Effects of the Modification of Processing Parameters on Mechanical Properties of HVOF Cr2C3-25NiCr Coatings

Autor: Israel López Báez, Carlos Agustín Poblano Salas, Luís Gerardo Trápaga Martínez, Juan Muñoz Saldaña
Rok vydání: 2015
Předmět:
Zdroj: Journal of Thermal Spray Technology. 24:938-946
ISSN: 1544-1016
1059-9630
DOI: 10.1007/s11666-015-0255-x
Popis: The present work shows that some mechanical properties of Cr2C3-25NiCr coatings processed by HVOF thermal spraying such as elastic modulus, hardness, fracture toughness, and wear resistance are closely linked to selected processing parameters as well as to chemistry, structure, and morphology of the feedstock material. Optimization of processing parameters was based on oxygen concentration measurements inside the flame, studied by a contour plot, and curvature data recorded during spraying. The increase in velocity of in-flight particles strongly affected the interfacial fracture toughness of the coatings, as a maximum K IC of 3.71 MPa m1/2 was reached when particle velocity increased to ~765 m/s. The micro-hardness of Cr2C3-25NiCr coatings was widely varied by changing the HVOF spray conditions, i.e., the amount of reinforcing phases and inter-splat adhesion were quite sensitive to any modification of the processing parameters. It was also found that coatings having a high inter-splat adhesion and/or low degradation of reinforcing hard phases showed reduced weight loss during erosive wear tests. Finally, from the experimental evidence reported in this work, a correlation between the elastic bending modulus of coatings and indentation crack length was also found.
Databáze: OpenAIRE