Periodic Layered Structure Formed during Interfacial Reaction

A review of the periodic layered structure (PLS) formed during reactive diffusion was presented. The formation of PLS is a very interesting and complex phenomenon during the reactive diffusion process. It was firstly discovered occasionally. The formation of PLS has been reported in various solid state diffusion couples such as Zn/Ni3Si, Mg/SiO2, Zn/Cix Tiy and so on, and some controversial theoretical models and formation mechanism of PLS were put forward. However, there have been few reports about the PLS formed during hot dip. The development of PLS was reviewed, and the recent progress referring to the formation of PLS during the hot dip aluminizing of a novel Fe-Cr-B cast steel was especially introduced. However, not all of the borides could form PLS in their interfacial reaction with molten Al. PLS only formed at the Cr-rich Fe2B/Al interface, while Mo-rich Fe2B fractured. A general qualitative description for the interfacial reaction of Fe-Cr-B cast steel with molten Al was represented. Further investigation on the constituents of the alternating phases and formation mechanism of PLS needs to be done. At last, the development trends of PLS were proposed.