HVOF sprayed WC-CoCr coatings on aluminum: tensile and tribological properties

13th International Conference on Tribology

Koutsomichalis, A.^1 ; Vardavoulias, M.^2 ; Vaxevanidis, N.^3

Hellenic Air-Force Academy, Department of Aeronautical Studies, Dekelia Air Force Base, Attica

TGA 1010, Greece^1

Pyrogenesis S.A, Technological Park of Lavrio, Lavrio

GR 195 00, Greece^2

School of Pedagogical and Technological Education, Dept. of Mechanical Engineering Educators, Heraklion, Athens

GR 141 21, Greece^3

关键词: Aluminum substrate;    Coating-substrate interface;    Comprehensive assessment;    Friction coefficients;    Microstructural analysis;    Pin-on-disk method;    Sliding wear behaviour;    Tribological properties;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/174/1/012062/pdf
DOI  :  10.1088/1757-899X/174/1/012062

来源: IOP

【 摘 要 】

This paper provides a comprehensive assessment of the tensile and sliding wear behaviour of WC-10Co4Cr agglomerated and sintered powder deposited on aluminum by Hyper Velocity Oxy-Fuel (HVOF) process. Microstructural analysis (SEM) identified grains of tungsten carbide (WC) in the metal matrix of the cobalt-chromium (Co-Cr). A transformation of the WC in the W2C phase was observed and decomposition of WC in the metal matrix. The HVOF WC-Co-Cr coating was found to decrease tensile strength of the aluminum substrate. Transverse cracks were observed to initiate on the coating surface, increasing rapidly with the increase in tensile strain and stopped on the coating-substrate interface causing decohesion. Tribological properties were examined using the pin-on-disk method under various loads. The friction coefficient rose abruptly at the start-up phase and stabilized at almost the same sliding distance independently of the applied load. Both the friction coefficient and the wear volume were found to increase with increasing applied load. Study of the wear mechanisms revealed surface micro-cracking and fragmentation of flattened coating layers with subsequent gradual pull out of the carbide particles.