The Influence of Li on the Fracture Characteristics and Mechanical Properties of Extruded Beryllium-Aluminum...

Alloying is an important method to improve the mechanical properties of beryllium-aluminum composites. In this study, two kinds of beryllium-aluminum composites with and without Li were prepared by pressure impregnation method and extrusion, and the effects of Li on the microstructure and mechanical properties of beryllium-aluminum alloy were investigated by XRD, SEM and tensile test. The results show the addition of Li enhances the absorption of oxygen and nitrogen in the alloy; however, there is no significant change in the material's density, which remains at 2.07 g/cm³. Despite an exacerbation of debonding phenomena at the fracture surface of Li-containing beryllium-aluminum alloys and a decrease in ductile dimples density, the yield strength increased from 266.2 MPa to 317.1 MPa, the tensile strength increased from 348.6 MPa to 411.4 MPa, and the elongation only decreased slightly from 2.9% to 2.5%. These experimental results support the design and preparation of high-performance beryllium-aluminum composites.