Research On Drilling Of Hard Engineering Ceramic By Brazed Diamond Boring Tool

With the rapid development of manufacturing and modern industry, there is that one increasing demands for Engineering ceramic materials in varies fields. And a higher quality is demanded refer to the machining of the Engineering ceramic materials. In this paper high temperature brazed diamond drills were prepared and used to bore Silicon carbide and alumina. The characteristics of tool's wear and failure in the boring were observed and analyzed. A comparison of machining efficiency, lateral grinding force and wear characterist-ics were made between Silicon carbide and Alumina engineering ceramic materials machined by the drill with different mesh size diamond grits. The grinding force, processing efficiency and hole quality under the different condition of coolants were also studied. The results are summaried as follow:The efficiency of the tool with coarse 30/40 mesh is higher than that of 40/50 and 50/60 mesh.The boring efficiency of the tool on Silicon carbide is lower than that of alumina. Lateral grinding force increased with the increase of the spindle speed and feed rate. Lateral grinding force of Coarse-grained tool is larger than Fine-grained tools. However, Lateral grinding force of that of Fine-grained tool is more stable. Lateral grinding force during the boring of Silicon carbide is larger than that of alumina. The Roughness of the hole is increased as the increase of the diamond mesh size. The hole quality is poor when using coarse diamond grit. And the hole quality of Alumina is better than that of silicon carbide.The machining efficiency of the tool is higher when using Op10 and 1631 as the coolants than that of water. Also the efficiency is increasing as the concentration of the coolant is increased. Lateral grinding force is also reduceed and remained stable. The tool's lateral grinding force is decreased with the addition of the Op10 and 1631 coolant,and the increasing of the concentration of the coolant. Under the same concentration, the influence of 1631on boring is a bit larger than that of Op10. The wear level of brazed diamond tools in different size is different. The wear of Coarse-grained tool is greater than that of the fine-grained tool. The grinding ratio increases when using Op10 and 1631 coolant. The grinding ratio of the tool on Alumina is larger than that of silicon carbide. During the boring progress of the engineering ceramics, material removal mechanisms are brittle removal and plastic removal. The main material removal method is brittle removal. And the main wear mode is fracture, With the increasing of the boring time, the wear is severer.When the tools are failed,large number of diamond grit were worn with flat surface, some of diamond grits were pulled out. The wear of the tool in boring Silicon carbide is more severer than that of the Alumina.