Influence of processing condition of Ti, Al, and B₂O₃ mixed powders on the preparation of Al₂O₃–40.5 mass % TiB₂ sintered compact by HIP

抄録

The Al₂O₃–TiB₂ sintered compact was synthesized by a reaction, Ti + 2Al + B₂O₃ = Al₂O₃ + TiB₂, during hot isostatic press (HIP) with mixed powders of Ti, Al and B₂O₃ as starting materials. It was found that pre-cooling at −5°C and milling at 0°C suppress the reaction to proceeding mechanochemically, and extend the time for mixing. Scraping off clung powders inside of container during the milling made powders fine and uniform. The longer milling time and uniformity of the powders achieved by the above treatments made it possible to obtain Al₂O₃–40.5 mass % TiB₂ with 99.5% relative density and Hv = 2800.