BeO杂质形态与分布对金属铍力学性能的影响

摘要

The effects of the morphology and distribution of BeO impurity on the mechanical properties of metal beryllium in the powder hot isostatic pressed (HIPed) metal beryllium and the vacuum annealed ones were studied, and the general conclusions were obtained. The results show that the morphology and distribution of BeO impurity play more important roles than the BeO content in controlling mechanical properties of beryllium. When BeO particles monodisperse distribution in the beryllium matrix, BeO particle size and interparticle distance along the grain boundaries of Be are key factors to affect the strength and ductility of Be material, and BeO with size larger than 300 nm is the main reason of poor ductility of Be. BeO particles at the triple grain boundary junctions of Be, which is equivalent to the pre-fabricated microcracks inside, mainly lead to poor ductility of Be material.%研究热等静压金属铍材中BeO杂质分布状态和颗粒尺寸对金属铍力学性能的影响,并通过设计真空退火试验,进一步调控BeO杂质在铍基体中的分布,得出BeO杂质形态与分布对力学性能的影响规律.结果表明:相比于BeO含量,BeO杂质的分布和形态对金属铍力学性能的影响更为关键;当BeO粒子弥散分布时,位于晶界上BeO粒子的尺寸及间距是决定金属铍材强度与塑性的关键因素,粗大的BeO粒子(粒径大于300 nm)是导致铍材塑性低的主要原因之一;三叉晶界不致密BeO聚集态相当于在材料内部预制一定尺寸的微裂纹,也是影响铍材伸长率的主要因素.