传统合金材料学一般认为,合金中加的金属种类越多,脆性化合物越多,这类化合物一旦增加,材料延展性、硬度都会跟着下降,连带缩小使用范围.因此以往的合金中主要的金属成分可能只有一两种.例如,钢铁就是一种以铁为主的铁碳合金,即以铁为基础,再加入一些微量的碳元素来提升其特性.高熵合金(High-Entropy Alloys)简称HEAs,是由五种或五种以上等量或大约等量金属形成的合金.高熵合金却和以往的合金不同,有多种金属却不会脆化,是一种新的材料.

Performances of polycrystalline beryllium and its technological process of production are introduced.Its fracture behaviors at room temperature is also reviewed,which included:fracture characteristics;influence factors of fracture performances such as size and shape of beryllium powders,process of powdered metal compacting,surface residual stress,machine-damage,and impurities(BeO,Fe,Al,Cr,Ag,Si,C,etc)embedded in grains.By authors′opinion the basic researches of beryllium in engineering may be carried out in future is forecasted at the end of the paper.