The stabilization of coefficient of friction and reduction of the wear by sulfides are related to their contribution to modify the phenolic resin decomposition. Synthetic iron sulfide has been always seen as a low cost and stable in price alternative to other metal sulfides, but with some drawbacks in terms of high temperature behavior, due to its oxidation mechanism over 400ºC transforming into Iron Oxide and losing its catalytic effect. Previous works of Innovamat have shown how the microstructure of the sulfide can influence the tribochemistry, oxidation temperature range and oxidation products produced by a composite sulfide. This change in tribochemistry is responsible for the variation in the wear and friction behavior. This work explores in-situ reactivity (brake pad) of the two different synthetic iron sulfide based products, and correlates those data with previous reactivity data obtained outside of the pad. This work go deeper in understanding how adjusting the oxidation mechanism of synthetic iron sulfide leads to a modification of pad tribochemistry that contributes to the reduction of the brake pad wear, and so, improving the brake emissions, while also improving one of the historical problems of iron based sulfides, the powder agglomeration and low shelf-life. The iron sulfide composite allows similar friction performance but significantly reduces the wear of the brake pad, and therefore the emissions, due to the different oxidation mechanism in comparison to the pure iron sulfide. We will be sharing pad cross section elemental map distribution obtaind by SEM-EDS, that shows the reactivity of the sulfides prior to reach the pad surface after SAE standard tests by using brake pad screening tribometer, and XRD, TG-DTA and IR data for reactivity characterization. With this work it is expected to contribute to better understanding of sulfides behavior in friction material, allowing the community to find new ways to be more sustainable, going LME independent in their current and future challenges, especially those related to emissions control, electrification and friction material commoditization.
Dr. Carlos Lorenzana, Chief Innovation Officer, RIMSA METAL TECHNOLOGY, SA; Dr. Andrea Sliepcevich, R&D Manager, Quartz Srl; Dr. Michael Conforti, R&D Manager, Quartz Srl; Ing. Diego Chávez, R&D Senior Researcher, RIMSA Metal Technology SA