- The principal properties of beryllium are its low density, high strength, high rigidity, reflectivity, structural stability at high temperatures and conductivity of heat. Beryllium is notable among metals in terms of specific rigidity; i.e. the ratio of modulus to density.
- The rigidity of beryllium, usually expressed as it modulus, is about 50% greater than that of steel, while its density (1.84 g/cm³) is about 30% less than that of aluminium. The specific rigidity of beryllium is around six times greater than that of any other metal or alloy, and four times that of composites.
- Beryllium metal is used to produce discrete components used within certain specialized, high technology equipment, where it remains environmentally inert throughout its useful life. Weight is a controlling factor when launching vehicles into space, and lightweight structures are vital. At the same time, however, it is imperative that such structures are rigid, and not subject to distortions or resonant vibrations which might reduce the accuracy of their instrumentation. Beryllium metal is the optimal material for these purposes, principally because of its high specific rigidity. It also has attractive thermal properties which reduce thermal distortions, both at the high temperatures experienced during launch and descent, and also at the sub-zero temperatures of space.
- It is an isotropic material, meaning it has uniform properties in all directions, which increases freedom of design. Its formability, machinability and joinability allow relative ease of manufacture of complex structures. No other material offers this useful combination of properties. The isotropy and thermal properties of beryllium serve to minimise distortions in sophisticated dimensional applications. Beryllium can be machined to form complex curved surfaces, its ability to be highly polished and its ability to accept coatings for enhanced reflectivity at various wavelengths. So too, the structural components made of beryllium offer comparable advantages in combination with the optical components.
- Beryllium remains stable at high temperatures (melting point 1284ºC) and can be used as a heat sink.
- Another special property of the metal is that it is highly transparent to X-rays. In foil form, beryllium is used as the window material for X-ray sources and detectors. It is especially useful in security devices and high-resolution medical imaging technology, such as mammography to detect breast cancer.
- It is the material of choice for the fail-safe final wall lining relied upon to control the high temperature gas plasma of experimental fusion energy reactors. Beryllium is a very efficient moderator of neutrons, slowing and reflecting them, a property that finds application in materials test reactors and in fundamental particle physics research, including efforts to develop clean alternative energy sources, such as the International ITER fusion reactor, now under construction in Europe. It is an extremely useful alloying element, conferring high strength even when added in relatively small proportions to high conductivity alloys, particularly copper-based alloys.
- In solid form, as it is normally supplied and used, the metal is stable and inert. It is neither radioactive, nor water soluble. It is corrosion resistant in normal ambient conditions; it is resistant to high temperatures; and it does not give off emissions under the normal range of environmental conditions. It may be handled and stored without special precautions.
- Beryllium metal and composites are used as discrete components within certain specialised, high technology equipment where it remains environmentally inert throughout its useful life. Broadly, the applications for the metal and composites are represented by the categories listed below.