Under neutron irradiation, radiation enhanced beta-Nb nano-precipitates develop within the α-grains of the Zr-Nb alloys. This radiation enhanced precipitation is of great interest since it may have some influence on the post-irradiation mechanical behavior of the material. In this paper the shape, the orientation relationship and the interface structure of such nano-particles are studied by means of both conventional and high-resolution transmission electron microscopy. The radiation damage was annealed out, thanks to a prior heat treatment and a creep test, in order to easily observe the beta-Nb nano-particles. The nano-particles exhibit a needle-like shape with a short thickness along the c-direction of 1.5 nm on average, a length and a width respectively of 6 nm and 3 nm, on average, in the basal plane. Using high-resolution TEM, a near Pitsch-Schrader orientation relationship is identified for a nano-particle. The interface atomic structure at various locations around the nano-particle has been accurately determined and an atomic model of the interface structure has been proposed.

在中子辐照下，辐射增强的β-Nb纳米沉淀物在Zr-Nb合金的α晶粒内形成。这种辐射增强的沉淀引起极大的兴趣，因为它可能对材料的辐射后机械性能产生某些影响。本文通过常规和高分辨率透射电子显微镜研究了这种纳米粒子的形状，取向关系和界面结构。由于事先进行了热处理和蠕变试验，辐射损伤被退火，以便于观察β-Nb纳米颗粒。纳米颗粒呈针状形状，其沿c方向的短厚度平均为1.5nm，在基面上的长度和宽度分别平均为6nm和3nm。使用高分辨率TEM，对于纳米颗粒，确定了接近的Pitsch-Schrader取向关系。已经精确确定了纳米粒子周围各个位置的界面原子结构，并提出了界面结构的原子模型。