抄録
Effects of the Si content and Si crystalline size on damping property of Powder Forged (P/F) Al-Si alloys were investigated by a Fast Fourier Transformation (FFT) analyzer. A quantitative image analysis method was successfully used to determine a mean diameter and distribution of Si crystals in the aluminum alloy. The damping capacity δ strongly depends on the mean diameter of Si crystals. δ of heat treated specimens with Si crystals of 2 to 5 micron meters is 4 to 25 times smaller than that of as-forged specimens with those of 1 to 5 micron meters. It indicates that the vibration occurred by knocking on the specimen is absorbed at boundary between Si particles and aluminum matrix. Therefore, fine distribution of Si crystals and/or elimination of crystal coarsening contribute to the good damping property.
