Experimental Study On Micro-structuring Coarse-grained Bronze-bonded Diamond Grinding Wheels By Using A Short-pulsed Laser

Diamond grinding wheels were widely used in the grinding of hard brittle materials. Fine-grained diamond grinding wheels can obtain high surface quality of workpiece during grinding, but encounters problems of low grinding efficiency and more dressing frequency. High grinding efficiency can be obtained by using of coarse-grained grinding wheels, while the surface quality of workpiece is relatively poor. Exploring new technology of structuring coarse-grained grinding wheels, and achieving high efficiency and high quality grinding technology of coarse grained grinding wheel have broad prospects for development and Application. Given this, an experimental platform which takes the pulsed ultraviolet laser as the light source was designed and established in this thesis. And t he platform can be used to realize micro-structured test on the surface of bronze diamond grinding wheel. The pulsed ultraviolet laser micro-structuring of 60# bronze-bonded diamond grinding wheels has been systematically studied using the method of laser processing which based on the principle of laser ablation. The detailed description is listed as follows:(1) The selection principle of the width and depth of micro-structuring grooves on the surface of 60# bronze-bonded diamond grinding wheels was analyzed. The effects of laser power density, laser path number and distance, laser spot overlap rat io and number of laser scanning cycles on the grinding wheels by micro-structuring were studied. The results show that higher micro-structuring efficiency can be obtained by increasing the laser power density. The laser path number and distance play key roles in the width of micro-structuring grooves. The quality of the micro-structuring groove bottom of the grain will be affected by the laser spot overlap ratio. And th e depth of micro-structuring grooves is related to the number of laser scanning cycles.(2) The influence of width and depth of micro-structuring grooves on the formation of micro-structuring grooves was analyzed. The smaller the groove width, the more slowly increases of the groove depth, the slower formation speed of the groove when the groove depth is consistent. The larger the groove depth, the slowly increased of the groove depth and the slower formation speed when the groove width is consistent.(3) A comparison experiment of the laser micro-structuring groove density and groove angle was carried out. The state of diamond abrasive particles on the surface of the grinding wheel with different groove densities was observed. The surface roughness of the workpiece was compared with the different groove angle. The results show that too small or too large micro-structuring groove density can cause the increase of the ratio of bad micro-structuring diamond grains. The best groove density is 27.5% under the conditions of this experiment. The workpiece have a poor surface quality when the groove angle was 0° or 90°.(4) Two micro-structuring grinding wheels with different surface patterns were prepared. The comparison experiment of grinding with the non-structuring diamond grinding wheels was carried out which the YG8 cemented carbide as a work piece. The results show that the surface of the grind ing workpiece is more uniform by using laser micro-structuring diamond grinding wheel. Therefore the micro morphology is better and the surface roughness of the workpiece is lower. While the abrasion resistance of the grinding wheels was reduced to a certain extent compare with the non-structuring diamond grinding wheels.