This study presented an alumina-based coating prepared using a plasma electrolytic aluminating (PEA) method. The technology addressed the important topics of brake wear reduction and improvement of corrosion resistance, especially important for electrical vehicles (EV). A commercial EV cast iron brake disc with the alumina-based coating was tested with two modified AK Master dynamometer tests under SAE Brake Dynamometer Standards J2522. In the first test, the number of stops in the Fade sections were reduced from 15 to 6 to maintain the test temperature below 500 °C. Such Fade tests were repeated two times. Weight loss of tested brake disc and pads were then measured. After measurements, the tested components were installed back to the dynamometer to run additional normal Fade (sections 9 and 14, 15 stops each with temperature up to 580 °C) and Recovery (sections 10 and 15) tests. The Characteristic Value coefficient of friction (COF) during testing was around 0.38-0.48. The COF was quite stable at 0.33-0.35 in all Fade sections. In the first part of the dynamometer test, the brake pads lost weight of 6.1 g (inboard) and 6.8 g (outboard) while the tested brake disc lost a weight of 2 g. After the additional test, the weight loss on the top of the previous test was 4.5 g and 3.7 g for inboard and outboard pads, respectively, and the disc only lost 0.5 g more. Comparing to a tested stock disc baseline, typical pad and disc weight loss were 21 g and 14.5 g. The significant reduction in wear is attributed to adhesive friction mechanism instead of abrasive wear behavior.
University of Windsor: Prof. Dr. Xueyuan Nie; Ms. Ran Cai, Ms. Jingzeng Zhang, Dr. Jimi Tjoing; NUCAP Industries: Mr. Sean Foots, Mr. Mark Lavelle