Abstract:

Be and CuCrZr alloys for ITER first wall are connected by the thermal isostatic pressure diffusion
bonding technique, and partial connectors that completed the diffusion connection are annealed. Using ultrasonic
nondestructive testing of all connectors, defects in the Be-Cu connection interface of unannealed connector are
observed. In order to analyze the cause of the defect in the diffusion interface, a sample from the defect zone of
the connector was selected and analyzed with the interface microanalysis. By observing the micromorphology and
analyzing the change of alloying elements in the diffusion layer of the interface, it was found that the thickness of
the Cu-Ti diffusion layer and the thickness of the Ti layer in the Be-Cu diffusion interface after annealing were
increased. The probability of the formation of the brittle phase between the Be and the Cu elements in the middle
layer was reduced. The thickness of the whole diffusion layer became larger and the range of diffusion was larger.
The experimental results show that the annealing process can change the structure of Be-Cu thermal isostatic
pressure diffusion layer and expand the range of diffusion bonding.

Key words: Thermal isostatic pressure diffusion bonding, Ultrasonic test, Be-Cu interface, Diffusion layer; Annealing

摘要：

在ITER第一壁实验件的研究中，采用热等静压扩散连接技术对Be与CuCrZr合金进行连接实验，对完成扩散连接的部分连接件采用退火处理。对所有连接件进行超声波无损探伤后，检测到未退火的连接件Be/Cu连接界面存在缺陷。为分析扩散界面缺陷产生原因，从连接件的无缺陷区取样并进行界面微观分析。通过观察微观形貌和分析界面扩散层合金元素的变化，发现退火处理过的Be-Cu扩散界面的Cu-Ti扩散层和未扩散的Ti层厚度增加，中间层中Be与Cu元素形成脆性相的几率降低，整个扩散层厚度变大，扩散范围加大。实验表明退火工艺能改变Be/Cu热等静压扩散层连接结构组成，扩大扩散连接范围。

关键词: 热等静压扩散连接, 超声波检测, Be-Cu界面, 扩散层, 退火