"Microestrutura e Propriedades Mecânicas de Recobrimentos Químicos de Ni-P"

摘要: The effect of heat treatment on the microstructure and mechanical properties electroless Ni-P coatings has attracted attention for various applications many which are in sectors petroleum gas, mining-metallurgy textile industry, where there is an increasing demand production better materials. These have been used mainly to prevent wear corrosion as alternative chromium, since its deposition processing very harmful health human environment. scarcity results literature concerning coating elasticity, toughness adhesion steel substrate motivated this study. with 8 10 wt%P thickness 13,5µm, were deposited ABNT 1020 heat-treated at temperatures between 300°C 650°C 1h. identification evolution phases a function temperature analyzed by X-rays diffraction. Analyses scanning electron microscopy (SEM) identified precipitates nickel fosfites, content increases temperature. Knoop Vickers indentation testing calculated hardness (H) elasticity modulus (E) coatings. showed that elastic reached maximum after 400 o C, 10,5 e 11,25GPa 187 191GPa modulus, Ni-8%P Ni-10%P respectively, while E/H reaches minimum 17 same treatment. Toughness increased treatment, being slightly higher lower P 2,2 1,9MPam ½ critical scratching load 50 58 N wt% respectively.