The interaction of titanium and titanium alloys with nitrogen at elevated temperatures. II. The nitridation behavior of alloys containing 5 weight percent of aluminum or chromium

The nitridation behavior of a Ti-5Al and a Ti-5Cr alloy has been examined at 1000°C and compared with the performance of pure titanium, involving gravimetric, metallographic, and microhardness studies. All of the materials corrode in accordance with a parabolic overall weight gain-time regime, pure titanium nitriding faster than either of the alloys. The reduced rates of nitridation of the alloys relative to pure titanium are reflected in the smaller relative depths of nitrogen dissolution in the substrates and may be accounted for by the corresponding decreased diffusivity values for nitrogen. The addition elements appear to play no part in the linear scaling reactions.