Grain-size effects on multi-wire slurry sawing of translucent alumina ceramics

The technology of multi-wire sawing is well established in the production of silicon wafers, but can also be applied in the production of ceramic substrates. In this study, the influence of the Al2O3-grain size of the alumina ceramic on the efficiency of the multi-wire slurry process was investigated. The grain size of HIPed alumina ceramics was changed by a heat treatment processes at 1350°C and 1400°C. A B4C slurry was used for the investigation of the cutting of high purity Al2O3-ceramic by the multi-wire slurry process. With increasing grain size of the ceramic the efficiency of the sawing process increases. The analysis of the as-cut surface morphology of the substrates shows a change in material removal from trans- to intergranular micro-fracture with increasing grain size. Furthermore, grain coarsening leads to substrates with increased roughness values and reduced biaxial strength.