锰基高强度高塑性高阻尼形状记忆合金的性能研究

Characteristic of High Strength,High Plasticity and High Damping Shape Memory Mn-Based Alloys

采用磁悬浮熔炼、测定试样形状记忆效应（SME）和双程形状记忆效应（TWSME）、金相法、示差量热分析（DSC）、断口形貌观察和自由震动波衰减曲线等方法研究了高强度高塑性高阻尼Mn基形状记忆合金的记忆特性以及Cu、Ni、Fe、Cr、Ti、N等元素对合金性能的影响。结果表明，Cu溶入越多，合金的SME越高；适当的时效热处理可强化合金提高其SME；含Ti、N元素的合金的SME最好，回复率达73％，TWSME回复率达21％。所研究的合金都有明显的双程形状记忆效应。淬火状态的合金有高的塑性，延伸率达25％，并有良好的阻尼抗震能力。淬火时效状态的合金有高的强度极限，尤其是高的屈服极限（σ=320～475MPa）、适当的塑性（δ为4．2％～5．0％），合金元素还能提高所研究合金的抗氧化和抗腐蚀能力。

The Mn-based shape memory alloys with high strength, high plasticity and high damping were prepared. The effects of alloy elements (Cu,Ni,Cr,Fe,Ti, N) on shape memory characterization, tensile properties and temper heat treatment were investigated ,using magnetic suspension melting, determining shape memory effect(SME), metallography, DSC of specimen, SEM of fracture surface and free decay curve of vibration wave. The results showed that higher contents of Cu increased the shape memory effect (SME); temper heat treatment improved the SME of tested alloys,but raised the martensite transformation temperature. The alloy containing Ti and Ni possessed the best SME among the three,and the shape recovery rate was up to 73%. All the tested alloys had excellent two-way SME, the TWSME of alloy 3 (Mn -Cu50-Ni5-Cr0.5-Fel-Til-NO.1)was up to 21%. The alloy in quenching state had high plasticity and good workability. The alloys in quenching and tempering state had higher strength, especially high yield strength (σ6=320-475 MPa) and suitable plasticity(δ≥4.2% -5.0%),so it should have higher fracture toughness. The tested alloys possessed good damping ability and good anti-oxidation and corrosion resistant characteristics.