机械合金化制备Nb_3Al超导体的工艺研究

Fabrication of Nb_3Al Superconductor by Mechanical Alloying

利用机械合金化方法制备了一系列不同的Nb3Al块材,研究了球磨时间及退火温度对Nb3Al超导体成相及超导性能的影响,并采用X射线衍射仪、扫描电子显微镜和磁学测量系统等详细分析了不同制备条件下Nb3Al超导体的相成分、微观组织结构,以及超导性能的变化.结果表明:将Nb和Al粉末混合后,利用高能球磨设备,球磨1 h即可以生成Nb(Al)ss过饱和固溶体;当球磨时间增加到10 h时,样品粉末发生了非晶化.通过调节球磨时间、退火温度,成功制备出超导起始转变温度达到15.3 K的单相Nb3Al超导体.

By fabricating a series of different mechanical alloying Nb3A1 bulks, the effects of milling time and annealing temperature on Nb3A1 phase formation were investigated. X-ray diffraction, scanning electronic microscope and magnetic property measurment system were used to analyze the phase composition, microstructure and superconducting properties of the Nb3A1 samples fabricated on different conditions. The results suggested that Nb-A1 supersaturated solid solution was synthesized by mechanical alloying method as long as the stoichiometric elements powder was ball milled for 1 h, and when the ball milling time was up to 10 h, the blended powder would transform to amorphous phase. By optimizing the milling time and annealing temperature, single Nb3A1 superconductor bulk was obtained successfully and its onset transition temperature was 15.3 K.