Diamond Deposition on Iron and Steel Substrates: A Review

Abstract

This article presents an overview of the research in chemical vapor deposition (CVD) diamond films on steel substrates. Since the steels are the most commonly used and cost-effective structural materials in modern industry, CVD coating diamond films on steel substrates are extremely important, combining the unique surface properties of diamond with the superior toughness and strength of the core steel substrates, and will open up many new applications in the industry. However, CVD diamond deposition on steel substrates continues to be a persistent problem. We go through the most relevant results of the last two and a half decades, including recent advances in our group. This review discusses the essential reason of the thick catalytic graphite interlayer formed on steel substrates before diamond deposition. The high carbon diffusion in iron would induce severe internal carburization, and then voluminous graphite precipitated from the substrate. In order to hinder the catalytic graphite formation, various methods have been applied for the adherent diamond film deposition, such as pre-imposed various interlayers or multi-interlayers, special controls of the deposition process, the approaches of substrate alloying and so on. We found that adherent diamond films can be directly deposited on Al alloying steel substrates, and then the role of Al alloying element was examined. That is a thin dense amorphous alumina sublayer in situ formed on the alloying substrate, which played a critical role in preventing the formation of graphite phase and consequently enhancing diamond growth and adhesion. The mechanism of Al alloying suggests that the way used to improve hot corrosion resistance is also applicable. Then, some of the hot corrosion resistance methods, such as aluminizing, siliconizing, and so on, which have been used by some researchers examining CVD diamond films on steel substrates, are reviewed. Another way is to prepare diamond-like carbon (DLC) films on steel substrates at low temperature, and then the precipitated graphite from the internal carburization can be effectively avoided. In addition, based on some new findings, the understanding of the diamond nucleation and metastable growth is discussed.

Plasma Carburizing of Laser Powder Bed Fusion Manufactured 316 L Steel for Enhancing the Surface Hardness

“…A model for diamond nucleation by energetic species was proposed by Lifshitz et al [41]; it involves spontaneous bulk nucleation of diamond embryo clusters in an amorphous carbon hydrogenated matrix and ion bombardment-induced growth through a preferential displacement mechanism. The model has been confirmed by TEM observations of Li et al [45].…”

“…Gas mixtures (H 2 /CH 4 ) are commonly employed to grow synthetic polycrystalline diamond films and the addition of CO 2 is demonstrated to enhance the growth rate and crystalline quality of nano-diamond layers [38][39][40]. The reason why meta-stable diamond crystals can nucleate and grow on non-diamond substrates under CVD conditions is a problem that has been extensively debated (e.g., see [41][42][43][44][45]) since the most stable C phase is graphite and the phase transition has a high activation barrier (~0.4 eV/atom) that can be overcome under extreme conditions of temperature and pressure. A model for diamond nucleation by energetic species was proposed by Lifshitz et al [41]; it involves spontaneous bulk nucleation of diamond embryo clusters in an amorphous carbon hydrogenated matrix and ion bombardment-induced growth through a preferential displacement mechanism.…”

Tribochemical Interactions between Graphene and ZDDP in Friction Tests for Uncoated and W-DLC-Coated HS6-5-2C Steel

“…There was interaction between W and carbon from W-DLC with formation of WC carbides. Through this tungsten diffuse to the surface [33].…”

Combinatorial Materials Design Approach to Investigate Adhesion Layer Chemistry for Optimal Interfacial Adhesion Strength

“…This makes NCD coatings suitable for many applications and attractive to numerous industries [25,26]. However, depending on the type of substrate, they also exhibit a weak interface bonding strength, requiring the application of adhesion promoting interlayers [27][28][29]. Therefore, a unique shutter system allowing for precise control over coating design has been integrated into a conventional physical vapor deposition (PVD) system to produce a matrix of single element and cosputtered binary metallic alloy compositions, based on established adhesion promoting elements (Ta, W, Cr) [24,[30][31][32][33][34] on single Si wafers.…”