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通过高能喷丸方法在工业纯钛表面制备了纳米表层,选择B-Ag40CuZnCdNi钎料对纳米化前后的纯钛进行了不同工艺的钎焊,借助微观组织分析和抗剪强度测定研究了表面自身纳米化对工业纯钛钎焊过程的影响。结果表明:用B-Ag40CuZnCdNi钎料钎焊工业纯钛时,表面自身纳米化预处理提高了母材表面的活性,促进了纯钛母材向液态钎料中的溶解,低温短时焊接时对接头性能提高有利,接头强度比未预处理时提高了13.8%。焊接温度超过650℃后,母材纳米表层的高活性使界面区的金属间化合物层增厚,接头性能反而下降;由于在焊接温度下元素的固态扩散不易进行,纳米化前处理对液态钎料中的元素向母材扩散的影响不明显;母材纳米化前处理后,钎焊时通过降低焊接温度和缩短保温时间,既可发挥纳米表层有益特性,同时避免不利影响。
Nanostructured surface was prepared by high-energy shot peening. B-Ag40CuZnCdNi brazing filler metal was used to braze the pure titanium before and after nanocrystallization. The microstructure and shear strength were used to study the surface nano- Impact on the industrial pure titanium brazing process. The results show that when the pure titanium is brazed with B-Ag40CuZnCdNi, the nanocrystallization of the surface improves the surface activity of the base metal, promotes the dissolution of the pure titanium base material into the liquid solder, Joint performance improvement is favorable, the joint strength increased by 13.8% than the non-pretreatment. After the soldering temperature exceeds 650 ℃, the high activity of the base nanocrystalline surface layer thickens the intermetallic compound layer in the interfacial region, but the joint performance declines. Due to the difficulty of the elemental solid diffusion at the soldering temperature, The influence of the elements in the matrix on the diffusion of the base metal is not obvious. After the pre-treatment of the base material nanocrystallization, the beneficial properties of the nano-scale can be exerted by reducing the soldering temperature and shortening the holding time during brazing while avoiding the adverse effects.