Boron-Carbon Coatings: Structure, Morphology, and Mechanical Properties

Abstract

Boron-doped carbon coatings have been produced by a method combining the deposition of a pulsed carbon plasma coating and a boron flow formed as a result of the evaporation of a boron target by pulsed YAG: Nd3+ laser irradiation. Phase, chemical composition, structure, and mechanical properties of composite boron-carbon coatings have been determined. Changes in the coatings’ roughness depending on the boron concentration have been established using atomic force microscopy. It has been shown that the grain size is on the rise with increasing boron concentration. Raman spectroscopy has revealed that at a boron concentration of 43.2 at. %. There is a sharp increase in the ID/IG ratio, which indicates the carbon component’s graphitization. Low ID/IG ratios are observed in the coating at low boron concentrations (no more than 17.4 at. %), suggesting a high content of carbon atoms with sp3 bond hybridization. The coating studies, carried out by X-ray photoelectron microscopy, showed that boron could be in a free state or in the form of carbide or oxide depending on the concentration in the coating. In this case, with an increase in boron concentration, there is a decrease in the concentration of carbon atoms in the state with sp3 bond hybridization, accompanied by an increase in the number of B-C bonds and a reduction in the boron concentration not associated with carbon and oxygen. These coating and chemical composition features determine the boron concentration’s established non-monotonic nature on their microhardness, elastic and mechanical properties. Keywords: composite carbon coatings, boron-doped, atomic force microscopy, X-ray photoelectron microscopy, Raman spectroscopy, microhardness, scratch.

Impact of Magnetic-Pulse and Chemical-Thermal Treatment on Alloyed Steels’ Surface Layer

“…During this time, the alloying elements' carbides and nitrides do not have time to grow to full sizes which inhibits further nitrogen diffusion into the metal. The presence of carbon and alloying elements [42] increases lattice defects and accelerates diffusion [43].…”

Surface Strengthening Technology for Hammers of a Four-Die Forging Device

“…Different brands of stamped steels are used to make radial forging machines. Steels used for heat-deforming dies must have high mechanical properties [21] (strength and toughness) at elevated temperatures and high scale resistance and heat resistance, i.e., the ability to withstand repeated heating and cooling without the appearance of hot cracks [22]. Steels must also have high wear resistance and thermal conductivity for industrial heat transfer transmitted by the workpiece [23][24][25].…”

Application of ANN for Analysis of Hole Accuracy and Drilling Temperature When Drilling CFRP/Ti Alloy Stacks

“…Various factors were reported to affect the hole quality parameters in CFRP/Ti alloy stacks, including drill bit wear rate [ 6 , 25 , 26 , 27 , 28 , 29 ], cutting tool coating [ 4 , 15 , 22 , 26 , 30 , 31 , 32 ], cutting parameters [ 10 , 11 , 14 , 33 , 34 ], drill bit geometry [ 8 , 21 , 35 , 36 ], dynamic characteristics of CFRP [ 37 ], drilling strategies, and techniques, namely one-shot drilling of the stack [ 10 , 11 , 14 , 22 , 33 , 35 , 38 , 39 , 40 , 41 ], stepped bit geometry drilling [ 8 , 21 ], pilot hole drilling [ 42 ], cryogenic drilling [ 43 , 44 ], minimal quantity lubrication (MQL) [ 29 , 45 ], helical milling [ 9 , 46 ], and drilling with core drill [ 47 ]. In such a way, it can be summarized that one-shot drilling of CFRP/Ti alloy stacks is still a mainstream technology of manufacturing holes studies; we concluded that the most promising factors to improve the hole quality are the cutting parameters of the one-shot drilling strategy.…”