What is the relationship between brake friction pad life and hardness?
Too high or too low coefficient of friction of brake friction plate will affect the braking performance of the car. Especially when the car needs emergency braking at high speed, too low a coefficient of friction will result in insensitive braking, while too high a coefficient of friction will result in tyre locking, which will cause the vehicle to tailgate and skid, posing a serious threat to driving safety.
According to the national standard, the suitable working temperature of the brake friction plate is 100~350℃. But many low-quality brake friction pads in the temperature reaches 250 ℃, its coefficient of friction will be sharply reduced, and at this time the brake will be completely out of order. Generally speaking, according to SAE standards, brake friction disc manufacturers will choose FF level rating coefficient, that is, friction rating coefficient 0.35~0.45.
The life of brake friction pads is not necessarily related to the surface hardness. However, if the surface hardness is high, the actual contact area between the brake friction pad and the brake disc is small, which often affects the service life. And the main factors affecting the service life of brake friction pads include hardness, strength, and abrasiveness of friction materials. In general, the life of the front brake friction pad is 30,000km, and the life of the rear brake friction pad is 120,000km.
It is often caused by the deformation of brake friction pads or brake discs, which is related to the material of brake friction pads and brake discs, processing precision and use of heat deformation, and the main reasons are uneven thickness of brake discs, poor roundness of brake drums, uneven abrasion of brake friction pads, as well as thermal deformation and hot spots.
In addition, the deformation or improper installation of brake calipers and the unstable friction coefficient of brake friction pads can also cause shaking during braking. In addition, if the vibration frequency generated by the brake friction pads during braking resonates with the suspension system, shaking can also occur.
