Electroless Deposition of Ni-P/nanoPTFE Composite Coating and Investigation of Its Properties

In this study, properties of Ni-P/nano PTFE coating deposited on aluminum substrate using commercial electroless nickel bath were studied.To carry out the research, micro hardness, thickness, roughness and morphological properties of the coating due to different PTFE solution densities and temperatures were studied. Effects of heat treatment on micro hardness and morphology of the obtained coating was investigated also. Vickers micro hardness and Rz and Ra parameters were measured for hardness and roughness, respectively.Particle distribution and chemical composition of the nanocomposite coatings were evaluated using SEM/EDS and XRD techniques. results showed that presence of nanoPTFE particles in the solution decreased the micro hardness ofNi-P from 520 HV to 250 HV and increased the roughness (Rz) from 1.49 to 4.6µm by changing the PTFE content from 2 to 14 g/l. Increasing the solution temperature from 75 to 90°C leaded to increase the hardness from 125 to 210 HV.Also it was found that heat treatment at 300°C for 4h increased the coatinghardness to 375 HV because of formationof Ni3P phases.