Precision Grinding of Micro-structures of Hard-Brittle Material Surfaces

Abstract

In this chapter, in view of the low processing efficiency and accuracy of hard-brittle material, a precision-trued V-tip diamond grinding wheel is proposed as the means to fabricate regular micro array structures with high surface quality and controllable form accuracy on the surfaces of those difficult-to-machine materials. First, a V-shaped tip diamond grinding wheel with sharp micro-grain cutting edges was obtained by mechanical truing along V-shaped cross interpolation trajectories. Four typical hard-brittle ceramics and ceramic-matrix composite materials including monocrystalline silicon carbide, aluminum-based silicon carbide, reaction sintered silicon carbide, glass ceramics were selected as the workpiece materials. The trued V-tip diamond grinding wheel was employed to machine the micro-groove and micro-pyramid array structures on the surfaces of ceramics and ceramic-matrix composite materials. Finally, the micro-ground surface and 3D topographies, micro-groove profile, tip arc radius, tip angle and form accuracy were analyzed and investigated for four different materials. The experimental results show that the arc radius at the bottom of micro-groove on the surface of monocrystalline silicon carbide, aluminum-based silicon carbide, sintered silicon carbide and three kinds of silicon-carbide ceramics is close to 21 μm while the difference is less than 1 μm, the difference between the tip angle and the theoretical angle of 60° is less than 1°, and the shape-accuracy error can be controlled within 15 μm. It can be seen that micro-grinding hard-brittle material such as ceramics and ceramic-matrix composite can ensure high machining accuracy.