자동차용 브레이크 마찰재에서 고망간강의 마찰 및 마모특성

• Published in: Tribology and Lubricants Vol. 36; no. 2; pp. 88 - 95
• Main Authors: 정광기(Kwangki Jung), 이상우(Sang Woo Lee), 권성욱(Sungwook Kwon), 송명석(Myungsuk Song)
• Format: Journal Article
• Language: Korean
• Published: 한국트라이볼로지학회 2020
• Subjects: 기계공학; high manganese alloy(고망간강); cast iron disc(주철디스크); 1/5 scale dynamometer(1/5 스케일 다이나모미터); copper free(무동); friction material(마찰재); 1/5
• ISSN: 2713-8011; 2713-802X
• DOI: 10.9725/kts.2020.36.2.88

In this study, we investigate the mechanical properties of high manganese steel, and the friction and wear characteristics of brake friction material containing this steel, for passenger car application, with the aim of replacing copper and copper alloys whose usage is expected to be restricted in the future. These steels are prepared using a vacuum induction melting furnace to produce binary and ternary alloys. The hardness and tensile strength of the high manganese steel decrease and the elongation increases with increase in manganese content. This material exhibits high values of hardness, tensile strength, and elongation; these properties are similar to those of 7-3 brass used in conventional friction materials. We fabricate high manganese steel fibers to prepare test pad specimens, and evaluate the friction and wear characteristics by simulating various braking conditions using a 1/5 scale dynamometer. The brake pad material is found to have excellent friction stability in comparison with conventional friction materials that use 7-3 brass fibers; particularly, the friction stability at high temperature is significantly improved. Additionally, we evaluate the wear using a wear test method that simulates the braking conditions in Europe. It is found that the amount of wear of the brake pad is the same as that in the case of the conventional friction material, and that the amount of wear of the cast iron disc is reduced by approximately 10. The high manganese steel is expected to be useful in the development of eco-friendly, copper-free friction material.