Evaluation of microwave-sintered titanium and titanium alloy powder compacts

Titanium (Ti) has many attractive attributes for naval applications including high strength, no magnetic signature, and excellent corrosion resistance; however, its use has been limited by high costs. Microwave sintering of titanium powder compacts can potentially lower the cost of titanium parts. This approach benefits from recent low cost metal-from-ore production methods that produce powder instead of sponge. Current experiments utilize an over-moded, variable atmosphere, S-Band processing chamber and are evaluating the optimum preform density and microwave processing conditions for consolidating titanium powder into complex, near-net-shape parts. These experiments indicate that microwave sintering leads to shorter processing times and lower processing temperatures compared to the processing in a conventional furnace. As-received commercially pure titanium powder was also milled to reduce particle size in order to improve densification but it did not improve the densification of the sintered product. The asreceived pure titanium alloy (Ti-6Al-4V) achieved higher densification compared to the asreceived pure titanium powder with similar particle size.