Study On Recrystallization Texture Of Ni4WV Alloy Substrate For Coated Conductor

YBCO superconducting materials have great potential applications in the fields of information,military and so on.The good performance of metal substrate is very important for the preparation of YBCO.At present,Ni5 W is the most widely used metal substrate,it is capable of industrial production of 100 meters long strip,but it has a high ferromagnetism and hysteresis loss.In this paper,by means of alloying,some V elements are used instead of the 1% elements of W to obtain the better performance of Ni4 WV alloy substrate.In this experiment,3 kinds of Ni4WxV(x=2,4,6)alloys were prepared by vacuum induction melting.The composition was more uniform and the grain was refined by homogenizing annealing and hot forging;and the alloy substrates with thickness of 200?m were fabricated by rolling assisted biaxial texture substrate technology.The magnetic properties and yield strength of three kinds of substrates were measured.By using X-ray diffraction(XRD)and electron backscattering diffraction(EBSD),the cold rolling textures and recrystallization textures of different samples were analyzed and compared with that of the Ni5 W substrate to select the better comprehensive performance components.The results show that the increase of V content in Ni4 WV alloy substrate can increase the yield strength of substrate and reduce the ferromagnetic;The comprehensive performance of Ni4W2 V is best,its yield strength is 150.7Mpa,which is equivalent to Ni5W;The saturation magnetization is 55% of Ni5 W at room temperature,and the content of the cube texture is 47%(<30 degrees),which is a promising research alloy composition.In order to obtain a higher cube texture content,this experiment was carried out to optimize the recrystallization process of Ni4W2 V substrate.The effects of different final recrystallization temperature and the first step annealing temperature on the cube texture of the substrates were measured and compared.The results show that when the final recrystallization temperature of Ni4W2 V substrate is increased from 1100? to 1200?,cube texture content increased from 47% to 55%.The higher final recrystallization temperature is favorable for the growth of cubic oriented grains and the addition of other oriented grains.Through the microhardness curve,We determined that the initial recrystallization temperature range is from 600? to 700?,and the final Ni4W2 V recrystallized cubic texture intensity is measured in the first step annealing temperature at a temperature of 600?,650? and 700?.The results show that when the first step annealing temperature is 650?,the cubic texture of the substrate is the highest,which is 58%.This is because at the time of annealing at 650?,the substrate occursed partial recrystallization,the highest proportion of the cubic orientation of the crystal nucleus,which laid the foundation for the high-temperature annealing stage.In this thesis,the Ni4 WV alloy substrate with the best comprehensive properties was studied and the recrystallization process was optimized.It provides experimental basis and data for further research on Ni based alloy baseband.