Fierce competition demands more and more consideration for raw materials that are price competitive without the sacrifice of technical results. High and very often fluctuating raw material costs and availability challenge and complicate the calculation for brake pads raw materials. Therefore there is a strong demand for raw materials with high technical performance at stable predictable costs. For these reasons micaceous Iron Oxide (MIO) is evaluated. A case study describes the substitution of two well-established materials Zirconium Silicate and Potassium Titanate by micaceous iron oxide MIO in disk brake pads.
MIO is a naturally occurring mineral with lamellar particle shape. The study compares the addition of 3 wt-% and 6 wt-% of Zirconium Silicate, Potassium Titanate and of MIO in a low-metallic formulation for disk brake pads. Regarding technical performance several properties are evaluated. Tests for friction coefficients are carried out according to the AK-Master SAE J2522. The results show, that MIO provides higher friction coefficients than the compared products Zirconium Silicate and Potassium Titanate. Whereas, Zirconium Silicate and Potassium Titanate induce typical rates in thermal expansion, MIO leads to shrinkage of the brake pad combined with a slightly increased thermal transmission. The noise behavior was tested on a dynamometer according to SAE J2521. The noise index of MIO is higher than of Potassium Titanate and lower than of Zirconium Silicate. With MIO disks wear is slightly lower and brake pad wear is equal in comparison to the substituted materials. Moreover MIO provides comparable processing behavior and comparable physical characteristics (bulk volume, green strength, pad shearing strength, compressibility).
The case study shows that MIO substitutes Zirconium Silicate or Potassium Titanate with similar or better technical performance in the tested properties.