The effect of carbon on the loss of room-temperature damping capacity in copper-manganese alloys

Abstract

A high damping Cu-Mn alloy with a nominal composition of 48Cu-48Mn-1.5Al-0.27Si-0.072Sn-0.028C-0.05Er (all compositions in wt pct) was studied to determine the mechanism of the loss of damping capacity during room-temperature storage. In this study, it was found that an Er-modified alloy sample that was artificially aged for 16 hours at 400 ЊC was stable even after 68 weeks of room-temperature storage. However, a loss of damping capacity was exhibited in the same material when aged to produce an underaged or peakaged condition. The decrease in damping capacity was found to be thermally activated with at least three relaxation processes. Each of the three relaxation processes appear to be related to the diffusion of carbon within the Mn-rich regions and a single activation energy of 0.970 ‫ע‬ 0.05 eV was used to model these processes. Rapid loss of damping capacity was observed in the same alloy when doped with excess carbon. After 3 weeks of storage at room temperature, the damping of the carbon-doped material, artificially aged at 400 ЊC for 4 hours, was reduced to one-third of its initial damping capacity.

Snoek-type damping performance in strong and ductile high-entropy alloys

“…In addition, these irreversible relaxation processes accelerate when the service temperature increases. This means that structural stability and the high-temperature damping capacity of traditional noise reduction alloys are often insufficient for long-term use (8,9). Moreover, those internal structural features that create high damping ability (mobile defects) scale inversely with mechanisms that lead to good mechanical strength (immobile defects).…”

Mechanism of heat-induced damping attenuation for Fe-added Mn–Cu–Al alloys

“…Alloying is often regarded as an efficient method to improve the phase stability. Laddha et al mentioned that the element of Fe, as an alloying element, affects the FCC phase stability and the phase transition kinetics in Mn-Cu alloys [4]. Furtherly, Sakaguchi et.…”

Effect of the Precipitated Second Phase during Aging on the Damping Capacity Degradation Behavior of M2052 Alloy

“…[1][2][3][4][5] However, the MnCu based alloys showed an undesired problem that their damping capacity degraded when they were stored below Ms for a long time. [6][7][8][9] In a solution-treated Mn70Cu30 (wt.%) alloy, the damping capacity decreases to half of its original value after storing at 100℃ for 100 hours. [6] Similar results were observed in other MnCu damping alloys, such as Mn-22Cu (wt.%), Mn70Cu30(wt.%) SONOSTON alloy (Mn-36.2Cu-3.49Al-3.04Fe-1.17Ni wt.%), and INCRAMUTE alloy (Mn-48.1Cu-1.55Al-0.27Si wt.%).…”

“…[6] Similar results were observed in other MnCu damping alloys, such as Mn-22Cu (wt.%), Mn70Cu30(wt.%) SONOSTON alloy (Mn-36.2Cu-3.49Al-3.04Fe-1.17Ni wt.%), and INCRAMUTE alloy (Mn-48.1Cu-1.55Al-0.27Si wt.%). [7][8][9] The degradation of damping capacity is detrimental to the application of Mn-Cu alloys, which makes it a urgent issue to tackle.…”