The Simulation Of Diamond Tools Drilling Engineering Ceramics And Machining Prestressed Engineering Ceramics

Engineering ceramics have a wide range of industrial applications as its excellent physical, chemical and mechanical properties. However, due to the higher hardness and brittleness, it is difficult to machine. In the core drilling of engineering ceramics, the exit zone and the hole’s wall is quite difficult to control. In order to improve the hole’s quality, in this study we use the monolayer brazed diamond tool to core drill the engineering ceramics with the prestressed condition.Through the finite element we simulate the process of diamond grits scratching engineering ceramics, and studied the effect of the prestress on engineering ceramics.we simulate the process of crack propagation when diamond tools drill engineering ceramics.Taking alumina ceramics as the research object, we do all kinds of drilling experiment through the clamp under different processing conditions and the processing parameters. We analysis of the quality of hole wall and exit zone quality under the different principal plane and auxiliary plane stress. In order to avoid the resonance phenomenon of diamond tools, we determine the frequency of the diamond tool through modal analysis.In the aspect of diamond tool structure, We improve the life of the diamond tool by adding small slot on the bottom surface of diamond tools. Experimental results show that the life of the diamond tool will extend with the increase of slot number.when the number of micro slot is three, diamond nesting drill have a higher life.We studied the influence of feed pressure to the life of diamond tools and machining efficiency. Experiments show that the life of the diamond tool will gradually shorten with the increase of feed pressure, but drilling efficiency will be improved significantly. In addition through the study abrasion mechanism of diamond tools, we found that the variation regularity of diamond grits and the damage process of diamond grits.Research have found that the maximum principal stress of diamond grits is around the sinks, and the farther the location of the sink, the response of stress will be smaller. When diamond grits stress is larger, the stress of the junction also is bigger, the location of the diamond is easy to fall off.