Study On Mechanism And Performance Of Hard Coatings Prepared By Explosive Spraying Of Shaped Charge

As a kind of surface modification technologies,the boundary between surface modification technology and explosive processing technology in the traditional sense had been broken by the Explosive Spraying of Shaped Charge.The powder bombards the substrate to form a coating on its surface.Through the SPH numerical simulation of the explosive spraying process of the shaped charge,we reproduced the spray powder dispersion process.When analyzing the effect of carbon source on coating performance,coatings were prepared with graphite,graphene,and carbon nanotubes as carbon sources,and the coating properties were characterized by SEM,XRD,BSE,and microhardness.The coating made of graphene is more excellent in terms of uniformity and decarburization.With HMX as a gas generating agent,the performance of the prepared coating has been significantly improved When the addition amount of HMX increases from 0%to 10%,the coating area increases by 57.4%,the standard deviation of the coating thickness decreases by64.7%,and the microhardness shrinks by 22%;from 10%to 20,the coating area increases by20.5%,the standard deviation of the coating thickness decreases by 21.8%,and the microhardness decreases by 8.4%.In the experiment of preparing boron carbide coating by explosive spraying,the hard coatings with B₄C and B₈C as the main components were successfully prepared on the substrate with boron or boron oxide,respectively.When boron powder is used as the raw material,the coating area is 31.94cm²,the thickness is 0.218mm,and the microhardness is 2618.1HV_0.3,while when boron oxide is used as the raw material,the coating area is 50.20cm²,which is an increase of 57.17%.The thickness is 0.173mm with a decrease of 20.6%,compared with the microhardness of 2657.0HV_0.3,there is an increase of 1.5%.It proves the feasibility of the explosive spraying technology of shaped charge to prepare boron carbide coating.The coating prepared in this study has excellent performance,which provides a reference for the explosive spraying technology of the shaped charge in the field of surface modification technology.