Stability of microstructure and its evolution during solid-state annealing of Al2O3―Inconel 600 brazed couples
Stability of microstructure and its evolution during solid-state annealing of Al2O3―Inconel 600 brazed couples
复制标题
DOI：
10.1016/j.actamat.2011.04.041
复制
发表时间：
2011-08
期刊：
影响因子：
9.4
通讯作者：
A. Laik;P. Mishra;K. Bhanumurthy;G. Kale;B. Kashyap
中科院分区：
文献类型：
--
作者：
A. Laik;P. Mishra;K. Bhanumurthy;G. Kale;B. Kashyap
在模拟使用条件下，通过对铝-因康耐尔600钎焊接头进行400℃和560℃的长时间热处理，研究了钎焊接头组织的稳定性。通过对钎焊区组成相的广泛显微分析，研究了钎焊区组织和显微化学的演变。在560℃热处理后，钎焊区的层状组织转变为均匀的、接近平衡的两相组织，固体相互扩散被认为是导致这种组织大量改变的主要因素。400℃中温热处理表明，微观组织的转变机制是Ni覆盖层的球状化和Mo从金属化层向富Ni相的溶解。分析了每种元素在热处理过程中的迁移行为。铬从铬镍铁合金中扩散出来，在铝-钎焊合金界面处形成一层cr2o3。界面的结合强度高到足以导致接头氧化铝侧的内聚破坏。
The stability of the microstructure of alumina–Inconel 600 brazed joints was investigated under simulated in-service conditions by subjecting them to prolonged heat treatment at 400 and 560° C. The evolution of the microstructure and microchemistry of the brazing zone was examined using extensive microanalysis of the constituent phases. The layered structure of the brazing zone transformed to homogeneous, near-equilibrium, two-phase microstructure after heat treatment at 560° C. Solid-state interdiffusion was identified as a primary factor responsible for such copious modification of the microstructure. Intermediate temperature heat treatment at 400° C revealed that the mechanism of transformation of the microstructure was globulization of the Ni overlayer and dissolution of Mo from the metallization layer into the Ni-rich phase. The migration behavior of each of the elements, in response to heat treatment, was analyzed. Cr was found to diffuse out of Inconel and form a layer of Cr 2 O 3 at the alumina–brazing alloy interface. The bond strength of the interface was high enough to cause cohesive failure in the alumina side of the joints.