Research On The Process Performance 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 the surface damage caused by big hard particle.In this paper, the research on semi-flxed abrasive tool manufacture process is developed based on the characters of semi-fixed abrasive tool and the manufacture process of conventional abrasive tool. The recipe and available process of molding and solidifying are found through experimental research. 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. It shows that the superficial bond generate plastoelastic deformation during loading. When the external load reaches the yield limit point of the bond, the bond yielded.The material removal mechanics is analyzed by microscopic observation of the workpiece's surface pattern after processing. The analysis shows that dividing and rolling coexist as material removing forms, and diving is the main way in processing of the semi-fixed abrasive machining.With the surface "load-displacement" characteristics got from the tested result, a relationship of workpiece-force and cutting-depth is established based on dynamics analysis. According to material removal depth of the workpiece surface and the theoretical analysis, Material Removal Rate and surface roughness of the workpiece are analyzed. The workpiece material parameters, bond properties of abrasive tools surface and processing technical parameters are all discussed. As research result shows: bond yield pressure on the abrasive surface and the Young's modulus have great influence on the number of abrasive particles involved in the processing and cutting depth. With abrasive surface Young's modulus and the bond yield pressure increased, the number of abrasive particles in processing reduces and abrasive cutting depth increases. At the same tine, the surface roughness value becomes greater, and the Material Removal Rate increases/reduces depending on the number of abrasive particles involved in the processing and cutting depth.A semi-fixed abrasive machining experiment is carried out with the optimal parameters and compared with the free abrasive under the same processing conditions. The experiment results show that the removal efficiency is nearly the same in the two kinds of machining technology and the Ra value of workpiece surface machined by semi-fixed abrasives tools is half of which machined by traditional free abrasive. The process performance of surface roughness Ra 8nm, Material Removal Rate 0.12um/min are produced in machining martensitic stain less steel with semi-fixed abrasive tools. It proves the advantage of the machining characters employing semi-fixed abrasive machining. At last, the processing efficiency with semi-fixed abrasive and the workpiece surface roughness values are compared with simulation results, which verify the accuracy of the simulation results.