10MA多支路汇流装置上钽的强度实验研究

Tantalum strength experiments on 10 MA facility

磁驱动准等熵加载技术通过电流产生的磁压力加载材料,加载路径由负载电流波形和负载结构决定。作为应变率介于静高压加载和冲击加载之间的新型实验技术,熵增小、温升低。10 MA装置是典型的多支路汇流装置,包括24个电流支路,可在较大范围内控制负载电流波形,实现mm厚、cm直径样品在不同应变率下的准等熵加载。基于10 MA装置,通过调节负载电流波形实现样品加载路径控制,在一定压力-应变率范围,开展金属钽的强度实验研究,获取了不同厚度金属钽样品的加-卸载波剖面速度历史,分析获得了钽在系列峰值压力下的强度数据,比较了多个加载平台不同加载路径下的强度数据,实验结果与美国圣地亚国家实验室的磁驱动准等熵结果接近(平均应变率都约为105 s−1),明显高于冲击加载的流动强度,低于准静态加载获取的流动强度,与应变率增高强度会有所下降的理论预测一致。基于多支路汇流装置,未来将可开展更为丰富的材料动力学特性实验研究。

In metal strength research under extreme conditions,material’s response is closely related to microstructure,stress history,pressure and temperature,etc.Magnetically driven isentropic compression as a new experimental technique with strain rate between quasi-static and impact loading,has low increased entropy and temperature.This paper presen the experimental work carried out on a 10 MA facility in CAEP using the new technique.The 10 MA facility includes 24 modules,which help to control the load current shape in a relative wide range.Based on the characteristics of the 10 MA facility,the sample loading path was controlled by adjusting the load current waveform.In a certain pressure-strain rate range,the strength of tantalum was tested.The loading and unloading wave profile velocity history of tantalum samples with different thicknesses was successfully obtained,and the strength data of tantalum under a series of peak pressures were obtained.Comparison shows that the strength obtained is significantly higher than the strength under shock loading,but lower than that under quasi static loading More experimental studies on material dynamic characteristics will be carried out at the facility in the future.