铁基形状记忆合金力学性能和激活回复性能研究

Experimental Investigation on Mechanical Properties and Activation-recovery Performance of Fe-based Shape Memory Alloys

摘要:

对研发的铁基形状记忆合金（Fe-based shape memory alloys，Fe-SMA）热轧板和冷轧板的力学性能和激活回复性能进行试验研究，得到了材料的力学性能基本参数和不同激活条件下的回复应力水平。研究发现，Fe-SMA材料具有很高的强度和优异的延展性。Fe-SMA热轧板的弹性模量均值为182GPa，抗拉强度1 136MPa，总延伸率45.0%。Fe-SMA冷轧板的弹性模量与热轧板相差不大，但冷轧板抗拉强度和总延伸率有所降低。在不同预拉伸应变与激活温度组合下，Fe-SMA的回复应力水平为165MPa~366MPa，可以满足目前工程应用中针对钢板裂纹修复和梁式结构承载能力提升的加固需求。与热轧板相比，Fe-SMA冷轧板在冷轧处理过程中形状记忆性能变差，反复升温激活过程中累积效应降低，因而热轧Fe-SMA更适用于需要多次激活补偿预应力损失的结构加固应用。Fe-SMA的基本材性指标和激活回复应力水平可以达到国际水准，但造价更低，适合于土木工程领域的加固应用。

Abstract:

An experimental study on the mechanical properties and activation-recovery performance of hot-rolled and cold-rolled Fe-based shape memory aloys （Fe-SMA） plate was carried out and presented herein. The basic mechanical parameters and recovery stress level under different activation conditions were obtained. The results indicate that the developed Fe-SMA exhibits strong strength and excellent ductility. The average elastic modulus of hot-rolled Fe-SMA plate is 182GPa， and its tensile strength is 1136MPa， while its total elongation is 45.0%. The elasticity modulus of cold-rolled Fe-SMA plate is basically equal with that of hot-rolled plate， but its tensile strength and total elongation are relatively low. The recovery stress level of Fe-SMA obtained under different combinations of pre-tension strain and activation temperature is 165MPa~366MPa， which can meet the requirements of engineering application for crack repair of steel plates and capacity improvement of beam structures. The shape memory performance of cold-rolled Fe-SMA plate deteriorates during cold rolling process， and the cumulative effect during repeated heating activation is reduced. Compared with cold-rolled Fe-SMA， hot-rolled Fe-SMA is more suitable for structural reinforcement applications that require multiple activations to compensate for prestress loss. On the comprehensive level， the basic material properties and activation-recoverystress of Fe-SMA studied in this paper can keep pace with international product levels of Fe-SMA. However， the Fe-SMA studied in this paper is more suitable for the rehabilitation application of engineering structures due to its low cost in comparison to the international products.