What new requirements do EV brake pads place on mineral fibres?
Abstract
Because of energy recovery, electric vehicles change the braking duty: the friction pad's working temperature range drops and usage frequency changes, raising new attention on corrosion sticking, NVH and brake dust for mineral fibres. This article reviews these new focus points; final fit still follows vehicle and bench validation.
EVs commonly use electric-drive energy recovery, so in everyday braking part of the torque is handled by the motor and the mechanical friction pad is used less often and with lower single-event energy — it takes over low-speed braking, emergency braking and supplementary braking when recovery is insufficient. This lowers the pad's overall working temperature range while raising the share of low-speed, light-load duty, shifting what to watch in the friction material and its mineral fibre.
Three new focus points. Corrosion sticking: at low temperature and light load, occasional rust-binding can occur between parking stops (the “click” on low-speed start); fibre dispersion and friction-layer stability affect the contact state, but sticking also depends on counterface protection, parking duty and overall formulation — not attributable to fibre alone. NVH: more low-speed light-load braking can bring low-frequency noise, so watch dispersion uniformity and friction-coefficient smoothness. Brake dust: users are more sensitive to wheel cleanliness, so watch low shot and abrasion control. Boundary: these are industry focus directions under EV duty, not a fit promise for a specific model; fibre indicators follow company data and the batch report, and final validation is on vehicle/bench.
Why a lower temperature range raises concern about corrosion sticking: when a pad works long-term at lower temperature and frequency, rust-binding can develop between the counterface and friction layer after a parked stop. As the skeleton, mineral fibre dispersion and friction-layer stability influence the contact state, but the phenomenon also depends on counterface protection, parking and overall design. On dust: coarse shot and high-abrasion components add dust and counterface wear; the industry friction basis suggests shot <5%, and Boer friction models are mostly <1–3% (subject to the batch report) — low-shot fibre helps at the raw-material source, though total dust still depends on formulation and counterface. Selection/validation: define the target model's energy-recovery strategy and pad duty; watch dispersion, shot and abrasion-related indicators; bench/vehicle-validate under low-speed light-load and supplementary braking; and follow batch stability before locking the design.
Key facts
- For: EV brake-pad formulators
- Change: energy recovery alters braking duty
- Focus: corrosion sticking / NVH / dust
- Basis: company product data; batch report; vehicle/bench validation
The original article is in Chinese; see the Chinese version for the full text. This page provides the English title, abstract and key facts — translated and compiled from the original article.