Explanation of brake pad heat recession and burnishing problems
The problem of thermal degradation and abrasion of brake pad equipment is addressed here. Thermal failure refers to brake pads, or brake discs, the temperature rises to a certain extent, the brake effect of the phenomenon of decline or even failure, which is quite dangerous, so the critical temperature of thermal failure is very important, the obvious feeling is the brake foot soft, and then how to step on the brake effect is not obvious. Different brake pads have different heat fade temperatures, the original brake pads are generally 250 ℃ -280 ℃, and good brake pads at least 350 ℃ or more, which one is more reliable you can imagine.
When the brake intensity and time continue to increase, the temperature continues to climb, then the internal material of the brake pads will undergo chemical changes, resulting in changes in the molecular structure and thus affecting the braking effect, which is known as ablation.
The symptom of ablation is that the leather surface is bright crystal mirror-like, which is the structure of high-temperature crystallisation of the brake pad material after ablation. After the heat recession cooling brake pads will naturally restore the braking ability, but abrasion is not the same, it is irreversible. Brake pads, but the occurrence of erosion of its braking ability almost completely lost, in order to ensure safety must be dealt with immediately, the situation is light with sandpaper grinding heavy can only be replaced.
Determination of the thickness of brake pads for smaller use is also based on a number of factors, including the braking system itself (caliper or cylinder piston design stroke, regulator clearance, brake pedal clearance, etc.). The type of brake pads (asbestos, semi-metallic, NAO, special fibres), the assembly of the brake pads and brake shoes, and so on.
For example: the bonded connection is usually processed at high temperature, and the anti-wear performance of the pads is higher than that of the riveted ones, because when the riveted pads are worn to the point that the rivet heads are exposed, the rivets will directly damage the brake discs or drums. In contrast, bonded pads can be worn to the point where the metal layer is exposed, and only at that point does metal-to-metal friction result in a harsh noise.
