Mechanism of volume viscosity in the liquid metal system lead‐bismuth

Ultrasonic measurements in the Pb–Bi liquid metal system show that volume viscosity in these alloys differs from that observed in the pure metals Pb and Bi. The excess absorption in the alloys exceeds that in either of the pure metals at low temperatures and decreases with increasing temperature. We suggest that this absorption is due to two effects: (1) a structural volume viscosity similar to that observed in pure Pb and Bi; and (2) a volume viscosity due to concentration fluctuations.