Surface properties investigation of Ni-P-BN (h) coatings on 1050 aluminium substrate with nanostructured anodic oxide interlayer

摘要

The aim of this study is to investigate the hardness, wear and electrochemical behaviour of hexagonal boron nitride [BN (h)] particles reinforced electroless nickel coated 1050 aluminium alloy (AA1050). The alloy was initially anodized and an electroless nickel composite coatings (ENCC) with BN (h) was subsequently deposited. ENCC were obtained from a hypophosphite bath containing 1, 5 or 10 g/l of BN (h) particles. To prevent agglomeration of BN (h) particles in the plating bath, an anionic surfactant (sodium dodecyl sulphate) were used. Potentiodynamic polarization tests studies carried out in 3.5 wt.% NaCl solution. The highest hardness value was measured as 658 HV_(50) in the sample containing 10 g/l BN (h). The morphology and microstructure of the coatings were analysed using field emission scanning electron (FESEM) and confocal laser microscopies. The surface composition and phase structure analysis have done with the help of energy dispersive X-ray analysis (EDX) and X-ray diffraction analysis (XRD) respectively. The wear tests have conducted on a pin-on-disk tribometer at room temperature under dry conditions.