The Study On The Processing Method For Machining Of Diamond By Utilization Of The Wear

Diamond is a kind of unique material with special mechanical, thermal, optical and electrical properties, and it has been widely used in more and more fields. Almost all the diamond parts need to be processed into required dimension and structure, so how to efficiently process the desired diamond part with high quality and low cost has become a hot academic point. Currently, the exsiting methods for cutting diamond include: Chemical Vapor Deposition(CVD), etching, and polishing, but all of them have some shortcomings such as low efficiency, complex process and high cost etc., so it needs a new method for processing diamond to overcome the shortcomings.As we know, the diamond tool will be severe worn at high temperature and pressure when it cuts the ferrous material, so it will be feasible in theory that the diamond could be processed via the wear by using the ferrous material as the “cutting tool”.This paper studies a new kind of method for machining diamond via the wear by utilizing the ferrous material, so as to finally obtain the required dimesion and the structure of the diamond parts. Therefore, this paper has made a preliminary and basic applied research on the“wear machining of diamond”, and the main contents are as follows:1. Introduce and dicuss the current methods for machining the diamond workpiece, such as CVD, etching, and polishing etc., and talk about the abrasion mechanism and control methods of the diamond tool, as well as the research effort of both Prof. Nakamoto and Prof. Brinksmeier.2. Analyzing the process of the wear machining of the diamond via the Molecular Dynamics(MD). Propose the definition of the“surface texture”and discuss its“size effect” on the process of the wear machining of diamond, the surface texture depends on both the atom size of the workpiece material and the surface roughness. The“size effect” of the surface texture on the process would be more obvious, if the surface is more rougher; Analyzing the lattice change in both the diamond workpieces and the ferrous material as well as the change of the cutting force, and the material removal mechanism has been revealed according to the analysis; The effect of the cutting parameters on the process has been discussed by changing these parameters through the MD simulation.3. Develop a measuring device for measuring the cutting output of the embedded micro part, and this device can be used to measure the amount of the material removal of the diamond workpiece, and the material removal rate per unit time can be calculated. Propose the measuring principle of the measuring device through measuring the change of the displacement. Develop or choose the components of the device, and conduct the finite element analysis on the key componets of the device, so as to prove the rationality of the design. The device has been tested after the building the measuring system, and the result proves that the measure device is capable of measuring the cutting output of the diamond workpiece.4. Investigate the influence factors and laws of the process of the wear machining of diamond, maily for the effect of the cutting parameters that include the revolution of the ferrous material, the feed and the cutting depth and different ferrous material on the material removal rater of the diamond workpiece, the cutting force and the surface roughness. The influence of the revolution of the ferrous material on the material removal rate of the diamond workpiece is very significant, when use the 45# steel as the cutting tool and the revolution is 1000r/min, the material removal rate of the diamond workpiece is small enough, only 0.001mm/min, but when the revolution increases to 2000r/min and 3000r/min, the material removal rate can reach to 0.037mm/min and 0.059mm/min. In order to avoid breaking the diamond workpiece, the feed and the cutting depth should be chosen small value; The material removal rate of the diamond workpiece by using the 20# steel, the 45#steel, and the T10 steel have been compared, and the results show that the diamond workpiece can not be cut by the 20# steel, and the T10 steel is only applicable to the operation condition of the small cutting depth(dc=0.01mm), and its material removal rate is a little lower than the case of using 45# steel whose cutting depth is 0.03mm; the cutting force is obvious cyclical change, and the numerical value of the periodic time is equal to the value of spindle rotation frequency, it means that the cutting force depends on the geometric accuray of the spindle; the surface roughness of the diamond workpieces that were processed by both the 45# steel and the T10 steel have been observed, and the surface roughness of the diamond workpiece that cut by the T10 steel is a little better than the one that were cut by the 45#, because of the samller cutting depth when using the T10 as the cutter. The results prove that the surface quality of the diamond wokrpieces would be improved, if increaseing the cutting times.5. Investigate the effect of the substance that contains the hydrogen atom(s) on the process of the wear machining of diamond. The water vapor and the H2O2 have been chosen as the material that would be put into the cutting area duting the process, according to the diffencet properties of the substance that contains the hydrogen atom(s). The results show that the material removal rate of the diamond workpiece will increase a lot when a large amount of water vapor with high temperature is continuously injected into the cutting area, i.e. the substance that contains the hydrogen atom(s) can impove the material removal rate of the wear machining of diamond. When the water vapor is injecting into the cutting area, the material removal rate of the diamond workpieces are separately 0.004mm/min, 0.051mm/min and 0.082mm/min, when the revolution of the 45# steel are respectively 1000r/min, 2000r/min and 3000r/min, and compare with the case that without putting any other substance into the cutting area, the material removal rate of the diamond workpice respectively increase three times, 37.84% and 38.98%. Meanwhile, the surface roughness also decreases to 0.468μm. The effect of a small amount of H2O2 on the material removal rate of the diamond workpiece is very weak, and whether a large amount of H2O2 has an obvious influence on the wear machining process needs further investigation.This paper can provide the basic process theory to the wear machining of diamond, can provide the basic methods to increase the material removal rate of the diamond workpiece, and can give the processing of diamond material a new method with high effiency and low cost. It innovatively makes a significance to solve the problem of machining of diamond.