Brazing Diamond Grinding Wheels With Ultra-high-frequency Induction

With obvious advantages in aspects of the exposing height of abrasive grains, the grinding forceand the grinding wheel’s life, the monolayer brazed diamond tools are widely used in the processingof hard and brittle materials. At present, there are mainly two methods for preparing brazed diamondtools: vacuum furnace brazing and induction brazing. Each of the two processing methods has itsunique advantages and application field. However, they also have some inevitable disadvantages andlimitation. Based on the research on the existing brazing methods, the method for preparing diamondtools by using ultra-high-frequency induction is proposed in this subject. It may further extend themethods for brazing diamond tools due to a high heating speed, a small heating area and a flexibleheating manner of the ultra-high-frequency induction brazing.The main contents in this project are as follows:(1) The coil heating manner and the ultra-high-frequency induction heating equipment have beendetermined through the analysis of the ultra-high-frequency induction processing. The design of theinduction heating coils and the magnetic conductor has been completed. The experimental resultsshow that its performance meets the requirements. The scope of optimized ultra-high-frequencyinduction heating parameters has finally been determined by researching, through temperature tests,the influence of the heating processing parameters on the heating temperature.(2) Through diamond brazing tests of different processing parameters, the optimizedultra-high-frequency induction processing parameters are finally determined. The interface analysisresults show that: the filler alloy show good infiltration to the diamond; and grainy or island-shapedTiC crystals are formed on the surface of the diamond abrasive grains and are discretely distributed onthe surface of the diamond abrasive grains. Due to the rapid brazing process, small grains of the filleralloy layer are obtained after the brazing, and further a dendritic crystal structure can be seen in aportion of the filler alloy layer, thereby improving the holding force applied to the diamond by thefiller alloy.(3) The device for preparing successive ultra-high-frequency induction brazing diamond grindingwheels has been produced. The diamond grinding wheel with a diameter of Φ400mm and havingabrasive grains arranged in a sequence has been made by using the optimized processing parameters.The deformation of grinding wheel matrix is small and the working surface topography is in goodcondition. (4) Experiments of grinding SiC ceramics are conducted. The grinding force is relatively small; noobvious change in the surface of the grinding wheel is observed after the grinding; only slight attritionis observed on cutting edges of a small amount of grinding abrasive grains; and no grinding abrasivegrain broken or dropping of a whole abrasive grain is observed. The abrasive grains of the grindingwheel are sharp and the bonding strength between the filler alloy and the diamond is very high.