A new method for RB SiC (Reaction Bonded Silicon Carbide) surface modification is reported in this paper. Silicon is evaporated by E-gun

End-Hall ion source is imposed to ionize methane gas as a reactive gas

and it also assists coating formation to improve optical and mechanical quality

SiC:H coatings for modification are fabricated on RB SiC substrate. XRD (X-ray Diffraction) result shows all prepared coatings under the same condition areαphase. Hardness and elastic modulus are in the range of 9.781 GPa-13.087 GPa and 89.344 GPa-123.413 GPa

respectively. After surface-modification polishing and coating silver

reflectance is close to fine polished Zerodur glass coating with silver. Adhesion tests indicate the fabricated coatings adhere to the substrate firmly. Temperature impact experiments are performed through liquid nitrogen and boiling water for 5 cycles

no fall-off and cracks are observed.