Gas corrosion resistance and as a Al alloy and the semiconductor production device material charge null alloy component which for the semiconductor production device are superior in alumite membrane formation characteristic and

摘要

PROBLEM TO BE SOLVED: To obtain an Al alloy capable of forming alumite coating excellent in corro sion resistance to gas and plasma and heat-resistance by allowing the alloy to have a specified compsn. contg. Mn, Cu, Fe, and the balance Al with inevitable impurities and furthermore regulating the average grain size in the structure to specified value or below. ;SOLUTION: The compsn. of the Al alloy is composed of, by mass, 0.3 to 1.5% Mn, 0.3 to 1.5% Cu, 0.1 to 1.0% Fe, and the balance Al with inevitable impurities. Then, the average grain size in the alloy structure is regulated to ≤50 μm. On the surface of the Al allay, alumite coating is formed by anodic oxidation. At this time, an alumite layer having a porous layer excellent in corrosion resistance to gas and plasma and heat resistance and a barrier layer free from pores is preferably formed. In this way, stress and the volume change generated in the case where it is brought into contact with corrosion gas such as halogen and plasma are relaxed, by which the cracking and peeling of the coating causing corrosion and damages can be suppressed.;COPYRIGHT: (C)1999,JPO