LAUSR

Abstract Highly oriented β-SiC bulks with high hardness were fabricated by halide laser chemical vapor deposition (HLCVD) using SiCl 4 , CH 4 and H 2 as precursors. The effects of total pressure ( P tot ) and deposition temperature ( T dep ) on the preferred orientation, microstructure, deposition rate ( R dep ) and micro-hardness were investigated. The 〈110〉-oriented β-SiC bulks were obtained at low P tot (2–4 kPa), non-oriented β-SiC bulks were obtained at mediate P tot (6 kPa), and 〈111〉-oriented β-SiC bulks were obtained at high P tot (10–40 kPa), exhibiting faceted, cauliflower-like and six-fold pyramid-like microstructure, respectively. The maximum R dep of 〈111〉- and 〈110〉-oriented β-SiC bulks were 3600 and 1300 μm/h at, respectively. The activation energy obtained by the plot of lg R dep - T dep −1 is 170 to 280 kJ mol −1 , showing an exponential relation with P Si . The Vickers micro-hardness of β-SiC bulks increased with increasing P tot and showed the highest value of 35 GPa at P tot  = 40 kPa with a complete 〈111〉 orientation.