strength and the performance of impact of nylon 11 coating is great, which can improve the performance of Al₂O₃ ceramic coating by appending nylon 11 into Al₂O₃ ceramic coating, the coating will obtained which can resisting wear and impact.