Comparative Study on Microstructure and Properties of Electroless Ni-P and Ni-Cu-P Coatings Deposited on PEEK

Abstract

In order to better understand the advantages and disadvantages of Ni-P and Ni-Cu-P coatings, Ni-P and Ni-Cu-P coatings were deposited on surface of polyether ether ketone (PEEK) by electroless plating. Deposition rates of electroless Ni-P coating and Ni-Cu-P coating under different processes were compared. Surface morphology, composition and structure of the coatings were investigated through scanning electron microscope (SEM), energy-dispersive spectrometer (EDS) and X-ray diffractometer (XRD). Microhardness tester, surface roughness tester and MM-200 wear testing machine were used to evaluate the hardness, surface roughness and wear resistance of the coatings. The electrochemical performance and electromagnetic shielding performance of coatings were compared and studied through electrochemical performance and electromagnetic shielding performance tests. Results showed that electroless Ni-Cu-P coating had higher deposition rate. Ni-Cu-P coating was of a dense mixed crystal cauliflower-like structure, with higher hardness, better wear resistance in the later stage of wear, and better electromagnetic shielding performance. Whereas, the Ni-P coating was of a dense amorphous nodular structure with a smoother surface, better wear resistance in the early stage of wear, and better electrochemical performance.

Keywords

• electroless plating|wear resistance|electrochemical performance|electromagnetic shielding performance