Abstract
Flake graphite cast iron is a high damping metal. Cast iron is used for engine block and brake materials in the automobile industry due to its low cost and high abrasive characteristics. High drivability characteristics of automobiles such as silence and effective braking ability are becoming more and more important recently. Since the anti-brake squeal materials are therefore needed for the brake materials, we studied the influence of graphite morphology and matrix on the damping capacity of hypereutectic cast iron.
The results charified that the damping capacity of the cast iron has good correlation with the graphite shape factor Ko, length of periphery of a graphite divided by the square root of the area, and kind of matrix. The damping capacity increases with the Ko value. This means that longer and thinner graphite promotes high damping capacity. Moreover, if the matrix consists of small amounts of martensite and bainite, up to 10%, with pearlite, the damping capacity increases with the fraction of the martensite and bainite.
