Differences in Wear and Material Integrity of NAO and Low-Steel Brake Pads under Severe Conditions

Autor: Edouard A. T. Davin, Anne-Lise Cristol, Arnaud Beaurain, Philippe Dufrénoy, Neomy Zaquen
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Materials, Vol 14, Iss 19, p 5531 (2021)
Druh dokumentu: article
ISSN: 1996-1944
DOI: 10.3390/ma14195531
Popis: In this study, through severe reduced-scale braking tests, we investigate the wear and integrity of organic matrix brake pads against gray cast iron (GCI) discs. Two prototype pad materials are designed with the aim of representing a typical non-metal NAO and a low-steel (LS) formulation. The worn surfaces are observed with SEM. The toughness of the pad materials is tested at the raw state and after a heat treatment. During braking, the LS-GCI disc configuration produces heavy wear. The friction parts both keep their macroscopic integrity and wear appears to be homogeneous. The LS pad is mostly covered by a layer of solid oxidized steel. The NAO-GCI disc configuration wears dramatically and cannot reach the end of the test program. The NAO pad suffers many deep cracks. Compacted third body plateaus are scarce and the corresponding disc surface appears to be very heterogeneous. The pad materials both show similar strength at the raw state and similar weakening after heat treatment. However, the NAO material is much more brittle than the LS material in both states, which seems to favor the growth of cracks. The observations of crack faces suggest that long steel fibers in the LS material palliate the brittleness of the matrix, even after heat damage.
Databáze: Directory of Open Access Journals
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