FE series

The FE series is a family of synthetic additives based on Iron (II) Sulfide (FeS). Its main function is to act as a high-performance solid lubricant and friction stabilizer at high temperatures. Like other metal sulfides, its mechanism of action involves:

• Modifying phenolic resin decomposition: It acts as a catalyst that controls the degradation of the resin at high temperatures, preventing a sharp drop in the coefficient of friction (fading).
• Forming a stable tribofilm: It contributes to the formation of a transfer layer (tribofilm) at the pad-disc interface, which stabilizes the coefficient of friction, reduces in-stop variability (stick-slip), and decreases wear.

Although both are iron sulfides, the differences in their origin, composition, and thermal stability are crucial:

• Purity and Consistency: FE10 is a high-purity synthetic product, manufactured under a controlled process. This guarantees consistent chemical composition and physical properties from batch to batch. Pyrite, being a natural mineral, contains variable impurities (SiO₂, PbO₂, etc.) that affect its performance.
• Thermal Stability: Pyrite (FeS₂) decomposes starting at 500°C, releasing sulfur dioxide gas (SO₂) which can cause "cavitation" or bubbles on the pad surface, destabilizing friction. FE10 (FeS) is thermally much more stable, with a melting point above 1100°C, ensuring reliable performance at the highest temperatures reached during braking.
• Hardness and Abrasiveness: Synthetic FeS is significantly softer (3.5 Mohs) than pyrite (6.5 Mohs). This makes it a much less abrasive material for the brake disc, contributing to reduced system wear.

FE50 is an advanced engineering version of iron sulfide, an innovative composite that further enhances performance:

• Controlled Oxidation Mechanism: FE50 is designed so that its oxidation mechanism at high temperatures differs from that of pure FeS. This tribochemical modification allows it to maintain its catalytic effect on the resin for longer, which translates into a significant reduction in wear at high temperatures (300°C and 500°C), as demonstrated by wear tests (SAE J2707).
• Fade Performance: Although its friction behavior is similar to other sulfides like Sb₂S₃ or SnS, the FE50 composite shows a remarkable improvement in wear reduction, outperforming even FE10 and other reference sulfides.

The FE series offers a fundamental strategic advantage: independence from LME (London Metal Exchange) prices. Unlike Antimony Trisulfide (Sb₂S₃) or Tin Sulfides (SnS, SnS₂), the price of iron is not subject to the same volatility. This makes the FE series an alternative with:

• A lower and more stable cost.
• A secure and predictable supply chain.

It allows formulators to develop high-performance pads without relying on metals with fluctuating prices.

The FE series is extremely versatile and is especially recommended in:

• "Copper-Free" (NAO) formulations: Where high-temperature stability is critical and a reliable solid lubricant is needed to replace the effects of copper and other metals.
• Heavy-Duty (HD) and Standard (PC/CV) applications: As a cost-effective alternative to pyrite, antimony, or tin, maintaining an excellent friction level and improving durability and wear.