Dry sliding behaviour of composite friction materials with varying iron and copper content prepared using the spark plasma sintering technique

ABSTRACT

Composite friction materials, with increasing Fe and decreasing Cu content, were produced using the spark plasma sintering technique. The samples were observed to contain a C-layer deposition on their surfaces, which was due to the C transfer from the graphite die. They were subjected to dry sliding tests on a pin-on-disc testing equipment. The friction and wear behaviour were found to be mainly influenced by the characteristics of the surface C-layer. In the specimens containing high Fe content, the surface C-layer was easily shed during sliding, resulting in elevated coefficient of friction and worn sample surfaces covered with smooth, compact, and continuous friction layer. Conversely, for samples containing low Fe and high Cu content, the C-layer was not completely removed during sliding, leading to low CoF and very mild pin wear. The sliding properties of low Fe content samples were improved with a pre-treatment, wherein the C-layer was mechanically removed.

KEYWORDS:

• Spark plasma sintering
• graphite
• pin on disc
• friction and wear
• iron
• copper

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

Priyadarshini Jayashree

Priyadarshini Jayashree. She received her M.S. degree in mechanical engineering from SUNY Buffalo, USA. She obtained her Ph.D. degree in 2021 in materials, mechatronics, and systems Engineering at the University of Trento, Italy. Her Ph.D. project focused on the development, testing, and characterization of new combinations of materials for high intensity braking applications. Following a Ph.D. period, she is currently working as a research fellow at the University of Trento, Italy.

Cinzia Menapace

Cinzia Menapace. She graduated in materials engineering from the University of Trento in 1999. She received her Ph.D. degree in metallurgical engineering from the University of Padova, Italy, in 2003. She has been working as a junior and senior researcher at the University of Trento for 20 years. Her current position is as a research assistant in metallurgy at the University of Trento, Italy. Her research interests include powder metallurgy, friction materials, and hot workability of metals.

Simone Turani

Simone Turani. He received his degree in materials engineering in 2001 at Politecnico of Milan. Since 2002 he joined Brembo initially as race engineer (2002-2005), then as testing engineer (2005-2012) and finally moved to R&D area as materials engineer (2012 till now), always in Racing Dept.. Actually he is involved in failure analysis (on returned parts from track), quality issues (on production process problems) and R&D activity (on materials for racing application).

Giovanni Straffelini

Giovanni Straffelini. He received his M.S. degree in materials science and engineering from the University of Trento, Italy, in 1989, and his Ph.D. in metallurgical engineering from the University of Padova, in 1993. He is currently a full professor in metallurgy at the University of Trento. His research interests include the mechanical properties of sintered alloys and weldments, the tribological behavior of materials, including friction materials for automotive and aerospace brakes, and the properties of surface engineered surfaces.