Nanomechanical properties of induction cladded in-situ TiC reinforced titanium matrix composite coatings

Abstract

In order to reveal the correspondence between the microstructure and mechanical properties of in-situ TiC/Ti composite coatings by induction fusion coating, the nano-mechanical property variation patterns of different phase structures within the coatings were investigated by using the isolated nanoindentation test method, and the mechanical properties of the coating micro-zone structure were studied by using grid indentation test method. The isolated indentation results show that the nanoindentation hardness and elastic modulus of the in-situ TiC-reinforced phases are 21.3 GPa and 275 GPa, respectively, while the average nano hardness of the matrix phase in the α-Ti-rich and β-Ti-rich regions is 4 GPa and 6 GPa, respectively, and the average elastic modulus is 130 GPa and 155 GPa, respectively. The correspondence between the grid indentation and isolated indentation test results is good. The minimum peak obtained from the three-peak Gaussian fitting of the fractional nanoindentation test results represents the mechanical properties of the matrix phase of the coating, the middle peak reflects the comprehensive mechanical properties of the coating, and the maximum peak is lower than the real mechanical properties of the in-situ TiC reinforcement due to the influence of the reinforcement size and indentation position. Under the consideration of coating microstructure and reinforcement size, by reasonably setting the fractional indentation test conditions and selecting the appropriate test area, it can reveal comprehensive properties of the coating while obtaining real mechanical properties of different phase structures of in-situ TiC composite coatings.

Keywords

• induction cladding
• in-situ synthesis
• titanium-based composite coating
• nanoindentation