Fabrication and Properties of Plasma-Sprayed Al2O3/ZrO2 Composite Coatings

Autores: Dejang, N.|Limpichaipanit, A.|Watcharapasorn, A.|Wirojanupatump, S.|Niranatlumpong, P.|Jiansirisomboon, S.
Fuente: J.Therm. Spray Technol.
20(6), 1259-1268
2011

Al2O3 /xZrO2 (where x = 0, 3, 13, and 20 wt.%) composite coatings were deposited onto mild steel substrates by atmospheric plasma spraying of mixed a-Al2O3 and nano-sized monoclinic-ZrO2 powders. Microstructural investigation showed that the coatings comprised well-separated Al2O3 and ZrO2 lamellae, pores, and partially molten particles. The coating comprised mainly of metastable -Al2O3 and tetragonal-ZrO2 with trace of original a-Al2O3 and monoclinic-ZrO2 phases. The effect of ZrO2 addition on the properties of coatings were investigated in terms of microhardness, fracture toughness, and wear behavior. It was found that ZrO2 improved the fracture toughness, reduced friction coefficient, and wear rate of the coatings.