| Kerosene and oxygen are combusted inside HVOF gun and generate supersonic jet which will carry the powder sent by gun to fly to the workpiece where the coating is formed.It is difficult to describe the influence of process parameters on the coating due to the influence of different process parameters on coating.Process parameters on the coating because the different parameters can get different jet temperature reaching the workpiece(T_s),so the jet temperature can be as an intermediary when analyze the influence of process parameters on the coating,but the problem is that it’s difficult to directly measure the jet of HVOF due to its high temperature and high-speed,in order to solve this problem,the research content is as follows:Firstly,the jet temperature field of HVOF was analyzed and simulated based on dynamics of rocket jet spray gun.A method that indirect measuring multi-point temperature to obtain the jet inside the jet characteristics of temperature distribution was come up according to the results of the theory,and a on-line temperature measuring system was built.Secondly,the reliability of the measurement method was explained because the experimental results are consistent with the theoretical calculation results.According to the measurement method,the calculation formula of the jet temperature was deduced,and the experimental verification was carried out.Finally,the relationship between process parameters and T_s value was analyzed by experimental results,and the relationship between T_s value and coating performance was analyzed.The results show that when the T_s is 489.7℃,minimum porosity was 0.28%,the coating structure coating HV1233.7 maximum microhardness.In this paper,the jet temperature distribution characteristics were studied and could provide a reference for the preparation of high-performance coating. |
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