Residual stresses and texture in Ni/SiC nanocomposite coatings

Abstract

Nanocomposites of Ni–SiC were electrodeposited on a 2024-T3 aluminum substrate in a nickel sulfamate bath. The goal of the study was to determine the effect of the SiC particle size and concentration on the crystallographic texture and residual stresses that develop in the nickel matrix. The presence of crystallographic texture, its nature, and its intensity affect all mechanical and physical properties of the coating. Residual stresses, if highly tensile, may be detrimental to the performance of the nanocomposite coating. The texture and residual stresses evolving in the coatings were studied using X-ray diffraction. Composites with nano-particles developed a strong 〈1 0 0〉 fiber texture and stresses that were compressive in small SiC concentrations, but tensile with low magnitude at greater concentrations. The composite with coarser SiC (500 nm) demonstrated a very weak 〈1 1 1〉 texture and residual stresses that are tensile in nature. Based on the findings, nanocomposites are expected to perform better than micro-composites that were electroplated using the same coating parameters.