Research On Mechanical-chemical Edge Preparation Process For Nature Diamond Tools

Natural diamond tools play an important role in the field of ultra-precision machining.At present,the main manufacturing method of natural diamond tools is still mechanical grinding method,which has high processing efficiency,but the diamond tools manufactured often have micro defects,such as breaking cutting edges,micro-grooves on the tool surface.The cutting edge strength of tens of nanometers or even less formed by mechanical grinding of diamond tools is also low,the impact resistance of diamond tools in cutting is poor,and the cutting performance is not satisfying.The cutting stability is poor.In addition,the micro-damage layer on the tool surface is easy to expand.The diamond tool will wear quickly and form a large gap on the cutting edge,which leads to the early failure of the tools,and the diamond tools can not continue to use.Therefore,the research of new edge preparation process for natural diamond tools is the key to obtain excellent cutting edge.The main research content of this subject is to prepare the cutting edge of arc-edged natural diamond tools by mechanical-chemical method,so as to obtain high quality arc-edged natural diamond tools with no defects,good cutting edge consistency and high strength cutting edge.The main research contents are divided into three parts:the mechanism of mechanical-chemical edge preparation of natural diamond tools,and the process research of mechanical-chemical edge preparation of natural diamond tools,and the cutting performance of natural diamond tools before and after edge preparation.Firstly,a mechanical-chemical edge preparation method is established,and the data processing method for the cutting edge of diamond tools is determined.According to the basic experimental results,the evaluation index of the cutting edge shape of diamond tools is established.The chemical mechanism of mechanical-chemical edge preparation process was analyzed and validated by preliminary experiments.According to results of the pre-experiment,considering that the mechanical-chemical edge preparation method is still dominated by mechanical action,the micro-tensile strength of the plane on the edge surface of natural diamond tools was deduced,and the edge preparation experiment was carried out.And the experiment results proved the correctness of the theory.Then,the mechanical chemical edge preparation process method of natural diamond tools was studied by using the established mechanical chemical edge preparation process system.The influence of spindle rotation direction,edge preparation time,spindle angle and spindle speed to the edge preparation quality were mainly studied.Combining with the edge shape parameters,the causes of the correspondingchanges were analyzed by using the theory of micro-tensile strength of the edge surface.The optimum combination of edge preparation process parameters is determined.By using the optimum combination of edge preparation parameters,a high edge preparation rate can be obtained.Finally,the changes of cutting performance before and after edge preparation of natural diamond tools were analyzed,including the influence of wedge angle,radius of cutting edge and edge defects to the cutting performance.The cutting performance experiments of the tools prepared by mechanical-chemical edge preparation process were carried out.Three natural diamond tools are used which the conditions are non-edge-prepared,edge-prepared with the cutting edge radius of 67 nm and 120 nm respectively.The improvement of cutting performance to the edge-prepared diamond cutting tools was studied by cutting experiments.