Manganese-Copper Alloys of High Damping Capacity

Abstract

That ageing is necessary to produce useful damping capacities in the manganese-copper alloys is known. A detailed correlation between damping and ageing variables has, therefore, been established, so providing a basis for the specification of material for particular operating conditions of stress and temperature. General relationships between ageing time and temperature, applied stress level, and ambient temperature of test have emerged. There is a change from decreasing to increasing damping capacity with stress as isothermal ageing time is increased and longer ageing times are required to reach the critical point at higher ambient temperatures. The change occurs after shorter times at higher ageing temperatures or higher manganese contents. The effects of age-hardening, nitrogen content, and homogeneity of composition have been shown to be of little practical significance.