Finishing Technique Of Pressure Grinding Wheel With Softness Fixed Abrasive And Experimental Study

The modern machining demand for molds is required to be increasingly improved. There are more free-form surfaces with high hardness and wear resistance. In the traditional processing methods of molds, free abrasive can make copying contact with free-form surfaces, but low cutting force has difficulty to cut the surface with high hardness and wear resistance effectively. And rigid lapping tools can not make good surface contact with machined surface. So the application of this traditional processing method has its limitation.According to the processing characteristics of free-form surfaces with high hardness and wear resistance, a new finishing technique of pressure grinding wheel with softness fixed abrasive was proposed in this thesis, which had advantages of the copying ability of polishing tools and their effective cutting force. The abrasive was consolidated on the surface of polymer grinding wheel, it made use of elastic support of gizzard to generate good surface contact and effective cutting force so that the machining efficiency and quality is good.The main work of this thesis is shown as follows:1) The finishing technique of pressure grinding wheel with softness fixed abrasive was proposed, and it put forward the structure and material composition of pressure grinding wheel with softness fixed abrasive. In terms of chemical properties, physical properties, force conditions and allowed processes, several selection bases were introduced to choose adhesives as well as bonding behaviors.2) According to the layer structure of pressure grinding wheel, there were two kinds of manufacture process schemes. The performance evaluation indexes, which were composed of lossless surface quality, press amount, hardness and fallout production of abrasive, were established to verify whether the grinding wheel was suitable for machining.3) Based on the layered elastic architecture, the calculation formulas of stress and displacement component were derived and the computational expressions which just including material property parameters were supported.4) By model building of grinding wheel, the stress distribution of rubber layer, adhesive layer and abrasive layer was simulated, it investigated the stress changing generated by changing layer thickness. From the analysis results, the optimization thickness of rubber is 3 millimeters and the optimization thickness of adhesive is 0.5 millimeters.5) Experimental research and performance testing were done by preparing ten grinding wheels with different material composition and it obtained the optimization adhesive. On the basis of optimization adhesive, six pressure grinding wheels with different thickness were prepared to study the processing effects affected by the thickness of adhesive layer. The results show that the finishing effect is the best when the thickness of adhesive layer is 0.5 millimeters.This thesis has some significant theoretical guidance and technical reference value for the finishing efficiency and quality of free-form surface mould with high hardness and wear resistance.