Basic Research On NC Contour Evolution Ultrasonic Grinding The Surface Of Ceramics

Ceramics has become the third engineering material, for its excellent performance of mechanics, physics,chemistry and calorifics. Because of its high brittleness and high rigidity, there are many difficulties in machining, especially forming processing, which limits its using in engineering. Ceramics is the ideal material to manufacture small integral impeller of aeroengine, aerospace engine and automobile engine in future, in order to solve the problem of machining ceramics integral impeller, basic research on NC contour evolution creep feed ultrasonic grinding ceramics surface was conducted, the main research work includes:1 ) The mode of the maximal undeformed chip thickness was constructed at the condition of small grinding wheel, big cutting depth and creep feed. Comparative experiments of grinding ceramics with/without ultrasonic vibration were carried out, grinding parameters's effectiveness on surface roughness(Ra) and actual depth was studied. Surface topography was studied by SEM. The experimental results have shown that ultrasonic vibration can increase actual depth remarkably and increase Ra slightly, but it would not cause dangerous subsurface damages. The material was removed mainly as brittle fracture mode followed with plastic flow.2 ) In order to satisfy the requirement of NC ultrasonic grinding parallel ruled surface, based upon the original 5-axis NC electrochemical contour evolution machining machine tool, the grinding spindle assembly and its driving system were developed, moreover, ultrasonic vibration system and indexing mechanism were added, thus NC contour evolution ultrasonic grinding device was made, the device can be used to machine blade surface of ceramics integral impeller. The real-time multi tasks system based on DOS—the software design of spindle's variable frequency and variable speed system was developed.3 ) The mathematical model of parallel and undevelopable ruled surface was constructed, the algorithm for NC ultrasonic grinding surface was founded. Based on this algorithm, a automatic programming system was developed by means of mixed programming with Visual C++ and Matlab.4 ) Experiments of NC ultrasonic grinding ceramics surface were performed, circular arc groove was machined on ZrO2 ceramics block, ruled surface was machined...