history and quality of brake friction products
Due to their ability to dissipate heat and high durability, most of the clutch discs, brake shoes, and disc brake pads before the 1970s were made of asbestos-based material. This led to the creation of dust as a byproduct. There are numerous hazards associated with these kinds of brakes which made it necessary for manufacturers to find an alternative which can not only deliver a high friction coefficient but is also flexible enough with similar features. As a result, three types of replacement linings emerged- ceramic, non-asbestos organic and semi-metallic.
Amongst all, non-asbestos was the first one to be used in automotive production. The fibers of this type of vehicle friction product are bonded together by pressure and are made up mostly coconut shells.
In semi-metallic lining, the metal content is usually higher. This gained a lot of popularity in the disc brake equipped vehicles in the late seventies. They were especially used in front wheel drive cars with front disc brakes performing around 80 % of the braking job. Hence, the lining became a lot more durable and dissipated heat a lot more effectively.
These differences in lining led to rotors which were very easily distorted by heat and the need for frequent servicing for the front brakes to work efficiently. Noise emerged as another issue at times when linings were wet or required replacement. This led automotive brake shoe exporters and friction products manufacturers to search for alternatives and there was the emergence of ceramic-based friction materials in the late 80s.
Ceramic friction material usually consists of two materials-
a) Copper –which prevents metal-to-metal wear and promotes heat dissipation.
b) Space age technology ceramic fibrous material- which reduces the brake noise and provides rigidity.
Another advantage of ceramic material is that it produces negligible dust. This is highly useful for cars with aluminum or magnesium wheels as well as cars with steel spoke wheels. It makes the wheel maintenance a lot easier. The ceramic-based friction material is used in most of the vehicles today whereas cars with rear drum brakes still use non-asbestos organic materials.
So, the next time you are faced with multiple options for parts with no difference except in terms of price, take a good look and choose the vehicle friction products which best suits your needs. Going for ceramic ones is highly recommended, keeping in mind their usefulness.