High speed end-milling characteristics of pre-sintered Al₂O₃/Y-TZP ceramic composites for dental applications

Abstract

Yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP) ceramics have been utilized as a restorative dental material. Pre-sintered Y-TZP ceramics are machined using the Computer-Aided Design and Computer-Aided Manufacturing (CAD/CAM) techniques. In this study, pre-sintered 3 mol % yttria-stabilized zirconia (3Y-TZP) bioceramics reinforced with Al₂O₃ particles were prepared by sintering at relatively low temperature. The machining characteristics of the developed 3Y-TZP composites were investigated using an end-milling process. A series of experiments were performed on a high speed spindle with several sensors: a tool dynamometer, an acceleration sensor, and an acoustic emission sensor. The tool dynamometer was installed below the work-piece, a three-axis acceleration sensor was installed on the spindle head, and the acoustic emission sensor was installed on the fixture. The machining characteristics of the composites material were evaluated in a high speed machining process under various cutting conditions by changing the cutting speed, depth-of-cut, and feedrate. The machined surface was investigated using SEM photographs.