Microstructure Of Ni-based Alloy Research Articles

Characterization and Tribological Behavior of Ni-Base Alloy Coatings Prepared by Electro-Spark Deposition

Ni-base alloy coatings on carbon steel surface were prepared by electro-spark deposition technology and the characterization and tribological behavior of the coatings were investigated. The research results show that the microstructure of Ni-base alloy coating can be divided into three typical areas: the white alloy zone, transition zone and overheating-affected zone. The hardness across the interface of the coating and substrate, in which chemical elements transferred from the coating to substrate, gradually decreases with the depth away from the coating surface. The friction coefficient slightly decreases, while the wear loss increases with the increase of load. The main wear mechanism of the coating is micro-cutting wear at light load friction, and gradually changes into mixture of micro-cutting wear, multi-plastic deformation wear and adhesive wear at heavy load friction.

Effect of Y 2O 3 addition on microstructure of Ni-based alloy + Y 2O 3/substrate laser clad

To improve hardness and corrosion resistance of aluminum substrate, using laser cladding technique, metal composite with Ni-based alloy, refining and dispersion strengthening Y 2O 3, particle hardening W, Cr was obtained. The microstructure and morphology, phase identification, element diffusion and composition analysis of the Ni-based alloy + Y 2O 3/substrate laser clad and laser clad/aluminum substrate interface were examined using scanning electron microscopy (SEM), Electron Probe Microanalyzer (EPMA), energy-dispersive spectrometer (EDS) analysis. The corrosion resistance was investigated also. The results showed, with the addition of Y 2O 3, more fine microstructures consisted of isometric crystal, white acicular crystal and fringe crystal; primary phases were mainly Ni 3Al, NiAl, NiAl 3, W, α-Al and Cr x C. The corrosion rate of aluminum substrate was nearly two times more than that of laser clad metals with addition of Y 2O 3.