Research On The Material Removal Mechanism Of Semi-Fixed Abrasive Tool

With the development of information technology, photoelectron technology and aerospace technology, the requirement of process is more and more higher, and the need of process which has the performance of high efficiency, high precision and low surface damage keeps increasing. The abrasive particle process includes fixed abrasive process and free abrasive process, but these methods couldn't meet above requirements. In the free abrasive process, the abrasive is free completely, and the abrasive is fixed by bond completely in the fixed abrasive process. A new process method called semi-fixed abrasive particle process is proposed in this paper. The particle restriction of the semi-fixed abrasive particle process is between free completely and fixed completely. The abrasive particle can adjust its place with the press to assure more abrasive particle enlisted in and lower the press on single particle. So the precision of process is preferable and the efficiency of process is high. If there is big hard particle in process, the big hard particle will embed into the abrasive tools in high press. In this way, it can reduce thesurface damage caused by big hard particle.The removal mechanism of ceramic materials such as Silicon experimental research is employed based on the SFAP. Many testing instruments are used to analyze main characters of the SFAP. The superficial characters of abrasive tool are tested by Nano-indentation tests, and the loading-displacement character of superficial abrasive particles during loading is gotten. The contact characteristic between the SFAP with workpiecewas studies by contact experiment .The best experiment parameters are selected and obtains results of removal rate and Surface roughness by using these parameters in experiments. A SFAP experiment is carried out with the silicon compared with the free abrasive. SEM and AFM are used to analyze the surface defect to find the removal mechanism. The main works and research results in the paper were summaried as following: (1) Many testing instruments are used to analyze main characters of the SFAP. In the same weight percentage of abrasive, hardness value of surface and Shear strength are smaller when grain size of SFAP is larger. When the weight percentage of abrasive is 65%, the shear strength is the best and the density is the highest, abrasive and stomatal distributed are better. The elastic modulus of SFAP is rising with the grain size increases.(2) Nano-indentation tests show that the superficial bond generate plastoelastic deformation during loading. When the external load reaches the yield limit point of the bond, the bond yielded.(3)It is found that the surface morphology of SFAP is very rough and being many prominent peaks by using SEM. The contact experiment between SFAP and workpiece finds that peaks will lift when load increases. The contact area increases with the load increases.(4)Experiments find that the load, the revolve speed and the flow are effected : material removal rate and roughness increase with the load increases. Material removal rate increases in a straight line when the revolve speed of SFAP increases from 20rpm to 60rpm, and the roughness increase a little. The material removal rate gradually increases and the roughness gradually reduces with the flow increases when the flow is less than50ml/min.(5) A SFAP experiment was carried out with the optimal parameters and compared with the free abrasive under the same processing conditions. SEM and AFM were used to analyze the surface defect to find the removal mechanism. It is found that the main remove style of the SSB-2 SFAP is two-body wearing, it can explain that the SFAP processing is the ductile regime. At last, it is proved that ceramic materials can be processed with high speed and high precision by experiments.