A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on t...A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on the microstructures, intergrain connections, and related superconducting properties were systematically analyzed. The modified SPS process can not only increase the final density of the bulk samples but also enhance the texture structures. Clean grain boundaries were obtained instead of the intergrain amorphous layers. Therefore the intergranular properties were obviously improved. Due to the better intergrain connections and the stronger flux pinning properties, the critical current densities of the Bi-2212 bulks obtained via the modified SPS process were greatly increased. The obtained improvements imply the possibility for the modified SPS technique to be used for enhancing the superconducting properties of the Bi-2212 tapes.展开更多
使用MMS-200热力模拟实验机研究了工程用铸态退火2024合金(φ247 mm)在不同温度下的变形行为,建立了热变形的本构方程和DMM(Dynamic material model)加工图。分析了铸锭退火态、等温挤压及等温挤压退火实验件的微观组织和力学性能,结果...使用MMS-200热力模拟实验机研究了工程用铸态退火2024合金(φ247 mm)在不同温度下的变形行为,建立了热变形的本构方程和DMM(Dynamic material model)加工图。分析了铸锭退火态、等温挤压及等温挤压退火实验件的微观组织和力学性能,结果表明:根据DMM加工图确定的热变形温度395~450℃和应变速率0.01~0.1 s^(-1)工艺,可制备出组织明显细化、力学性能优异的大挤压比2024铝合金等温挤压件。展开更多
基金Project supported by the National Basic Research Program of China(Grant No.2011CBA00104)the National Natural Science Foundation of China(Grant No.51472206)+1 种基金the ITER Project of China(Grant No.2013GB110001)the Program for Innovative Research Team in Shaanxi Province,China(Grant No.2013KCT-07)
文摘A modified spark plasma sintering（SPS） technique was developed for the fabrication of Bi2Sr2CaCu2Ox（Bi-2212）superconducting bulks with better intergrain connections. The influences of the modified SPS process on the microstructures, intergrain connections, and related superconducting properties were systematically analyzed. The modified SPS process can not only increase the final density of the bulk samples but also enhance the texture structures. Clean grain boundaries were obtained instead of the intergrain amorphous layers. Therefore the intergranular properties were obviously improved. Due to the better intergrain connections and the stronger flux pinning properties, the critical current densities of the Bi-2212 bulks obtained via the modified SPS process were greatly increased. The obtained improvements imply the possibility for the modified SPS technique to be used for enhancing the superconducting properties of the Bi-2212 tapes.
基金National Key Basic Research Program of China("973"Program)(2011CBA00104)the International Scientific and Technological Cooperation Projects of China(S2010GR0518)the National Natural Science Foundation of China(51102198)
文摘使用MMS-200热力模拟实验机研究了工程用铸态退火2024合金(φ247 mm)在不同温度下的变形行为,建立了热变形的本构方程和DMM(Dynamic material model)加工图。分析了铸锭退火态、等温挤压及等温挤压退火实验件的微观组织和力学性能,结果表明:根据DMM加工图确定的热变形温度395~450℃和应变速率0.01~0.1 s^(-1)工艺,可制备出组织明显细化、力学性能优异的大挤压比2024铝合金等温挤压件。
