Investigations on deformation mechanism of monocrystalline B2 rare-earth intermetallic compounds at low temperatures

在296K-4K温度范围内，对不同取向的单晶B2稀土金属间化合物(YCu，YAG)进行了拉伸试验，以确定其变形机制。通过应力松弛实验和应变速率变化实验确定了不同温度下的激活参数。一方面，研究第二相(B27-结构)对变形机制的影响是一个难得的机会，有助于理解YCu的脆韧转变。另一方面，可以在较大的温度范围内研究YAG的变形机制，并可以检测到可能的机制变化。通过比较，可以得出这些B2金属间化合物延展性极高的原因。其目标是更好地理解B2稀土金属间化合物的低脆-韧性转变。

Tensile test are performed on monocrystalline B2 rare-earth intermetallic compounds (YCu, YAg) of different orientations in the temperature range between 296K and 4K in order to specify the deformation mechanism. Activation parameters are determined by means of stress relaxation experiments and strain-rate-change experiments at several temperatures. On the one hand there is the unique opportunity to study the influence of a second phase (B27-structure) on the deformation mechanism to contribute to the understanding of the brittle-to-ductile transition of YCu. On the other hand the deformation mechanism of YAg can be investigated in a large temperature range and possible changes of mechanism can be detected. By comparing conclusions about the causes of exceptionally high ductility of these B2 intermetallic compounds can be drawn. The goal is a better understanding of the low brittle-to-ductile transition of B2 rare-earth intermetallic compounds.