Abstract
The thermal deformation of a grinding spindle has direct effects upon the quality of machined parts. The final solution is the use of zero-thermal-expansion glass-ceramics as a spindle material to reduce the thermal effects, though there are three problems such as the material cost, machining cost and risk of spindle failure. The ultra-precision surface grinder having a glass-ceramic spindle of zero-thermal-expansion has been built in 1985 and had gotten world-class special results for many years. The spindle has been damaged during operation and a damaged part has been observed. All cracks are originated from ground holes in the glass-ceramic spindle. From the results of bending tests on variously finished zero-thermal-expansion glass-ceramic samples, it is clarified that final finishing process after etching produces higher resistance for the breakage of a glass-ceramic spindle.
