engleski

Novelty in Diffusion Coating Technology

Diffusion forming of a hard carbide layer has been used for many years, mostly in Japan (Toyota Diffusion Process, TDR) and in the USA (Thermoreactive Deposition, TRD) but not so much in Europe. Carbide layers on constructive parts and tools formed by a diffusion process, especially a vanadium carbide layer, have excellent tribological properties and some technical and economical advantages in comparison with carbide layers formed by chemical vapour deposition (CVD) and physical vapour deposition (PVD) processes. Diffusion formed layers are thicker with very strong bond to steel substrate and are produced using significantly cheaper equipment than for deposition coating. The process has one disadvantage: partial decarburization of the steel surface beneath the carbide layer reducing hardness and loading capacity of the surface. This disadvantage is eliminated by a developed and patented duplex process introducing previous carburizing to prevent decarburization and to form a hardened case under layer beneath the carbide layer. The new developed process should contribute to widely application of diffusion carbide coating for automotive industry. Mathematical model and program for optimization of process is presented as well as some examples of application: extruders for medium with very abrasive particles, aluminium die casting moulds, etc.

abrasive wear; adhesive wear; carbide layer; cold-work tool steels; diffusion; duplex process; digh-speed steels; hot-work tool steels; thermoreactive deposition; tribochemical wear; vanadising; vanadium carbide

S.I.e: Heat Treatment and Surface Engineering of Tools Dies. Rad je kao pozvano predavanje prezentiran na skupu 2th International congerence on heat treatment and surface engineering of tools and dies, održanom od 25.-28.05.2008.g., Bled, Slovenija ; prosireni sazetak objavljen u Knjizi sažetaka ; Vojteh Leskovšek (ur.) ; Ljubljana : Slovenian society for heat treatment, 2008. ; str. 81-83.