【摘要】 针对初始SME(shape memory effect)和PE(pseudo-elastic)状态TiNi合金试样,采用带有红外测温系统的SHPB冲击压缩装置,实时测量了冲击相变过程中两种材料试样表面瞬态温度,并根据实验结果计算了相应的温度变化。实验结果表明,冲击加载相变过程中,温度随相变应变的增大而升高,当应变最大时,温度最高;卸载过程中,对初始PE状态试样,温度降低,对初始SME状态试样,温度保持最高温度不变或降低,这同加载最高温度有关;卸载完成后,两种试样温度均高于其初始温度。计算温度结果表明,相变耗散功对加、卸载相变过程中温度变化的作用不可忽略。更多还原

【Abstract】 Aimed to two kinds of TiNi alloy,that is,initial shape-memory effect TiNi alloy and pseudo-elastic TiNi alloy,the transient temperatures at the surfaces of the TiNi alloy specimens were measured during dynamic deformation in real time by using the compression split Hopkinson pressure bar device with an infrared detector system.And the corresponding temperature changes were calculated according to the experimental stress-strain curves.Temperature-measurement results indicate that significant temperature change was observed in the process of phase transformation.Specifically,during loading,the temperature increased with the increasing of the phase transformation strain,and reached its highest at the highest phase transformation strains.While during unloading,for the initial pseudo-elastic specimens,the temperature decreased significantly,in contrast,for the initial shapememory effect specimens,the temperature kept the highest temperature constant or dropped,which is depended on the highest loading temperature.After a cycle of loading/unloading,the temperatures of the specimens with two initial states are higher than their initial ones.The calculated results show that the effect of transformation dissipation work on the temperature change can not be ignored.更多还原