| Diamond grinding wheel possess the advantages of good self-sharpening,high bonding strength,controllable porosity,and high precision grinding.It has fundamental application in semiconductor substrate materials with high hardness,large brittleness and great precision requirements.However,the traditional manufacturing method of diamond grinding wheel is mainly mold pressing,which requires a series complex processing techniques.Additionally,the design of traditional manufacturing method is limited,the cost is high and the production period is long.The birth of 3D printing technology solves the above-mentioned problems in the traditional manufacturing process.It can fabricate tools with complex structures in an integrated way,effectively shortening the research and development cycle and reducing production costs.Among them,the direct ink writing technology does not require lasers and any molds in the preparation process,and it has fast molding speed,high precision,and a wide range of applicable materials,so it has received widespread attention.In this paper,the direct ink writing technology was proposed to fabricate diamond grinding wheel.Firstly,this paper determined the formula of the grinding wheel based on the direct ink writing technology.This paper selected the appropriate binder material and ceramic powder,mixed the resin solution and ceramic powder to prepare a slurry to achieve non-collapse printing;added different contents of pore-forming agents to achieve controllable porosity.Secondly,the preparation process of diamond grinding wheel is explored.The study adjusted the maximum sintering temperature of ceramic agglomerates,the curing temperature and environment of ceramic/resin agglomerates to ensure the mechanical properties of the agglomerates.Finally,diamond grinding wheels with complex structures are designed to improve grinding efficiency.Porous vitrified bond grinding wheel and patterned ceramic/resin bond grinding wheel were prepared to verify the grinding effect of different structure grinding wheels on sapphire substrate.The experimental research and analysis showed that the preparation of diamond grinding wheel by direct ink writing technology can achieve efficient forming and grinding.For vitrified bond grinding wheel,adding 3% xanthan gum solution to N68 ceramic powder can realize extrusion and stable molding;adding 30% PMMA poreforming agent content has the highest porosity;for vitrified/resin bond grinding wheel,A+X+W10 grinding wheel and B+Y+W10 grinding wheel meeted the requirements of stable extrusion molding.The mechanical properties and porosity of the vitrified bond grinding wheel can meet the best requirements after sintering at the highest temperature of 670 °C;the A+X+W10 grinding wheel is dried in a constant temperature oven at50 °C for 24 hours;the B+Y+W10 agglomeration is cured at room temperature(25°C)for 5-7 days.For vitrified bond diamond grinding wheel,three different structure grinding wheels are designed: solid structure,triangular structure and grid structure.The surface roughness of the substrate can be reduced to below 140 nm by vitrified bond grinding wheel after 30 minutes.The material removal rates of the triangular structure and grid structure grinding wheel are respectively 1.6 times and 1.8 times that of the solid structure;for the vitrified/resin bond diamond grinding wheel,two patterned shapes of ring and tooth are designed,and the grinding efficiency of the tooth structure is about 1.15 times that of the ring structure.After grinding with A+X+W10grinding wheel,the surface is relatively smooth,without obvious pits and scratches,and the surface roughness is the lowest;after grinding with B+Y+W10 grinding wheel,there is a small amount of undulation on the surface,and after grinding with vitrified grinding wheel,the grinding efficiency is the highest,while there are scratches on the surface.This paper verifies the feasibility of preparing diamond grinding wheel by direct ink writing technology,and provides ideas for further research. |
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