钎焊间隙对镍基非晶态及晶态钎料接头强度的影响

THE INFLUENCE OF BRAZING CLEARANCE ON JOINT STRENGTH OF NICKEL BASED AMORPHOUS AND CRYSTALLINE BRAZING FILLER METALS

系统研究了Ni_(82.5)Cr_7Si_(4.5)B_3Fe_3成分的非晶态及晶态钎料在不同的钎焊规范下真空钎焊1Cr18Ni9Ti不锈钢时接头强度随钎焊间隙变化的特征及与钎缝组织的对应关系.结果表明,接头强度随钎焊间隙的变化存在平台值现象,平台对应的两个特征钎焊间隙分别称为最小可用钎焊间隙(W_(min))和最大可用钎焊间隙(W_(max));从保证填缝质量及成形来看,W_(min).不应小于0.01mm;从避免钎缝中出现脆性化合物相及获得较高接头强度考虑,钎焊间隙选择不应大于W_(max);在两个特征钎焊间隙内,钎焊间隙变化对接头强度影响不大;钎焊温度或钎焊保温时间增加时,最大可用钎焊间隙也增大,而最小可用钎焊间隙基本保持不变.

The systematic researches on the characteristics of brazed joints strength vs brazing clearance for 1Cr18Ni9Ti stainless steel vacuum brazed with amorphous and crystalline Nickel-based (Ni82.5Cr7Si4.5B3Fe3) brazing filler metals at different brazing variables have been made, and the relationship between brazement structure pattern and brazed joint strength has also been investigated. The experimental results indicate that there exists the 'strength platform' in the curves of brazed joint strength changing with brazing clearance, the two characteristic brazing clearances corresponding to the 'strength platform' in the curves are called the minimal usable brazing clearance Wmin and the maximal usable brazing clearance Wmax. From the point of obtaining good joint filling quality and formation, the brazing clearance should not be less than 0. 01 milimeter; and from the view of making brazement free from brittle compound phases and getting high joint strength, the brazing clearance can not be larger than the critical clearance WCB. There are very small changes on brazed joints strength when the brazing clearance changes within the two charateristic clearances. From the experimental results, it can been found that Wmax increases and Wmin remains stable when brazing temperature rises or brazing time is added.