Sound radiation efficiency of metals

Abstract

The purpose of this investigation was to determine the influence of controllable metallurgical properties on the radiated sound after impact using iron—manganese alloys and some forge hammer construction metals. The effect of metal properties on sound radiation can be characterized by the rate of attenuation of the sound, dp. For rectangular plate linear dimensions a and b. dp = 60[(ma)2 + (nb)2]Q−1(σ0Eh3rs)1/2 × {4.8498[σ0(1 − μ2)mprs]1/2 − 0.3536[(ma)2 + (nb)2] × Q−1(πEh3ms)1/2}−1 + C, dB/s, where E is elastic modulus, μ is Poisson's ratio, Q−1 is internal friction, σ0 is ultimate strength, p is the mass density, m, n is a mode number, h is the thickness of the plate, rs is the radius of the striker, ms is the mass of the striker. C is a constant accounting for the changes due to environmental scattering and absorption by the surfaces. The attenuation rate of sound radiation has been shown to be affected by the mechanical properties of the metal and geometry of solid collision. The mechanical properties can be modified by controlling the heat-treatment and the chemical composition of the metal, as well as its mechanical working.