Friction materials—also known as brake materials and clutch materials—are a type of material used to induce resistance in situations where slow or decreased movement is necessary. Applications include clutch and brake systems, operating systems, automotive equipment, and industrial machinery all need to be able to stop or slow down their processes. Components such as friction pads and linings and disc brake pads are made from friction materials.
In order to provide additional friction and thus increase their efficiency, friction materials are textured or have a rough surface. Manufacturers utilize smoother surfaces to transport materials more efficiently. However, the more texture is added to a surface, the greater the amount of energy required to move over it. In turn, an object can be more easily slowed down or stopped.
Since heat energy is a byproduct of the process of creating friction, materials that are resistant to heat are commonly used to make friction materials. The most popular choice for friction materials used to be fibers made from asbestos. However, due to the increase of health concerns associated with exposure to asbestos, ceramic has become a popular material to use as an alternative.
Ceramic is highly durable and resistant to heat, and is thus used in high-friction environments. Friction materials need to be capable of enduring high amounts of physical stress, since the wearing down of material unavoidably produces friction. Applications that require friction materials to properly function include brake blocks, brake shoes, friction discs, clutch discs, clutch discs, disc brake pads, clutch facing, brake lining, brake bands, clutch sets, and brake pads. Industries that make frequent use of these products include construction, automotive, forestry, oil and gas, and mining. Read More…
The definition of friction is the resistance to relative motion that opposes an object’s direction of movement. Friction is created when a solid object comes into contact with a diverging surface. Friction can be used anywhere from simply slowing down or stopping an object, or accelerating it to a certain speed. The type of material used depends greatly on the type of friction that is needed. Types of friction include static, kinetic, and rolling friction. The first, static friction, occurs when two solid objects do not move relative to each other, and movement is prevented altogether.
An important thing to consider when implementing this type of friction is the slope of the surface. Kinetic friction, or dynamic friction, happens when two objects move relative to one another. One surface may be moving along a stationary object, or both surfaces may be in motion. In the occurrence of rolling fiction, wheels or balls are utilized. A wheel or ball is caught by a rough material, preventing it from slipping or sliding. For example, when a car tire spins on ice or snow, friction prevents it from catching on the ground and allows it to keep rotating.
Two key requirements of every friction material are sufficient energy absorption, and a high coefficient of friction. In order to ensure maximum effectiveness, it is necessary to be familiar with the system for which the friction component will be used. A material with a high amount of friction is essential in situations where an object needs to be quickly stopped. Heat generation is another thing to consider.
The materials that were once ideal were carbon and resin-bonded asbestos. However, continued developments in technology have made a wider variety of materials available. For example, ceramic has become a popular material due to its heat-resistant properties. Products such as semi-metallic brake materials are made using brass, copper, and steel wool bonded by resin. These elements are similar to ceramic in terms of durability.
Friction materials are used in braking systems to slow down wheels or bring them to a stop, as well as preventing movement altogether for other components. Pressing a brake activates a system where a friction material is placed against a moving disc, thus slowing down the connecting wheels. Friction discs are commonly made from metal. However, the use of metal has a drawback, which is the grinding noise created when friction is applied. It is common for manufacturers to coat metallic braking components with other high friction materials such as rubber.
The addition of rubber enhances the braking system’s ability to produce surface friction. The different mechanisms that are activated during the braking process include brake pads, linings, blocks, and shoes. Clutch discs and clutch facing operate in a similar way so the clutch is engaged and disengaged efficiently. The production of fiction has become an industry all its own in addition to being a vital aspect of numerous other industries.
The constant evolution of the industry has influenced manufacturers to keep their friction material compositions and advancements a secret in order to set them apart from the competition. For example, the introduction of ceramic into the industry has opened numerous doors as to how efficient and durable friction materials can be made. Reduced noise and faster stoppage have become common demands for braking and clutch products. Technological developments are constant in this industry, and thus, the quality of frictional materials have come a long way and will continue to advance.
Friction Materials: Stopping Things from Running Away for Ages
Friction is a natural force resulting from two surfaces sliding over each other. We may not always like friction, but we need it. We use friction materials to create friction, which reduces or stops the motion of things that we want to stop. A simple example is a car—if we do not have the ability to control the movement of the vehicle, it would be useless to us, and friction materials, such as ceramic brake pads and brake shoes, help us to do that. This is when we understand why friction is such an important force for us.
Friction is everywhere; not a moment passes without encountering this force of nature. There are many types of friction–dry friction, fluid friction, lubricated friction, skin friction, and internal friction. When you slam the brake in your car, the brake lining of the brake system encounters the friction disc or the drum (in a drum brake set up), generating enormous force of friction that reduces the speed of the car or stops it. This is an example of dry fiction; here two solid, dry surfaces are used to create the friction. This is not the only use of friction in a car—several other components use it. For example – clutch discs. Friction clutches use the force of friction to engage and disengage the clutch facing with the flywheel. Several substances are used to make clutch discs—ceramics and organic resin compounds—to name a few. In the early days of automobiles, even asbestos was used for this purpose. Heavy-duty applications require clutch materials like ceramic while the other compound is used for less demanding usages. Whenever the frictional materials are used, the purpose is to generate friction and use it to our advantage.
However, there are places where we do not want any friction, and when we cannot get rid of it, we try to minimize it. Going back to the automobile example, we can take the engine. In an engine, a piston or a number of pistons move inside a bore. Here, friction is undesirable, so we coat the surfaces with a continuous supply of lubricants—this is lubricated friction.
Fluid friction occurs when two or more layers of fluid move in relative to each other and skin friction is the drag created between fluid and the skin of a body it rolls on.
Friction is a force so ubiquitous we do not realize its importance. We can walk on a surface, because there is friction between our legs and the surface. If there is no friction, walking will be dangerous—evidenced when try to walk on a wet surface. The liquid decreases the friction making the surface slippery, which causes us to fall. This just a simple example, there are many ways friction influences our daily life.
We use friction materials in numerous motion control products to put friction to our benefit or to minimize its impact. However, hate it or love it, friction is and will be there; we cannot avoid it.