Patent ID: 6468366
Filing Date: 2002-10-22
Classification: C23C

Abstract:
A surface nitriding member comprising a substrate made of metallic aluminum, aluminum alloy or aluminum-containing composite material, and a nitriding portion formed by nitriding a surface portion of the substrate, wherein the nitriding portion contains at least one element other than aluminum selected from Group 2A, Group 3A, Group 4A and Group 4B in Periodic Table and wherein (1) a concentration of the element at a surface side of the nitriding portion is lower than that of the element at a substrate side of the nitriding portion, (2) the concentration of the element in the nitriding portion is varied stepwise from the substrate side to the surface side, (3) the nitriding portion comprises a high concentration region positioned at the substrate side thereof in which the element is contained at a high concentration and a low concentration region positioned at the surface side thereof in which the element is contained at a low concentration, and (4) a concentration of the element in the low concentration region is not more than 0.5 wt %.