Anodized aluminum alloy material having both durability and low polluting property

Abstract

An anodized aluminum alloy material is formed of an aluminum alloy having a Mg content between 0.1 and 2.0% by mass, a Si content between 0.1 and 2.0% by mass, a Mn content between 0.1 and 2.0% by mass, and an Fe, a Cr and a Cu content of 0.03% by mass or below and containing Al and unavoidable impurities as other components, and is coated with an anodic oxide film. Parts of the anodic oxide film at different positions with respect to thickness of the anodic oxide film have different hardnesses, respectively, and the difference in Vickers hardness between a part having the highest hardness and a part having the lowest hardness is Hv 5 or above.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to an aluminum alloy material and, more particularly, to an anodized aluminum alloy material intended for forming members of the vacuum chambers of apparatuses for manufacturing semiconductor devices and liquid crystal devices, such as CVD systems, PVD systems, ion-implanting systems, sputtering systems and dry etching systems, and those placed in the vacuum chambers.[0003]2. Description of the Related Art[0004]Reactive gases, etching gases, and corrosive gases containing halogen as a cleaning gas are supplied into the vacuum chambers of apparatuses for manufacturing semiconductor devices and liquid crystal devices, such as CVD systems, PVD systems, ion-implanting systems, sputtering systems and dry etching systems. Therefore, the vacuum chambers are required to have corrosion resistance to corrosive gases (hereinafter, referred to as “corrosive gas resistance”). Since a halogen plasma is o...

AI Technical Summary

Benefits of technology

The present invention provides an anodized aluminum alloy with high hardness, durability, and low polluting properties. The alloy has a specific composition and is coated with an anodic oxide film. The film has different hardnesses at different positions, with the highest hardness at the surface and the lowest hardness at the center. This results in improved plasma resistance and makes the alloy suitable for various applications.

Problems solved by technology

However, those properties are still unsatisfactory and further improvement of those properties is desired.

Although the plasma resistance may be improved simply by coating an aluminum or an aluminum alloy material with a hard anodic oxide film, the hard anodic oxide film is liable to crack.

However, such an anodic oxide film is harder, and the crack resistance and durability of such an anodic oxide film are worse.