Fractographic Analysis of Machining Cracks in Silicon Nitride Rods and Bars
George D. Quinn, L K. Ives, S Jahanmir, P Koshy
A new fixture for flexural strength testing was used to evaluate the effects of machining on the flexural strength of a toughened sintered reaction-bonded silicon nitride. Different grinding procedures had various effects upon the flexure strength distributions. These effects were directly related to the size and severity of fractographically-measured machining cracks. Under certain conditions, grinding caused negligible damage and the specimens fractured from intrinsic material flaws.