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

对不同取向的单晶B2稀土金属间化合物（YCu, YAg）在296K ~ 4K温度范围内进行了拉伸试验，以明确其变形机理。通过不同温度下的应力松弛实验和应变速率变化实验确定了活化参数。一方面，这为研究第二相（b27结构）对YCu变形机制的影响提供了独特的机会，有助于理解YCu的脆性向韧性转变。另一方面，可以在较大的温度范围内研究YAg的变形机理，并检测可能的变形机理变化。通过比较，得出了这些B2金属间化合物具有高延展性的原因。目的是更好地理解B2稀土金属间化合物的低脆性到延性转变。

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.