出典:Wikipedia
出典:『Wikipedia』 (2011/03/18 00:06 UTC 版)
In metallurgy, alpha case is the oxygen-enriched phase that occurs when titanium and its alloys are exposed to heated air or oxygen. Alpha case is brittle, and tends to create a series of microcracks which will reduce the metal's performance and its fatigue properties. Alpha case can be avoided by processing in a vacuumed environment, but, due to its costs it is usually eliminated via machining or chemical milling.