Influence of Nb on Co-based brazing filler metal

被引：0

作者：

机构：

[1] Powder Metallurgy and Special Materials Department, General Research Institute for Nonferrous Metals

来源：

Zhang, X. (zxycqy71926@163.com) | 1600年 / Editorial Office of Chinese Journal of Rare Metals卷 / 37期

关键词：

Brazing; Cathode; Co-based brazing filler metal; Niobium;

D O I：

10.3969/j.issn.0258-7076.2013.05.011

中图分类号：

学科分类号：

摘要：

The cobalt-tungsten-niobium ternary alloy welder of Co:W:Nb=65:25:10(%, mass fraction) was studied based on the WCo75 brazing filler metal and referring to Co-Nb and Nb-W binary phase diagram. The proportion is designed for the proper temperature and fitting to the cathode welding standard at the same time. The WCo75 and Co-W-Nb brazing filler metals' melting point, wettability, the morphology and composition of the welding line were tested, analyzed and contrasted. Meanwhile, the influence of Nb to the WCo75 was discussed. The results showed that the melting point was markedly lowered from 1480.0 to 1238.5°C, and the contact angle was signally decreased from less than 20° to about 5° by adding Nb. A good welding result was gotten after welding without cracks, corrosion or liquation. Some concentration phases were found in weld structure after brazing (the cobalt-rich phase was close to the free end while the tungsten-rich phase was next to the matrix). And diffusion between the brazing filler metal and the base metal could be observed. By adding Nb, on the one hand, the element concentration trend would not change; on the other hand, it could improve W diffusing into the Mo base metal. Meanwhile, the emission efficiency of cathode would not be affected for being polluted or poisoned.

引用

页码：744 / 749

页数：5

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