The Preparation And The Analysis Of Wear Mechanism Of Single Crystal Diamond Tool In Cutting Magnesium-Aluminum Alloy

First, this paper combines with the certain theoretical knowledge, designs and optimizes the process parameters of the cutter, which mainly includes the basic parts of the cutting tool,the selection of proper cutting angle of the cutter, the reasonable choice of geometry parameters of the cutting tool and the crystal shape and characteristics of single crystal diamond. It laid a theoretical basis for the preparation of cutting tool. Then, according to the existing condition of the school and the enterprise, the process of single crystal diamond cutter is designed and the cutting tool is prepared. The main production process is divided into five parts: choosing material, directional, the cutting and coarse grinding of tool rod, brazing,the coarse grinding, fine grinding and inspection of the cutting tool. And in the process of preparing tools, the brazing temperature and constant temperature time were studied, which determines the best technology of the brazing for brazing temperature 850 ℃, constant temperature time of 15 min.In order to study the wear mechanism of the single crystal diamond cutter after cutting magnesium alloy, this paper designs orthogonal experiment including three factors and three levels. The three factors respectively is refers to the rake angle of cutting tool, spindle speed,and feed. According to orthogonal experiment table, nine experiments were carried out. After each cutting, single crystal diamond cutting tools were detected before and after cutting through vertical microscope. The topography figures of cutter surface wear were gained, and the surface roughness of the processed material and the width values of cutter surface wear were measured. The result of the orthogonal experiment can be made range analysis, which can learn in the single crystal diamond cutter cutting magnesium alloy, the spindle speed has a significant effect on the surface roughness of the processed material. Surface roughness increases significantly with the increase of the cutting tool rake angle and feed, and at the time of the more than 3000 r /min speed, the surface roughness is also on the rise. And the main influencing factors on tool wear is rake angle of cutting tool, the second is spindle speed,the last is feeding. In the cutting process of diamond tool, tool wear volume is as small as possible, so when the single crystal diamond tool cuts magnesium alloy, the optimal process parameters combination of the smallest tool wear is rake angle 10°、spindle speed 3900 r/min、feeding 0.1 mm/r。When the single crystal diamond tool cuts magnesium alloy in the optimal process parameters combination, through analyzing the wear morphology characteristics of the cutter blade surface, it is found that cutting tool has a mild wear and accompanies by signs of the dissociation and fracture wear. The tool rake face has wear scratches, and form the micro grooves and the gap of damage. This shows that the main wear form of cutting tool is mechanical friction wear.