Processing of Titanium and its Alloys by Microwave Energy

Microwave sintering of titanium and its alloys is a recent development in powder metallurgy of titanium. The sintering in an atmospheric pressure argon gas environment or vacuum is potentially cost effective and energy efficient compared to conventional sintering methods due to the possibility of direct microwave heating of the titanium powder via in-depth energy deposition augmented by hybrid heating in a ceramic casket. The in-depth heating permits very rapid processing (cycle times of potentially less than 10 minutes) which is intended to preserve a very fine grain structure in the final product resulting in excellent mechanical properties and the possibility of superplastic forming. We are investigating this approach using an S–Band microwave system. The process can be also used for composites, laminates, direct alloying, and functionally gradient materials. Evaluations to optimize different parameters for controlling the final density, microstructure, and properties of these materials are underway and results are discussed.