Analysis of Metal Pick-Up Formation Process within Automotive Brake
Pad 05-13-01-0003
This also appears in
SAE International Journal of Materials and Manufacturing-V129-5EJ
Metal Pick-Up (MPU) is a problematic phenomenon in automotive disc brakes. MPU
generally forms as some metal lumps on the surface of the brake pad. If brake
pads have MPU, during braking they would cause grooving of the disc rotor,
generating brake noise and deteriorating the performance of the brake. The
previous literature has so far reported that the source of the MPU is an Fe
component from a disc rotor or brake pads. However, only a few of the generation
mechanisms of MPU have been proven. We investigate MPU to completely elucidate
the mechanism of MPU generation by using different analyses than the previous
literature.
First, to find out the source of MPU generation, we focus on the
chemical reaction of a certain component with wear debris during
braking, and some of the verification experiments are conducted
under the conditions of simulated friction interface.
Second, to clarify the change in the form of the MPU growth process,
the crystal structure of MPU is analyzed in detail by using the
world’s largest synchrotron radiation facility (SPring-8).
The results in this study reveal new facts about the source of MPU
generation and the MPU growth process that have so far only been supposed.