Formation and adhesion of protective oxide layers

The adherence of the alumina film to the alloy is very important. If this layer should spall, the aluminum-depleted alloy layer will be exposed to the oxidizing atmosphere and will generally form the transient oxides, 

Smialek has summarized the sulfur effect [10], which is generally explained in terms of the sulfur segregating to the alloy/oxide interface and lowering the work of adhesion. Sulfijr has been shown to lower the fracture energy of artificial Ni/alumina interfaces from F 100 J/m to r w 10 J/m [11]- A question remains regarding the mechanism of the 

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