Influence of droplet-free ta-C coatings and lubrication conditions on tribological performance and mechanical characteristics of WC−Co

• DOI: 10.1016/j.matlet.2024.137058
• Publication Date: 2024-07-22T23:11:30Z
• Authors: Koki Murasawa; Mohamed Ragab Diab; Mei Wang; Hiroshi Naragino; Tsuyoshi Yoshitake; Mohamed Egiza
• Keywords: Wear resistance; Tribological performance; Arc ion plating; Ta-C coatings; WC−Co substrates

Cemented carbide (WC−Co) tools suffer from surface abrasion, limiting their performance. This study explores droplet-free tetrahedral amorphous carbon (ta-C) coatings deposited via arc ion plating as a solution. The coatings possess a dense, sp3-rich structure, leading to a remarkable hardness of 60 GPa compared to 37 GPa of WC−Co, and strong adhesion with a critical scratch load of 41 N. Tribological tests confirm their effectiveness. Dry sliding tests show reduced wear and lower CoF (0.123) compared to uncoated tools (0.159). Notably, water-soluble lubricants yielded the best performance (lowest CoF: 0.092, superior wear resistance), while water and mineral oil also improved performance.