Abstract: Diamond coatings were synthesized on the cemented carbide substrates of WC-6wt;Co pretreated by two-step and three-step pretreatments in CH3COCH3/H2 ambient adopt hot filament chemical vapor deposition.The WC-6wt;Co substrates pretreated were tested by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) to analyze the surface morphologies and cobalt content of WC-6wt;Co substrates.The optimum of three-step pretreatment was obtained thorough the comparison of pretreatment results between two-step and three-step pretreatment.surface morphology, crystalline property, adhesion between films and WC-6wt;Co substrates of diamond coatings were analyzed by SEM,X-ray diffraction (XRD) and hardness tester.

Key words: Diamond coatings were synthesized on the cemented carbide substrates of WC-6wt;Co pretreated by two-step and three-step pretreatments in CH3COCH3/H2 ambient adopt hot filament chemical vapor deposition.The WC-6wt;Co substrates pretreated were tested by scanning electron microscopy (SEM) and energy dispersive spectrometer (EDS) to analyze the surface morphologies and cobalt content of WC-6wt;Co substrates.The optimum of three-step pretreatment was obtained thorough the comparison of pretreatment results between two-step and three-step pretreatment.surface morphology, crystalline property, adhesion between films and WC-6wt;Co substrates of diamond coatings were analyzed by SEM,X-ray diffraction (XRD) and hardness tester.