KMT series

KMT (Potassium Magnesium Titanate) is an advanced, fiber-free ceramic compound designed to enhance the performance of friction materials, especially in NAO (Non-Asbestos Organic) and "Copper-Free" formulations. Its primary function is to act as a friction modifier and a contact plateau former. Its natural platelet morphology is key to its performance, as it:

• Stabilizes the coefficient of friction (µ).
• Significantly reduces wear at high temperatures.
• Improves NVH (Noise, Vibration, and Harshness) behavior.

Historically, fibrous titanates (known as "whiskers") were used. However, due to health concerns (potential to be respirable fibers), the industry has shifted to safer alternatives. RIMSA's KMT, with its platelet morphology, is inherently non-fibrous, complying with the strictest health and safety regulations without sacrificing tribological performance.

The platelet shape is fundamental for forming a stable contact surface on the brake pad. During braking, these platelets align parallel to the disc surface, helping to create secondary contact "plateaus." As demonstrated in tribological studies, these plateaus are crucial because they:

• Distribute load and pressure more uniformly across the surface.
• Create a more coherent and robust transfer layer (tribofilm), composed of the titanate itself, iron oxides from the disc, and other formula components.
• Reduce wear and particle emissions by promoting a smoother, more controlled wear mechanism.

The titanate's chemistry has a direct impact on performance:

• Coefficient of Friction (µ): Generally, potassium titanates (KT) tend to produce a slightly higher coefficient of friction.
• Wear Resistance: KMT (with magnesium) exhibits superior wear resistance, especially at high temperatures (e.g., 350°C). The magnesium helps to form larger and more stable secondary plateaus, which better protect the pad's matrix.

Therefore, KMT is the preferred choice for formulations where durability and low wear are the main objectives, while KT might be selected if maximizing the friction level is the goal.

Particle size is a key tool for the formulator, as it allows for tuning the titanate's mechanism of action:

• Fine Particles: They wear more easily and are actively integrated into the tribofilm (secondary plateaus). This promotes a very stable and uniform transfer layer, which generally leads to a higher and more stable coefficient of friction, albeit with slightly higher wear.
• Coarse Particles: They play a dual role. They function as primary plateaus (bearing the load directly) and, as they wear, their fragments contribute to the secondary plateaus. This dual mechanism typically results in a lower coefficient of friction and a lower wear rate, especially at high temperatures.

In summary: fine particles for higher friction, coarse particles for lower wear.