Aluminizing

Aluminizing is a thermochemical treatment of metallic materials , mostly steels. The aim of the treatment is an aluminum coating . The underlying physical-chemical process is diffusion , which is implemented in two variants. The calorizing takes place at temperatures around 450 ° C in a container filled with aluminum powder reactor instead. A subsequent brief annealing at temperatures around 750 ° C outside the reactor increases the diffusion. The result is a hard Al ₂ O ₃ layer under which a brittle intermetallic Fe-Al layer with Al concentrations above 10% is formed. With alternative aluminizing , annealing takes place at 800 ° C to 1200 ° C in an Al-Fe powder. The protective layer achieved is more malleable, less brittle and also resistant to scaling .