Pad Brek Kenderaan Persendirian: Kajian ke atas mikrostruktur lapisan pindah

Abstract

Mikrostruktur permukaan bahan geseran brek beransur berubah dengan peningkatan masa pembrekan dan beban kenaan. Setiap sampel menjalani ujian geseran dengan lima beban kenaan (100 N, 200 N, 400 N, 600 N, 800 N) dan masa pembrekan yang berlainan (3, 6, 9, 12, 15 minit). Perubahan permukaan sampel diperhatikan selepas setiap kali menjalani ujian geseran dengan menggunakan teknik kemikroskopan elektron imbasan. Pada permulaan pembrekan, proses adunan bahan pindah berlaku. Pembrekan seterusnya menyebabkan berlaku urutan perubahan lapisan pindah seperti berikut; (i) pembentukan tampalan pindah, (ii) penjanaan lapisan menutupi permukaan secara menyeluruh, (iii) pembentukan lapisan pindah berbilang, dan (iv) lapisan pindah paparan lebur. Penelitian ke atas bahan yang dikaji menunjukkan darjah perubahan permukaan haus menjadi lebih intensif dengan peningkatan masa pembrekan dan beban kenaan. Kata kunci: pad brek; ujian geseran; MEI; tampalan pindah; lapisan pindah Surface microstructures of brake friction materials gradually change with increase in braking time and applied loads. Each sample is subjected to five different applied loads (100 N, 200 N, 400 N, 600 N, 800 N) and braking times (3, 6, 9, 12, 15 minutes). The surface changes were observed after each friction test by using scanning electron microscopy technique. A process of mixed transfer materials was observed upon the onset of braking. With subsequent brakings, the following sequence of changes on transfer materials was observed; (i) formation of patches of transfer material, (ii) generation of continuous transfer materials, (iii) formation of multilayer of transfer materials, and (iv) formation of transfer material that behaves like a fluid. Investigation on the SEM micrographs showed that the degree of surface changes became severe with increase in braking times and applied loads. Key words: brake pad; friction test; SEM; transfer patches; transfer layers