Sealing of plasma sprayed alumina by electrolysis, immersion and PVD coating deposition to obtain low friction

摘要: Thermal spraying is the name of a large group coating deposition techniques used to deposit thick layers for variety applications. The principle melt material, and rapidly propel droplets towards substrate where they flatten solidify. When properly used, not significantly heated. Spraying enables practically any material with stable molten phase, on solid material. Sprayed ceramics are reduce wear by sliding hard particles. However, due defect-filled microstructure resulting from spraying, coatings typically have poor mechanical tribological properties compared dense, sintered materials. By varying parameters, was influenced, also rate cohesion, which difficult quantify. Improved resulted axial particle injection equipment using narrowly size distributed, spherically shaped powder particles, conventional A new method seal open pores sprayed ceramic electrolysis proposed evaluated. It found that almost complete sealing could be obtained, in some cases giving drastically improved behaviour. studied electrolytically deposited sealants were Pb, Sn, Cu Ni. latter give best performance. proved possible apply PVD ceramics, it shown Ni-sealed alumina can superior ball bearing steel support thin, low friction coatings.