A competitive-adsorption chemical vapor deposition method: Diamond coated on WC-Co substrate without acid-alkali pretreatment by adding graphene oxide particles

Abstract

Detrimental components existed in substrate surface are regarded as a severe barrier of growing the chemical vapor deposition (CVD) coating. In this work, a novel competitive-adsorption CVD method was proposed to deposit the diamond coating on Co-cemented tungsten carbide (WC–Co) substrate without traditional acid-alkali pretreatment. Graphene oxide (GO) particles were adopted as the adsorbent to introduce the competitive adsorption with Co element during deposition. Four different GO concentrations were conducted to evaluate the effect of GO particles on the coating. The results shown that the WC-Co substrate with GO particles and without pretreatment can be covered by the integrated microcrystalline diamond (MCD) coating (GO-MCD) that presented the similar surface morphology to the MCD coated on WC-Co substrate with acid-alkali pretreatment (P-MCD). Furthermore, Raman spectra, AFM, XPS and XRD patterns only presented a slight difference between the GO-MCD coating and the P-MCD coating. Indentation test suggested that GO particles can enhance the adhesion strength and crack resistance of diamond coating. Meanwhile, GO particles did not deteriorate the tribological property of diamond coating. Hence, our proposed method might provide a promising approach to deposit the desired coating on the given substrate even with some detrimental components.