Influence of alloy composition on the tribomechanical properties of 50% blend of CoCrWMoCFeNiSiMn (stellite 1) and CoCrMoCFeNiSiMn (stellite 21) alloys.

Ahmed, R.; Kumar, V.; Faisal, N.H.; Marri, M.; Davies, S.

Abstract

This paper aims to investigate the structure-property relationship of the blend of two different carbide-type wear resistance Stellite® alloys, i.e. high carbon and tungsten CoCrW (Stellite 1) alloy and high molybdenum CoCrMo (Stellite 21) alloy. Blended alloys can be tailored to specific tribo-mechanical properties that cannot be achieved using standard pre-alloyed powders. Gas atomised powders were HIPed (hot isostatically pressed) in an argon environment for 4 hours at a temperature and pressure of 1200 ◦C and 100 MPa, respectively. The microstructure of the alloys was investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). Micro-hardness, macro-hardness (HV), tensile and Charpy impact tests were performed to characterise the mechanical properties. Wear properties were investigated using dry sand rubber wheel (DSRW), self-mated pin-on-disc (PoD) and ball-on-flat (BoF) tests. Relationships between the chemical composition of the alloys and total carbide fraction (TCF), hardness, yield strength, and Charpy impact energy (E_c) were investigated. Structure-property relationships are developed between the wear rate and chemical composition via mechanical properties. Wear mechanisms are discussed based on phase composition and alloy microstructure. The wear performance was more dominated by relationship ((TCF ×HV)/E_c ). Mathematical relationships of wear rate are developed which can be applied to both CoCrW and CoCrWMo alloy blends.

• Journal Article Type: Article
• Acceptance Date: Dec 17, 2024
• Online Publication Date: Mar 24, 2025
• Deposit Date: Mar 25, 2025
• Publicly Available Date: Mar 25, 2025
• Journal: Journal of materials engineering and performance
• Print ISSN: 1059-9495
• Electronic ISSN: 1544-1024
• Publisher: Springer
• Peer Reviewed: Peer Reviewed
• DOI: https://doi.org/10.1007/s11665-025-11034-7
• Keywords: Blending; Cobalt alloys; HIPing; Mechanical properties; Sliding wear; Stellite alloys; Structure–property relationship
• Public URL: https://rgu-repository.worktribe.com/output/2761274