Remarkable improvement in damping capacity of M2052 alloy by step-cooling treatment

In order to efficiently produce high-damping Mn-Cu based alloys, different heat treatment processes were designed in this study, and the influence of the cooling process on the damping property of M2052 alloy was systematically investigated. The results show that the step-cooling process significantly influenced the damping performance of M2052 alloy. Compared with M2052 alloy processed using air-cooling with an internal friction (tan δ) of 0.087 at a strain amplitude λ = 5 × 10−4, the damping capacity was improved by more than 49% through the step-cooling treatment. This was mainly because of the increment of manganese content of in the Mn-rich regions, which is caused by the spinodal decomposition on the low temperature side of the miscibility gap. Meanwhile, the step-cooling treatment significantly suppressed the precipitation of -Mn, which reduced the negative effect of -Mn on the damping capacity and kept the Mn content in the Mn-rich regions at a high level. The step-cooling treatment, a novel and effective microstructure control process, provides a new method for the efficient preparation of high-damping M2052 alloy.