Performance characterization and preparation of Ni-SiC nanocomposites based on SCF-CO 2.

Composite electrodeposition based on supercritical carbon dioxide fluid (SCF-CO2) was used in preparing Ni-SiC nanocomposites with high micro-hardness. The process parameters were optimized by orthogonal test. The effect of cathodic current density, supercritical fluids pressure, temperature and adding quantity of SiC particles to the micro-hardness and co-deposition rate of the nanocomposites were studied. The results show that the micro-hardness of Ni-SiC nanocomposites is as high as 929.3 HV with the work pressure 13 MPa, temperature 50°C, current density 7 A·dm−2and SiC particles adding amount 10 g·L−1, which is improved 78.57% than that of common composite electrodeposition. Then the surface morphology and energy spectrum of Ni-SiC nanocomposites were analyzed by scanning electron microscope (SEM). The results show that the SiC particles are much uniformly distributed in the nanocomposites and the SiC particles content in which reaches 2.84 (wt%) when working pressure is in 8∼16 MPa. These properties are significantly higher than those of common composite electrodeposition. [ABSTRACT FROM PUBLISHER]