Analytical Electron Microscope Study of Low Temperature Diffusion Couples

微结构特征、晶体学方向关系和组合变体在扩散耦合器绑定的低退火温度被分析电子显微镜（AEM）中的微结构特征、晶体学方向关系和组合变体。表面激活绑定（SAB）方法被用作制造扩散耦合器的一种技术。样本的表面是在扩散键上分离的离子束之前，在按顺序清除氧化物层或在绑定接口上进行污染。In the Ni/Ni·D23·D2A1 diffusion couples prepared by the SAB method， the Ni-rich solid solid phase （\） grows towards the Ni·D23·D2Al-based intermetallic phase （\） during diffusion annealed。γ/γ'接口是由SAB方法准备的对耦合中的平坦和平行连接的接口。您的位置：知道173> On the other hand， the？and？phases in the Ni/Ni？D23？D2A1 diffusion couple prepared without sputtering and diffusion annealed at 1123 K has a different crystallogManagement orientation。这是很清楚的，因为分离的绑定接口对扩散耦合中的相位的增长过程有很大的影响。精细颗粒铝合金是由平等通道角压（ECAP）技术处理的，颗粒边界扩散是通过SAB方法制备的扩散耦合器进行测试的。在精细颗粒的扩散偶对中的干扰作用明显大于颗粒偶在低退火温度下的颗粒偶中的干扰作用。细粒度扩散对中扩散的激活能量被估计约有两个，其中一个在细粒度扩散对中。这是很清楚的，因为SAB方法是非常有用的，可以在低绑定温度和允许通过分析电子显微镜研究低温度干扰过程。

The microstructrual features, crystallographic orientation relationships and compositional variations across the interface in diffusion couples bonded at low annealing temperatures were investigated by analytical electron microscopy (AEM). The surface activated bonding (SAB) method was used as a technique to produce the diffusion couples. The surface of the sample was ion-beam sputtered before diffusion bonding in order to clear-off the oxide layer or contamination at the bonded interface. In the Ni/NiィイD23ィエD2A1 diffusion couples prepared by the SAB method, the Ni-rich solid solution phase (γ) grows towards the NiィイD23ィエD2Al-based intermetallic phase (γ') during diffusion annealed. The γ/γ' interphase interface is flat and parallel to the bonded interface in the couples prepared by the SAB method. The γ and γ phases in the Ni/NiィイD23ィエD2A1 diffusion couple annealing at 1123K has the same crystallographic orientation. On the other hand, the γ and γ phases in the Ni/NiィイD23ィエD2A1 diffusion couple prepared without sputtering and diffusion annealed at 1123K has a different crystallographic orientation. It is clear that the sputtering of bonding interface has a large effect on the growth process of phases in the diffusion couples. Fine-grained aluminum alloys were processed by the equal-channel angular pressing (ECAP) technique and the grain boundary diffusion was examined using the diffusion couples prepared by the SAB method. The interdiffusion coefficients in the fine-grained diffusion couples are significantly larger than those in coarse-grained couples particularly at lower annealing temperatures. The activation energy of diffusion in the fine-grained diffusion couple was estimated to be about two third of that in the coarse-grained one. It is clear that the SAB method is very useful to prepare the diffusion couples at lower bonding temperatures and enables to study the low temperature interdiffusion process by analytical electron microscopy.