Preparation And Performance Analysis Of Diamond Coated Tool Coating Based On Stone Processing

Diamond has been widely used in the industrial field due to its high hardness,low friction coefficient,high thermal conductivity and good corrosion resistance.The CVD diamond coated tool is a new type of cutting tool.Based on the cemented carbide forming tool,a diamond coating is deposited by chemical vapor deposition to improve the wear resistance and surface hardness of the tool.The use of CVD diamond coated tools in stone processing can improve the precision and processing efficiency of the processed stone surface and prolong the service life of the tool to a certain extent.At present,domestic universities and research institutes have less research on the application of diamond coated tools in the field of white marble stone.According to the above research background,this paper used hot filament chemical vapor deposition(HFCVD)technique to prepare diamond single-layer coating on the surface of cemented carbide substrate and cemented carbide tool.The surface morphology,surface composition and cutting performance of the tool are studied and the heat is analyzed.The preparation of gradient films by HFCVD is also explored,and the main research contents of this paper are as follows:1.The process of hot filament chemical vapor deposition of cemented carbide matrix diamond coating was studied.Different carbon source concentration diamond coatings were prepared on the surface of the cemented carbide substrate by HFCVD.The results showed that the 1%carbon source has a larger grain size and less sp2 bonds,and the<111>crystal plane has a higher characteristic peak intensity,and the grain orientation showed that the microcrystalline diamond was compared with the 2%and 3%carbon source concentration diamond coating.The typical<111>crystal plane of the diamond coating with 3%carbon source concentration disappears,and the grain orientation shows nanocrystalline diamond.2.The effect of different carbon source concentrations on the cutting performance of deposited diamond coated tools was studied.White marble was cut by a diamond coating cutter with different carbon source concentrations for 1 h on the DMU50 machining center The results showed that the diamond-coated milling cutter with a carbon source concentration of 3%has the largest flank wear.The coating of 1%carbon source concentration diamond coated cutter has high bonding force with the substrate,and the wear of the flank of the milling cutter is the smallest.The diamond coating has no obvious peeling,and the cutting life is the longest.3.The preparation methods and properties of diamond gradient films with different structures were studied.Three types of diamond gradient films with two layers,three layers and five layers were prepared on the alloy substrate by hot filament chemical vapor deposition.The results showed that the internal stresses of the films with 2 layers,3 layers and 5 layers are-11.644 GPa,-0.737 GPa and-0.567 GPa,respectively.The film with 5 layers has the minimum stress.Through the indentation test,it can be seen that the diamond gradient coating with 2 or 3 layers of coating has less diamond shedding,and the diamond gradient film with 5 layers of coating is obviously peeled off.According to the friction and wear test,the friction coefficient of the 2 layers diamond gradient film is the lowest,the friction coefficient of the 3 layers is the highest,and the 5 layers is the second.The gradient layer can effectively reduce the internal stress.While reducing the internal stress,the thickness of the micro-diamond must be ensured to meet the pinning effect.The addition of nano-diamond in the gradient layer can reduce the friction coefficient.