1. Asbestos brake pads
As the name suggests, asbestos brake pads are brake pads made of asbestos-containing brake pads (of which asbestos is 40%-60%). Because of its low cost and light weight, many vehicle production companies still use asbestos-containing brake pads when producing cars such as trucks and construction vehicles. Because brake pads collide with dust during work, and release harmful substances to pollute the environment, many countries in the world have now banned the use of asbestos products.
2. Semi-metal brake pads
The “semi-metal” hybrid brake pads (Semi-met) are primarily made of rough steel wool as a reinforcing fiber and an important mixture. From the appearance (fine fibers and particles), it is convenient to distinguish between asbestos-type and non-asbestos organic-type brake pads (NAO), and they have a certain magnetic property. His primary strengths are its temperature control capability and high braking temperature. The poor heat transfer function of the asbestos type is compared with the cooling capacity of the brake disc and the brake drum. They assist the brake disc and brake when braking. The drum emits heat from its exterior and heat is transferred to the brake shoes or brake calipers and their components. The composition of the material generally contains about 30% to 50% of iron metal materials (such as steel fiber, reduced iron powder, foamed iron powder). The semi-metallic conflict data was named after it. It is the first asbestos-free material developed to replace asbestos. Its characteristics: good heat resistance, high absorption power per unit area, large thermal conductivity, can be applied to the braking conditions of cars in high-speed, heavy-duty operation. However, it has defects such as large braking noise and brittle corners.
3. Less metal brake pads (copper fiber brake pads)
In a broad sense, the conflicting data in the metal brake pads contains two or more kinds of fibers (with inorganic fibers and a few organic fibers). He has the strength of a semi-metallic brake pad and the brake noise is relatively small.
4. Carbon fiber, ceramic brake pads
The ceramic brake pads are driven from the principle of cermet instead of non-metallic ceramics. When the brake pads are strongly braked at high speed, the high temperature occurs in the conflicting appearance. According to the measurement, it can reach 800-900 degrees, and some even higher. At this high temperature, the surface of the brake pad will have a similar reaction to the cermet sintering, so that the brake pad has excellent stability at this temperature. However, the conventional brake pad does not have a sintering reaction at this temperature, because the sharp rise in the external temperature causes the surface material to melt and even the air cushion, which causes a situation in which the brake function of the continuous brake is drastically lowered or the brake is completely lost.