Surface Environment Effects on Mechanical Properties ofAlumina

Quite a few Rebinder effects in material testing and machining of brittle materials have been realized, however, the mechanism has yet been clarified so far. In addition, there is an important question to be answered concerning Rebinder effect in such conventional brittle materials as ceramic and glass. Measurements of Rebinder effect in nanoindentation, four-point bending tests and single point tool grindings have been made using one of typical ceramic, AhOs. It is found that Rebinder effect was not realized in the bending test using oleic acid as an applied material and such surface treatment as HIP, ozone, heat, and humidification. Applying oleic acid to the AI2O3 test piece provided higher determinations in the bending strength, the nanoindentation hard test and the single-point tool grinding force, which is opposite to Rebinder effect. In addition, the grinding force and nanoindentation hardness were controlled by thickness of oleic acid applied. © 2024 Japan Society for Precision Engineering. All rights reserved.