BONDED ALUMINA COATING FOR STAINLESS STEEL

摘要

A method for manufacturing an alumina-based layer structure having transition regions between layers is disclosed. The method may include ion milling a stainless steel structure surface to partially reduce a metal oxide layer from, and create an exposed portion of, the surface. The method may include oxidizing the exposed portion of the surface to form a crystallized metal oxide bonding layer, growing a crystallized alumina layer onto the metal oxide bonding layer, and diffusing metal from the surface into the crystallized alumina layer, to form a graded aluminate spinel layer. The method may include forming a first transition region from the graded aluminate spinel layer to a crystalline alumina layer, growing the crystalline alumina layer from the first transition region, forming a second transition region from the crystalline alumina layer to an amorphous alumina layer, and growing the amorphous alumina layer from the second transition region.

主权项

1. An apparatus comprising:
a stainless steel structure; an at least partially polycrystalline alumina-based layer structure bonded to an exposed portion of the stainless steel structure, the layer structure including:
a crystallized metal oxide bonding layer formed on the exposed portion of the stainless steel structure;a graded aluminate spinel layer formed on the crystallized metal oxide bonding layer, the graded aluminate spinel layer having:
metal diffused from the stainless steel surface; andan at least partially polycrystalline structure;a crystalline alumina layer;a first transition region extending from the graded aluminate spinel layer to the crystalline alumina layer;amorphous alumina layer; anda second transition region extending from the crystalline alumina layer to the amorphous alumina layer.