Brake Lining Materials and Their Characteristics
The friction materials of brake linings need to balance properties such as stable friction coefficient, good wear resistance, high temperature resistance, low noise, and low dust. Common material classifications are as follows:
Asbestos-based Materials
Widely used in the early days, asbestos fibers have strong heat resistance (withstanding 300-400℃), stable friction coefficients, and low costs. However, asbestos dust can cause lung diseases (such as asbestosis and lung cancer), so they have been banned in most countries. Currently, they are only rarely used in special scenarios (e.g., high-temperature heavy machinery).
Semi-Metallic Materials
Made with metal fibers (e.g., steel fibers, copper fibers) as the framework, mixed with resins and friction modifiers, they dominate the current market (accounting for over 70%).
Advantages: Good high-temperature stability (withstanding 600-800℃), strong wear resistance, and fast braking response, suitable for most family cars and commercial vehicles.
Disadvantages: High metal content (about 30%-60%) may accelerate brake disc wear, and noise is slightly higher at low temperatures.
Low-Metallic Materials
Reduce the proportion of metal fibers (usually below 20%) and increase organic fibers (e.g., aramid fibers) and mineral fibers to balance performance and comfort.
Advantages: More stable friction coefficient, low noise, and less wear on brake discs, suitable for models focusing on quietness and comfort (e.g., luxury cars).
Disadvantages: Slightly lower high-temperature resistance than semi-metallic materials and slightly higher cost.
Ceramic Materials
Mainly composed of ceramic fibers and inorganic fillers, mixed with a small amount of metal powder (e.g., copper powder), belonging to high-end friction materials.
Advantages: Excellent high-temperature resistance (withstanding 800-1000℃), stable friction coefficient, extremely low wear rate, almost no dust (dust is white and does not stain wheel hubs), and minimal noise, suitable for high-performance sports cars and high-end sedans.
Disadvantages: High cost (about 2-3 times that of semi-metallic materials), and slightly slow initial braking response at low temperatures.
Full Ceramic Materials
Completely free of metal, with ceramic fibers and ceramic particles as the core, mainly used in extreme scenarios such as racing cars.
Advantages: High temperature resistance (over 1000℃), lightweight, and extremely stable friction performance.
Disadvantages: Extremely high cost, low friction coefficient at low temperatures, and unsuitable for daily road use.
Organic Materials (NAO Materials, Non-Asbestos Organic Materials)
Based on organic fibers (e.g., resin fibers, cotton fibers), mixed with rubber and graphite.
Advantages: Extremely low noise, low dust, and almost no wear on brake discs, suitable for low-speed, light-load vehicles (e.g., electric vehicles, urban commuter vehicles).
Disadvantages: Poor high-temperature resistance (prone to failure above 300℃) and weak wear resistance, unsuitable for high-speed or heavy-load braking.
