Dressing And Testing Of Diamond Arc Wheel For Large Aspheric Mirror Grinding

With the development and application of space science more and morewidely, a higher requirements were putted forward for the space optical deviceand system. SiC were used as the material of space mirror for its good physicalproperties and superior performance. While dressing the large aspheric SiCmirror with diamond arc wheel, the huge grinding quality would lead the changeof wheel radius and edge sharpness, it could not meet the requirement ofmachining accuracy and surface quality for SiC mirror dressing, so it wasimportant for improving the machining accuracy and surface quality of largeaspheric SiC mirror by being sure the methods of dressing diamond arc wheeland the methods of testing the wheel radius and the wheel shape.The EDM (electron discharge machining) dressing and eddy current testingdevice for arc wheel was developed based on the requirement of diamond arcwheel dressing and testing. The methods of testing the arc wheel radius and thearc shape by eddy current sensor were researched based on the characteristics ofthe device, the effect of the frequency parameters on the testing results wereanalyzed, and the value of the frequency parameters were determined. The theorybasis and the Technical support were provided for subsequent experiments.The model of wheel shape dressing by the cup electrode, the error betweenwheel shape and ideal shape and the space between test probe and wheel arcsurface while the space was not constant were built, and the models weresimulated, then the curve of wheel shape after dressing and the curve of the spacebetween test probe and wheel arc surface while the space was not constant wereresearched by model simulation, and the curves were verified in the experiment.The experiments of diamond arc wheel were done, and the effect of the EDMprocess parameters on testing results and the dressing rate of radius wereanalyzed. The effects of peak voltage, pulse frequency, duty ratio and workingliquid on the testing results and the dressing rate of radius were researched, andthe foundations of online dressing and testing technology for arc wheel were laid.