Be-Al alloy is a type of in situ metal matrix composite composed of a primary Be phase for strength and stiffness and a continuous Al matrix for ductility and toughness. Be-Al alloy (AlBe-Cast^®910) has the characteristics of low density (2.17 g/cm³), high elastic modulus (193 GPa) and specific stiffness (88.94 GPa/(g/cm³)) as a preferred material for lightweight aerospace products. Investment casting technology can be employed to prepare the components with thin-walled complex structures for aerospace; however, the wide solidification range for Be-Al leads to difficulty in feeding a casting and results in extensive shrinkage and porosity in cast parts. In this paper, the characteristics of Be-Al alloy are introduced first. Secondly, the mechanisms of influence of adding elements on the casting process, mechanical properties (strength increases more than 20% by adding elements) and microstructure evolution are explained in detail. In addition, the heat treatment technology (strength increases at least 10% after heat treatment) and the repair of defects by electron beam welding are discussed. Finally, Be-Al alloy is a new type of composite material, and China is a major research and application country; this paper introduces its research status and analyzes existing problems and shortcomings and points out the direction of Be-Al alloy development in China in the next few years.

This study examines the microstructural evolution and tensile response of a cold-rolled C17200 Cu–Be–Co alloy strip after short-time annealing at 550 and 610 °C. X-ray diffraction (XRD), electron backscatter diffraction (EBSD), kernel average misorientation (KAM) analysis, transmission electron microscopy (TEM), and room-temperature tensile testing were used to compare phase constitution, grain-boundary character, recrystallization behavior, texture evolution, dislocation substructure, and tensile properties. The results show that both annealed samples mainly consisted of an α-Cu matrix and a small amount of BeCu-related precipitates. After annealing at 550 °C, the alloy retained a recovery-dominated partially recrystallized microstructure, with an average grain size of 1.47 μm, a low-angle grain boundary fraction of 8.4%, a recrystallized fraction of 18.06%, and evident residual dislocation substructures. This condition exhibited a yield strength of 365.5 MPa. After annealing at 610 °C, recrystallization was substantially promoted, the average grain size increased to 1.92 μm, the high-angle grain boundary fraction increased to 97.5%, and the recrystallized fraction reached 82.76%. Meanwhile, the yield strength decreased to 276.6 MPa because of the reduced contribution from dislocation strengthening. These results indicate that, under the two investigated short-time annealing conditions, the strength difference in the alloy is mainly associated with the transition of microstructural evolution from recovery-dominated partial recrystallization to a recrystallization-dominated microstructure.