Process for forming a superficial layer having a high hardness by plasma-free thermochemical treatment

摘要

A hard surface layer is formed on a piece of alloy which is reactive with nitrogen, oxygen or carbon, such as titanium or zirconium, by heating the piece to over 650 degrees C in an enclosure where the pressure is no more than 0.1 mbar, then injecting a suitable reactive gas but still maintaining a pressure below atmospheric for a period between a few tens of minutes and 24 hours or more, depending on the layer thickness required.