Laser-Assisted, Ultra-Precision Manufacturing of Polycrystalline Alumina

Creare’s overall objective is to develop and transition a technology that will enable the single-point diamond turning of super-hard ceramics into optical quality missile ogives. Aerodynamic missile ogives will offer a less restricted view than traditional hemispherical optics and reduce drag. To this end, we will develop a novel, laser-assisted, pre-finishing system. During the Phase I project, we successfully demonstrated on a conventional machine tool that our innovative approach can cost-effectively machine polycrystalline alumina with large regions of plastic flow and with no sub-surface damage. We expect to improve upon these results during the Phase II project. Specifically, we will integrate our novel approach with an ultra-precision machine tool to further improve the surface quality of the machined part. We will provide superior performance control using a model-based adaptive controller to precisely control the temperature of the ceramic material near the cutting edge. In doing so, we will create a machined surface that is free of any surface or subsurface damage and that is prepared for optical finishing. The high material removal rate enabled by our innovation allows much higher sintered part tolerances compared to current finishing options; thus, our innovation will have indirect benefits by reducing the cost to sinter the near-net shape blank. In summary, our innovation is effective, affordable, and flexible.