Indentation damage to boron carbide–DLC coatings with different compositions

• Published in: Surface & coatings technology 2004-05, Vol.183 (1), p.1-9
• Main Authors: Nekkanty, Srikant, Walter, Mark E.
• Format: Article
• Language: English
• Subjects: Boron carbide–DLC; Composite hardness; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Mechanical and acoustical properties; Physical properties of thin films, nonelectronic; Physics; Scanning electron microscopy; Sputtering; Surfaces and interfaces; thin films and whiskers (structure and nonelectronic properties); Vickers hardness test
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/S0257-8972(03)00878-8

Recently, a reactive sputtering process involving boron carbide (BC) targets and hydrocarbon gases has been used to produce novel, nano-composite thin films comprised of nano-sized amorphous BC regions embedded in a matrix of hydrogenated amorphous carbon (Diamond-like carbon, DLC). This paper discusses the results of Vickers indentation experiments carried out on four different BC–DLC composition coatings that were sputtered deposited onto 52 100 steel disks. The indentation depths ranged from less than 10% of the coating thickness to many times more than the coating thickness. In all cases, different coating compositions resulted in different indentation depths. Composite hardness curves have been generated for the different coatings. The indentations and the associated crack patterns were observed using scanning electron microscopy, and coating crack lengths were quantified.