Antimony trisulfide (Sb2S3) and tin sulfide (SnS) have long been essential components in brake pad formulations, contributing to friction stability, wear resistance, and noise reduction. However, the increasing prices of these metal sulfides, coupled with geopolitical uncertainties and supply chain challenges, are driving the brake industry to seek alternative materials. In this blog post, we will explore the factors motivating the search for replacements for Sb2S3 and SnS, discuss the challenges involved, and highlight Innovamat/RIMSA’s innovative solutions for navigating this evolving landscape.
The price problem
The prices of antimony and tin, the key metals in Sb2S3 and SnS, have been on an upward trajectory in recent years. The graph below illustrates the price trend of various metals, including antimony and tin, from 1995 to 2017.
As you can see, the prices of both antimony and tin have increased significantly, impacting the cost of brake pad production. In 2024, antimony prices skyrocketed due to Chinese export restrictions, further exacerbating the situation. The rising cost of raw materials creates economic pressure on brake pad manufacturers, prompting them to explore alternative materials that offer similar performance at a lower cost.
Geopolitical risks
Beyond price, the supply of antimony and tin is also subject to geopolitical risks. The production and export of these metals are concentrated in specific regions, some of which face political instability or potential trade conflicts. For instance, China dominates the production of antimony, while Indonesia is a major exporter of tin. Any disruptions in these regions could affect the availability and cost of these critical metals, impacting the brake industry.
The China factor
China’s dominance in the base metal market, including antimony, poses a significant challenge for the brake industry. Relying heavily on a single source for critical raw materials creates vulnerabilities in the supply chain. Diversifying the supply base by finding alternative materials can help mitigate these risks and reduce dependence on a single supplier.
The geopolitical risks associated with antimony and tin are further amplified by their importance in military and electronics applications.
- Antimony in military equipment: Antimony is a critical component in various military applications, including fire-retardant uniforms, bullets, and night vision goggles. Its strategic importance makes it susceptible to export controls and supply restrictions during times of geopolitical tension.
- Tin in electronics: Tin is essential for the production of electronics, particularly in solders used in circuit boards. The growing demand for electronics, driven by the rise of artificial intelligence, 5G networks, and electric vehicles, is putting further pressure on tin supplies.
The importance of Tribochemistry while exploring alternatives
Replacing traditional sulfides with alternative materials can alter the tribochemical reactions, potentially affecting the performance and longevity of the brake pad. Therefore, it is crucial to conduct thorough tribochemical analysis to ensure that any new material effectively replicates the desired tribological properties.
Finding suitable replacements for Sb2S3 and SnS requires a deep understanding of their tribochemical behavior. Tribochemistry is the study of chemical reactions that occur between surfaces in relative motion, such as those in a brake pad. The friction and wear properties of a brake pad are heavily influenced by the tribochemical reactions between the friction material and the counterface.
The search for alternatives to Sb2S3 and SnS is a complex endeavor. There is no one-size-fits-all solution, as the optimal replacement depends on the specific brake pad formulation and its intended application.
Innovamat/RIMSA’s solutions
Innovamat/RIMSA is at the forefront of developing innovative and sustainable solutions for the friction materials industry. We have a deep understanding of the challenges involved in replacing traditional sulfides, and we offer a range of solutions to meet the diverse needs of our customers, focusing on both running and future projects.
Synthetic Sulfides
Our synthetic sulfides are iron-based composites that offer enhanced performance compared to traditional synthetic sulfides. They can match the performance and wear of Sb2S3 in different applications, are cost-effective, antimony-free, and easily adaptable to different brake pad formulations. They are suitable for both aftermarket (AM) and original equipment (OE) applications.
FE50 – Provides increased performance and wear resistance at high temperatures when compared with conventional FeS. It is truly becoming a workhorse for many Sb and Sn replacement projects, with the best value for money on the market.
FZ10 – Offers excellent friction coefficient stabilization and wear reduction at medium and high temperatures. Intended to replace tin-containing sulfides in low-steel applications.
SF50 – Matches the performance and wear of SnS at high temperatures, even in demanding applications, with a reduced tin content.
Synergistic composites
Our synergistic composites are designed to match the performance and wear characteristics of Sb2S3 in various applications. These composites are cost-effective, antimony-free, and can be tailored to meet the specific needs of individual projects. They are particularly well-suited for aftermarket (AM) applications due to the flexibility in formulation.
Customer-centric approach
We understand that each customer has unique needs and priorities. Therefore, we work closely with our customers to understand their requirements and recommend the most suitable solution. Our team of experts can provide guidance on material selection, formulation optimization, and tribochemical analysis to ensure that our customers receive the best possible solution for their specific application.
In summary, the friction materials industry is facing a challenging landscape due to the increasing prices of legacy sulfides, geopolitical uncertainties, and supply chain complexities. However, these challenges also present opportunities for innovation and the development of sustainable solutions. Innovamat/RIMSA is committed to helping our customers navigate this evolving landscape by providing innovative materials, tailored solutions, and expert guidance. We believe that by working together, we can create a more sustainable and reliable future for the brake industry.
Contact us today to discuss your specific needs and explore how our innovative solutions can help you overcome the challenges of replacing traditional sulfides in your brake pad formulations.
