【摘要】 本研究以国际热核聚变反应堆(International Thermonuclear Experimental Reactor,ITER)磁体极向场用NbTi超导线材的性能优化为目的,通过TEM研究热处理工艺对NbTi超导线材微观组织及4.2K温度下临界电流的影响。结果表明,具有高Jc值的NbTi在4.2K条件下析出具有典型形貌的α-Ti钉扎中心,即弥散分布于β-NbTi基体上,高度褶皱及卷曲。较高温度的热处理有利于4.2K下Jc的提高,但增加热处理次数使Jc值略微降低。更多还原

【Abstract】 This paper shows the results of R&D program carried out to optimize NbTi wires for the Poloidal Field (PF) coils of ITER. The influence of heat treatment on the microstructure was investigated by using TEM to find the relations between the microstructure and the critical current densities at 4.2 K for NbTi superconducting composite wire. Typical microstructure (in transverse cross-section) shows α-Ti pinning centers dispersed within the superconducting β-NbTi matrix with strong fold and curl for the NbTi wire with high critical current density at 4.2 K. It is believed that the higher temperature is beneficial to a higher Jc value at 4.2 K, but the Jc values slightly decrease with increasing the heat treatment times.更多还原