Structure and mechanical properties of electrodeposited Ni-AlN/Si3N4 composite coating

N1-AIN/Si3N4 composite coatings were successfully deposited on tungsten carbide by electrodeposition process. The influence of Si3N4 powder concentration on the microstructure, crystal structure and mechanical properties was investigated by using Scanning Electron Microscopy, Energy Dispersive Spectroscopy, X-Ray Diffraction and Vickers hardness tester, respectively. The results revealed that variation of Si3N4 concentration influenced the structure and mechanical properties of Ni-AlN/Si3N4 composite coatings. The fine surface morphology of composite was due to the inclusion of AlN and Si3N4 particles while it is rougher as the Si3N4 concentration was increased due to agglomeration effect and Ni crystal growth. The increase of microhardness is related to the particles dispersion- strengthening.