| Summary: | 碩士 === 國防大學理工學院 === 車輛及運輸工程碩士班 === 99 === This research purpose was to evaluate the tribological properties of electroless plating nickel based composite coatings by tribological tests and measurements. In this study, four different types of coatings such as Ni-P, Ni-P-SiC, Ni-P-Al2O3, and Ni-P-PTFE-SiC, Ni-P-PTFE-Al2O3, composite coatings were prepared by electroless plating techniques. Variable factors of the plating process include the concentration of surfactant and submicron ceramic particles. For this work, a reciprocating wear test machine was used to carry out these tribological experiments under dry lubrication and normal environment. The tribological mechanisms of Ni-P base composite coatings can be clearly examined by the measurements including coefficient of friction (COF), wear resistance, and surface morphology.
The results showed that the electroless Ni-P composite coating bath prepared by adding particulate, the result of particles in the coating with the dispersion strengthening phenomenon, and the supporting effect of the surface coating significantly improved the hardness, and after 400 ℃ heat treatment, the hardness of coating before heat treatment enhance about 50 ~ 80%, it caused by Ni3P precipitation strengthening. By dispersion strengthening of particles and precipitation hardening of Ni3P can effectively enhance the abrasion resistance of coating, and after adding PTFE can reduce the friction coefficient of coating, and has good wear resistance. The wear mechanisms of coating also shows the submicron particles by squeezing out of wear contribute to the formation of rolling friction to reduce friction and wear.
|
|---|
