Design for Homogeneity of Brake Discs to Reduce Judder, from R&D to Manufacturing

We studied the relationship between disc thickness variation (DTV) and casting material properties and clarified that the circumferential homogeneity of brake discs has significant effects on brake judder. As a solution, we established an integrated system for developing and manufacturing homogeneous brake discs to reduce judder by making the most of our integrated business process from R&D through manufacturing, including our in-house foundries. The system we developed consists of the following elements: foundry engineering to obtain homogeneous discs, an original flake graphite structure index (K-FGI) to measure the homogeneity of our products, and accelerated wear tests on a brake dynamometer to estimate the potential on-brake DTV growth.