Optimization of electroless bath process parameter for improving the tribology behavior of Ni-P/CaBr₂ composite coating against the hardened EN-31 steel

Abstract

Ceramic, polymers and solid lubricants were used as reinforcements in the electroless Ni-P deposit, which is in-soluble in nature. Impingement of in-soluble particles has improved the hardness and wear resistance of the Ni-P deposit. However, the question still remains on the bonding of matrix and reinforcement particle during the wear at high load conditions. Hence, to strengthen the Ni-P deposit, a soluble reinforcement particle (CaBr 2 ) has been used in this study. A detail study on the role of bath composition (Nickel sulphate and CaBr 2 ) on the mechanical and tribology behavior of alkaline electroless Ni-P/CaBr 2 composite coatings is reported. Coatings were carried out with various weight combination of CaBr 2 particle (1 g l −1 , 2 g l −1 , and 3 g l −1 ) and source of nickel (16 g l −1 , 18 g l −1 , and 20 g l −1 ) in the bath. The optimum bath composition to achieve higher hardness, low surface roughness (Ra), low coefficient of friction (COF), and wear rate were analyzed using response surface methodology (RSM). ANOVA was used to identify the influencing factor on the output responses and an empirical model has been formulated. Ni-P/CaBr 2 coating exhibited a high surface roughness of 1.505 μm for the weight combination of 1 g l −1 of CaBr 2 and 20 g l −1 of nickel sulphate. High surface hardness of 793 HV 0.05 and low wear rate of 3.33×10 −6 gm.m −1 was achieved for the high weight combination of CaBr 2 particle and nickel sulphate. The obtained experimental results were closer to the predicted results, confirming the significance of the model for optimizing the bath composition for Ni-P/CaBr 2 composite coatings. Various characterization techniques like Scanning Electron Microscope-Electron Dispersive Spectrum (SEM-EDS), x-ray Diffractometer (XRD) and 3D noncontact surface profilometer were used to justify the wear results obtained through the experimentation.

Investigation of the effect of surface modification types on the tribological performance of cow bone powder reinforced polymer materials

“…Accordingly, carbon, calcium, and silicon‐based compounds can be used as reinforcement elements 8,13–15 . The presence of these compounds improves the hardness and lubricity properties of the material as well as its strength 16 . It was reported in the literature that natural materials such as bone powder, mussel shells, and eggshells contain carbon, calcium, and/or silicon 13,17–19 .…”

“…8,[13][14][15] The presence of these compounds improves the hardness and lubricity properties of the material as well as its strength. 16 It was reported in the literature that natural materials such as bone powder, mussel shells, and eggshells contain carbon, calcium, and/or silicon. 13,[17][18][19] Sahin et al 20 investigated the mechanical and tribological properties of the material by reinforcing the polyphenylene sulfide (PPS) with mussel shell powder at different concentrations.…”