EFFECT OF SMALL ALLOYING ADDITIVES ON FORMATION OF Nb_3Sn LAYER
LI Shaoguang TANG Quanhong SONG Juyi ZHU ANG Xianglin
Cite this article:
LI Shaoguang TANG Quanhong SONG Juyi ZHU ANG Xianglin. EFFECT OF SMALL ALLOYING ADDITIVES ON FORMATION OF Nb_3Sn LAYER. Acta Metall Sin, 1987, 23(1): 50-56.
Abstract The thickness,diffusion rate,grain size and structure of the Nb_3Sn layer prepared by modified bronze process have been examined by means of metallog- raphy,SEM,X-ray diffraction and EMPA.Both Small amount of Mg,A1 or Y added to the Cu-7at.-%Sn matrix and 1wt-% Zr added to the Nb care may ac- celerate the rate of formation and refine the grain size of the Nb_3Sn layer.The effect of addition of either 0.1—0.5 at.-% Mg to bronze or 1 wt-% Zr to Nb core is most predominante among them:The A1 added up to 1 at.-% may cause the bronze to work hardening and the specimen to premature failure under defor- mation.The structure of Nb_3Sn layer formed is of A15 type as shown by X-ray diffraction.Only trace Cu is found in Nb_3Sn layer nearby bronze,but Mg or A1 is enriched in the bronze matrix near the bronze/Nb_3Sn interface.In Nb_3Sn layer trace Mg or A1 is detected.Zr may diffuse from Nb core into bronze ma- trix in certain amount.
