| Free-abrasive wire sawing in the magnetic field,a new promising silicon wafer technology,is advantageous due to its wide cutting range,high cutting efficiency,low energy consumption and manageable.Therefore,its continuous development will widely promote the advance of the photovoltaic industry and the semiconductor industry.As grinding tools,magnetic abrasive is the key of free-abrasive wire sawing in the magnetic.In this paper,all experiments are based on the traditional sintering method and requirements from free-abrasive wire sawing in the magnetic,and designed with the composition of magnetic abrasive.In order to get uniformly dispersed SiC powder,home-made PEG300 dispersant has been used to modify the SiC powder surface.Also,all-cover method replace the traditional composition method and blend-ultrasonic disperse-blend method have been put into experiments to make powders mixed uniformly.Furthermore,a series of magnetic abrasives were prepared under the absence of climate protection.Then we have studied how pressure,sintering temperature,SiC size and sintering time take effect on properties of magnetic abrasives.Finally,we compared the magnetic abrasive of superior performance with the magnetic abrasives we bought by conducting cutting experiments.By analyzing the results,some conclusions are drawn:?1?Home-made PEG300 dispersant can significantly improve the liquidity of SiC powder,hence making SiC powder dispersed more uniformly in mixed powders.The more mesh SiC powder has,the better performance on surface modification.The preparation technology was optimized combined with blend-ultrasonic disperse-blend method.?2?Sintered density of magnetic particles rises with the increase of pressure,sintering temperature,and SiC mesh.In the other hand,with sintering time increasing relative permeability decreasing as sintering temperature and sintering time increasing,while it rising as pressure and SiC mesh increasing.The sintered density maximum of prepared magnetic abrasives is 3.30g/cm3,while the minimum is 1.73g/cm3.The relative permeability maximum of prepared magnetic abrasives is 0.71,while the minimum is 0.24.?3?Sintering temperature is the key factor of properties.By the orthogonal experiment research,best preparation technology parameters are confirmed:sintering temperature1100?,sintering time 4h,pressure 6T and SiC mesh 1500.?4?The kerf width and collapse edge width of prepared magnetic abrasives are 523.45?m and 85.35?m,while these of magnetic abrasives bought are 523.45?m and 85.35?m.And cutting efficiency of prepared magnetic abrasives is 2.737×10-4g/s,while the one of magnetic abrasives which are bought is 3.111×10-4g/s. |
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