Parameter Optimization Of Milling Dedicated Diamond Tool For KDP Crystal And Experiment Research

As important optical component, KDP crystals are used extensively in the opticalsystem of large high-energy solid lasers and strong laser weapons. However, itexceedingly difficult to machining due to the high machining quality requirements,anisotropy and soft-brittle of itself. At present, the more mature processing method forKDP crystal machining is the single point diamond turning technology, and themachining quality of KDP crystal is intimately related to the parameters of diamond toolaccording to the research. The high machining quality of KDP crystal is limited, tosome extent, by the diamond tool for KDP crystal machining owing to the expensive ofimported tool and disqualification of domestic tool. Therefore，it is necessary andimportant to carry out the study and investigation upon the fine diamond tool for KDPcrystal for developing new energy and the defense security.Firstly, the relationship of the friction coefficient between diamond and KDPcrystal was researched by the static experiment of friction, including diamondcrystallographic planes and directions, surface roughness of diamond and the load. Thenthe influences of above aspects for machining quality of KDP crystal were analysed.Secondly, the three different KDP crystals were tested by nanoindentation, and theload and unload curves were fitted and analysed after that. Combinded with load-depthcurves, the dimensional analysis method was used to obtain the equations ofstrain-stress of three KDP crystals, accordingly, the corresponded constitutive modelswere created;Thirdly, the finite element model of the KDP crystal machining was analysed bythe finite element software. The results of simulation can be checked after severalmachining, the influences for KDP crystal machining quality including the tool rakeangle, tool clearance angle, tool nose radius，the cutting edge radius and defects on thecutting edge were analysed. Then the parameters of diamond tool were optimized;Finally, for verifying the validity of the simulation, the experiments of KDP crystalmachining were conducted by change the the parameters of diamond tool. Therelationships between surface roughness and some parameters of diamond tool wereobtained through the measure of surface roughness after machining, whichcorresponded well with the finite element simulation results. The paper presented someannouncements during diamond tool grinding based on the internal relationshipsbetween diamond tool and the machining surface roughness of KDP crystal.