Friction pads

Parts of a machine, which divert or transmit the Mechanical Force owing to their frictional behavior, are called: “Friction Pads”. Brake shoes and Clutch Disks are examples. Manufacturers have tried various materials to produce such parts. 
As for the history; enough to say that somebody named Herbert produced the first friction pad in 1897, made of Cotton based textile impregnated in Bitumen. The textile was replaced with a mineral based substance named “Asbestos” in 1920. Asbestos, then, became the most common ingredient of Friction Pads. However, Asbestos abandoned and replaced later, due to environmental hazards.

Essential Characteristics of Friction Pads’ material:

1. Friction coefficient: Since the performance is based on Friction Behavior, a high Friction Coefficient is required. This scalar parameter is a value without unit, measured by a device named “Chase”.
2. Abrasion rate: Substances should have a high resistance against scratch, Erosion, abrasion, Pitting corrosion, and Thermal erosion.
3. Heat Conductivity: Converting the kinetic energy into thermal, high Heat Conductivity and Thermal Capacity is essential; so that the generated heat can be transmitted to the environment, preventing consequent damages to adjacent parts.
4. Friction stability: Friction stability preserves the friction coefficient in high temperatures, humidity and various speeds.
5. Noise and vibration: It is always an issue to eliminate or minimize the noise and vibration. Therefore solutions such as chemical synthetics and silencers are utilized.
6. Corrosion resistance: Working in corrosive and humid conditions, corrosion resistance is a crucial criterion of components.
7. Bio-Environmental aspects: This parameter was included in designing criteria in recent decades, why for “Asbestos” was disqualified in manufacture process due to serious and numerous hazards for Bio-environment, despite effective performance.

Main Ingredients of Friction Pads:
1. Abrasive Material
2. Friction productive & corrective material
3. Fillers and Re-inforcers
4. Joining material

Friction Pad types in terms of ingredients and Fabricate process:
1.Friction pads sintered method powder metallurgy
2- Mechanical abrasion-resistant steel plates
3- Brass synchronizer rings