Effect of Grinding Variables on Strength of Hot Pressed Silicon Nitride

Abstract

An experimental study was conducted to evaluate the effect of several grinding variables on the room temperature strength of Norton NC-132 hot pressed silicon nitride. The grinding variables studied included diamond grit size, diamond concentration, type of diamond bond, downfeed rate and type of cut. Significant effects on strength were noted for all variables except diamond concentration.

Ceramic machining

“…The effect of grinding variables on the strength of hot-pressed silicon nitride was also studied by Allor and Baker [1983]. They obtained the same grit size effect observed by Thomas et al that is, the strength was higher at 320 grit than at either larger or smaller grit sizes.…”

“…The latter method, although less satisfactory than evaluation of the actual component, has been used in several investigations to study the effect of machining variables [Allor and Baker 1983, Thomas et al 1987aand 1987b, and Matsuo et al 1987. Recently, this approach has achieved a high level of significance with the issuance of ASTM CI Figure 24.…”

On the fractographic analysis of machining cracks in ground ceramics

“…Parallel [5,76]; and Thomas et al [25]. Others have shown it is not a major factor: Ota and Miyahara [19]; Mayer and Fang [21,22]; Xu et al [5,76]; and Allor and Baker [14,15]. Diamond concentration, diamond bonding (metallic, resiniod, etc), and even operator skill and experience [14,15] all contribute to variability.…”

“…Others have shown it is not a major factor: Ota and Miyahara [19]; Mayer and Fang [21,22]; Xu et al [5,76]; and Allor and Baker [14,15]. Diamond concentration, diamond bonding (metallic, resiniod, etc), and even operator skill and experience [14,15] all contribute to variability. Allor and Baker [15] showed that it is crucial to ensure that a machine shop Of course, the above model was developed for materials with constant fracture toughness.…”

“…) or rectangular beam specimens (e.g., [12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27] uncommon for a fractographer to readily find a fracture mirror centered on a surface origin location, but not find an obvious defect at the origin. This has led some fractographers to guess that the origin must be machining damage.''…”