Enhanced Growth Rate of Chemical Vapor Deposition Diamond Coating Motivated by Graphene Oxide

Fan Zhou,Naichao Chen,Fasong Ju

doi:10.3390/coatings11050559

Abstract

To improve the growth rate of chemical vapor deposition (CVD) diamond coating, increasing the chemical reaction rate is essential. A novel method of dispersing graphene oxide (GO) particles as adsorbent on the substrate prior to deposition was proposed, with which the diamond coating with large grain size and high thickness was deposited on the silicon nitride under the normal CVD environment. The as-deposited diamond coating was characterized by scanning electron microscopy (SEM), surface profilometer, atomic force microscope (AFM), Raman spectrum, and indentation. The surface morphologies showed that the GO particles were covered by a layer of diamond coating. The diamond coating without and with GO particles had growth rates of 1.10–1.38 and 1.50–2.94 μm h−1, respectively. No differences in the Raman spectra of the microcrystalline diamond (MCD) coatings without and with GO particles were found. Indentation tests suggested that GO particles could enhance the adhesive strength and the crack resistance of diamond coating, which may result from the large thickness and the strong adsorbed capacity of destructive energy. Hence, dispersing particles on the substrate can be regarded as a potential and alternative technique by accelerating the CVD chemical reaction to obtain desired diamond coating.

Highlights

Chemical vapor deposition (CVD) diamond coatings have attracted intensive interest from scholars and engineers due to their remarkable properties, such as high hardness, great wear resistance and high thermal conductivity [1,2,3]
Prior to distributing the graphene oxide (GO) particles, all the substrates were submitted to a three-step pretreatment: (i) polishing by abrasive paper combining with diamond particles slurry for 20 min to roughen the surface; (ii) rinsing with deionized water in the ultrasonic vessel for 10 min; (iii) immersing into high-purity acetone ultrasonically cleaned for 20 min to remove the native impurities on the surface
GO particles undergone the heating treatment to verify whether they would decompose themselves at the temperate of 800–900 ◦ C for 4 h in the CVD deposition process or not

Summary

Introduction

Chemical vapor deposition (CVD) diamond coatings have attracted intensive interest from scholars and engineers due to their remarkable properties, such as high hardness, great wear resistance and high thermal conductivity [1,2,3]. Numerous experimental and theoretical studies were conducted to improve the properties of CVD diamond coating [4,5]. The surface area of substrate is closely associated with the total number of adsorbed hydrocarbon functional groups that considerably influences the chemical growth rate of diamond coating. In this way, rough pretreatments for substrate becomes a convenient and effective approach to accelerate the diamond nucleation [11]

Methods

Results

Conclusion