Laser Assisted Machining of Ceramic Parts with Complex Features

Purdue University, West Lafayette IN

Investigators

Abstract

This project seeks to theoretically and experimentally establish a scientific basis for laser assisted machining (LAM) of various structural ceramic materials, which can significantly reduce the fabrication costs and improve end-state properties for ceramic parts. Theoretical treatments of LAM processes will be used to determine the thermo-mechanical behavior of ceramics during LAM, by developing thermal models, temperature dependent properties of the materials, constitutive models and process simulation models. Supporting experiments will be performed to characterize machining performance in terms of sub-surface damage and surface finish of machined specimens, tool wear and maximum material removal rate. The feasibility study with silicon nitride parts demonstrated the capabilities of LAM by achieving long tool life of approximately 40 minutes, surface finish commensurate with those of grinding and little sub-surface damage cracks and heat affected zone as well as significantly higher material removal rates than grinding under nominal machining conditions. Based on this successful feasibility study, laser assisted turning processes will be expanded to machining of various important structural ceramic materials such as silicon carbide (SiC), alumina (Al2O3), mullite, zirconia (ZrO2) and silicon nitride (Si3N4). In particular, the proposed research seeks to develop the capability to fabricate parts with complex geometry by developing requisite in-process monitoring and control techniques. This will lead, along with the developed modeling capabilities, to facilitating the implementation of LAM in industry.