摘要
提出了一种相变超塑性扩散焊与扩散钎焊结合起来的复合工艺-相变-扩散钎焊(T/DB).以低碳钢为母材、镍基非晶箔带(BNi2)为中间层,在更高峰值温度(1200℃)下试焊.结果表明,尽管高温停留时间短、且循环次数仅3次,仍获得了合格的接头.能谱分析可知焊后残留中间层中心区Fe含量高达约60％-70％;扩散入母材的Ni主要存在于母材的层片状珠光体区域.表明Ni在母材内的扩散通道优先选择含有大量相界面的区域进行扩散.将相界扩散分为动态相界扩散与静态相界扩散;论证了T/DB工艺中的高效扩散与相界扩散密切相关.
A new bonding method combining transformation superplastic diffusion bonding with diffusion brazing (T/DB) is proposed. A welding experiment was performed using a low carbon steel as base metal and BNi2 amorphous foil as interlayer at 1200degreesC. The results are as following: Although the time at elevated temperature is shortened and the number of temperature cycles is reduced to 3, a mechanically sound joint can be obtained easily. The content of Fe at the center of residual interlayer is increased to about 60%-70%, and in the region of base metal adjacent to welded interface, the Ni atoms diffused into the base metal almost mainly exist in the lamellar pearlite of base metal from the EDXS point analysis, which shows the significant selectivity for Ni atoms diffusion path. Furthermore, the phase boundary diffusions are classified as steady phase boundary diffusion and dynamic phase boundary diffusion, and the higher diffusion rate in the T/DB process is attributed to fully utilize phase boundary diffusions and to suitably utilize bulk diffusion.
出处
《金属学报》
SCIE
EI
CAS
CSCD
北大核心
2004年第6期653-658,共6页
Acta Metallurgica Sinica
关键词
低碳钢
BNi2非晶带
相变超塑性扩散焊
扩散钎焊
相界扩散
low carbon steel
BNi2 amorphous foil
transformation superplastic diffusion bonding
diffusion brazing
phase boundary diffusion
