ピアノフレーム用ねずみ鋳鉄の音響特性に及ぼす基地組織の影響

抄録

  Two antagonistic properties i. e., higher modulus of elasticity and higher damping capacity are required simultaneously to piano frame with gray iron castings. With a view of improving the quality of present frame, damping capacity, natural frequency and power spectrum of gray cast iron specimen were analyzed by measuring the sound emission when the center of the specimen held at two fixed positions by tungsten wires was hammered on specially designed experimental apparatus. From results obtained, it has been clarified that the changing of matrix to ferritic from pearlitic raises damping capacity, but decreases power spectrum. The changing of matrix to pearlitic or martensitic from ferritic, however, lowers natural frequency which has been thought as the parameter of modulus of elasticity of cast iron.