Properties of amorphous SiC coatings deposited on WC-Co substrates

Abstract

In this work, silicon carbide films were deposited onto tungsten carbide from a sintered SiC target on a r.f. magnetron sputtering system. Based on previous results about the influence of r.f. power and argon pressure upon the properties of films deposited on silicon substrates, suitable conditions were chosen to produce high quality films on WC-Co pieces. Deposition parameters were chosen in order to obtain high deposition rates (about 30 nm/min at 400 W rf power) and acceptable residual stresses (1.5 GPa). Argon pressure affects the energy of particles so that films with higher hardness (30 GPa) were obtained at low pressures (0.05 Pa). Wear rates of the coated pieces against a chromium steel ball in a diamond suspension medium were found to be about half of the uncoated ones. Hardness and wear resistance measurements were done also in thermally annealed (200-800 °C) samples revealing the effectiveness of SiC coatings to protect tool material against severe mechanical degradation resulting of high temperature (above 500 °C) oxidation

Low-Stress CMOS-Compatible Silicon Carbide Surface-Micromachining Technology—Part I: Process Development and Characterization

“…This amounts to a deposition time of 27 min for a 2-μm-thick film. This deposition rate is higher than those reported previously for RF sputtered SiC (18-30 nm/min) [25], [36], [37] and dc sputtered SiC (30 nm/min) [26].…”

“…a-SiC films can be deposited from an electrically insulating SiC target using RF magnetron sputtering, but previous reports indicate relatively low deposition rates of 18-30 nm/min at room temperature for these films [25], [36], [37]. Thus, none of the existing options satisfy all of the criteria necessary to implement a stress-controlled CMOScompatible deposition process.…”

LOW-TEMPERATURE (<300ºC) LOW-STRESS SILICON CARBIDE SURFACE MICROMACHINING FABRICATION TECHNOLOGY

“…A growth rate of 75 nm/minute was achieved at a deposition power of 2 kW. This is significantly higher than the 18-30 nm/min reported for a-SiC RF sputtering [17,18].…”

A New Two-Step Method for Laser Cladding of Silicon Carbide in Wc-Co Substrates

“…Another viable strategy is the deposition of intermediate layers, acting as diffusion barriers for Co and minimizing effects from the thermal expansion difference. Among several possible interlayers cited in the literature, silicon carbide (SiC) is pointed as one of the best options for such application 7,[10][11][12][13][14][15][16][17][18][19][20] . SiC is extensively used in abrasive tools, ceramics, insulation, metallurgical applications, refractories, and wear resistant materials, and this is due to its superior properties, including wide bandgap, low density, low thermal expansion, excellent thermal shock/oxidation/chemical resistance, high hardness, and high thermal conductivity 18,21 .…”