TY - JOUR
T1 - Friction and Damage Evolution of the Borided CoCrMo Alloy
AU - Morón, R. C.
AU - Rodríguez-Castro, G. A.
AU - García Maldonado, M. A.
AU - Salazar-Gaona, A.
AU - Bravo-Bárcenas, D.
AU - Campos-Silva, I.
AU - Palacios-Méndez, A.
N1 - Publisher Copyright:
Copyright © 2019 by ASME.
PY - 2019/8/1
Y1 - 2019/8/1
N2 - In this study, friction and evolution of cohesive failures (cracks and spallations) in CoB/Co2B layers were analyzed. Thermochemical treatment was carried out at 950, 975, and 1000 °C during 6, 8, and 10 h of exposure time, respectively. The characterization techniques include scanning electron microscopy (SEM) for morphology inspection of layers and thickness measurement, X-ray diffraction for the investigation of phases formed, and instrumented indention to obtain hardness, Young's modulus, and residual stresses. The practical adhesion of the boride layers was evaluated by a progressive load scratch test (PLST), and the critical loads of cracking, chipping, and spallation were calculated. Later, unidirectional multipass scratch tests (MPSTs) were performed by applying subcritical loads selected from the lower spallation load (54 N); these tests were conducted for a different number of scratch passes. The results show that the coefficient of friction (COF) and coating damage depend on the applied load, the number of passes, and coating thickness. In multipass scratch, the mechanical properties, residual stress state, and thickness play a significant role in the evolution of the coating damage that manifests in the form of cracks and cohesive spallations. Considering the scratch and multipass scratch results, it was found that the sample with 10 h of exposure time presents a better performance among the samples.
AB - In this study, friction and evolution of cohesive failures (cracks and spallations) in CoB/Co2B layers were analyzed. Thermochemical treatment was carried out at 950, 975, and 1000 °C during 6, 8, and 10 h of exposure time, respectively. The characterization techniques include scanning electron microscopy (SEM) for morphology inspection of layers and thickness measurement, X-ray diffraction for the investigation of phases formed, and instrumented indention to obtain hardness, Young's modulus, and residual stresses. The practical adhesion of the boride layers was evaluated by a progressive load scratch test (PLST), and the critical loads of cracking, chipping, and spallation were calculated. Later, unidirectional multipass scratch tests (MPSTs) were performed by applying subcritical loads selected from the lower spallation load (54 N); these tests were conducted for a different number of scratch passes. The results show that the coefficient of friction (COF) and coating damage depend on the applied load, the number of passes, and coating thickness. In multipass scratch, the mechanical properties, residual stress state, and thickness play a significant role in the evolution of the coating damage that manifests in the form of cracks and cohesive spallations. Considering the scratch and multipass scratch results, it was found that the sample with 10 h of exposure time presents a better performance among the samples.
KW - CoCrMo alloy
KW - adhesion
KW - boriding
KW - friction
KW - multipass scratch
KW - residual stresses
KW - scratch
UR - http://www.scopus.com/inward/record.url?scp=85067205117&partnerID=8YFLogxK
U2 - 10.1115/1.4043851
DO - 10.1115/1.4043851
M3 - Artículo
AN - SCOPUS:85067205117
SN - 0742-4787
VL - 141
JO - Journal of Tribology
JF - Journal of Tribology
IS - 8
M1 - 081602
ER -