The addition of scandium to aluminium limits the grain growth in the heat zone of welded aluminium components.
This has two beneficial effects: the precipitated Al₃Sc forms smaller crystals than in other aluminium alloys, and the volume of precipitate-free zones at the grain boundaries of age-hardening aluminium alloys is reduced.
Both of these effects increase the usefulness of the alloy.
However, titanium alloys, which are similar in lightness and strength, are cheaper and much more widely used.

The alloy Al₂₀Li₂₀Mg₁₀Sc₂₀Ti₃₀ is as strong as titanium, light as aluminium, and hard as ceramic.

The main application of scandium by weight is in aluminium-scandium alloys for minor aerospace industry components.
These alloys contain between 0.1% and 0.5% of scandium.
They were used in the Russian military aircraft, specifically the Mikoyan-Gurevich MiG-21 and MiG-29.

Some items of sports equipment, which rely on high-performance materials, have been made with scandium-aluminium alloys, including baseball bats and bicycle frames and components.
Lacrosse sticks are also made with scandium.
The American firearm manufacturing company Smith & Wesson produces semi-automatic pistols and revolvers with frames of scandium alloy and cylinders of titanium or carbon steel.

Dentists use erbium-chromium-doped yttrium-scandium-gallium garnet (Er,Cr:YSGG) lasers for cavity preparation and in endodontics.

The first scandium-based metal-halide lamps were patented by General Electric and initially made in North America, although they are now produced in all major industrialized countries.
Approximately 20 kg of scandium (as Sc₂O₃) is used annually in the United States for high-intensity discharge lamps.
One type of metal-halide lamp, similar to the mercury-vapor lamp, is made from scandium triiodide and sodium iodide.
This lamp is a white-light source with high color rendering index that sufficiently resembles sunlight to allow good color-reproduction with TV cameras.
About 80 kg of scandium is used in metal-halide lamps/light bulbs globally per year.

The radioactive isotope ⁴⁶Sc is used in oil refineries as a tracing agent.
Scandium triflate is a catalytic Lewis acid used in organic chemistry.
The addition of scandium to aluminium limits the grain growth in the heat zone of welded aluminium components. This has two beneficial effects: the precipitated Al₃Sc forms smaller crystals than in other aluminium alloys, and the volume of precipitate-free zones at the grain boundaries of age-hardening aluminium alloys is reduced. Both of these effects increase the usefulness of the alloy. However, titanium alloys, which are similar in lightness and strength, are cheaper and much more widely used.
The alloy Al₂₀Li₂₀Mg₁₀Sc₂₀Ti₃₀ is as strong as titanium, light as aluminium, and hard as ceramic.
The main application of scandium by weight is in aluminium-scandium alloys for minor aerospace industry components. These alloys contain between 0.1% and 0.5% of scandium. They were used in the Russian military aircraft, specifically the Mikoyan-Gurevich MiG-21 and MiG-29.
Some items of sports equipment, which rely on high-performance materials, have been made with scandium-aluminium alloys, including baseball bats and bicycle frames and components. Lacrosse sticks are also made with scandium. The American firearm manufacturing company Smith & Wesson produces semi-automatic pistols and revolvers with frames of scandium alloy and cylinders of titanium or carbon steel.
Dentists use erbium-chromium-doped yttrium-scandium-gallium garnet (Er,Cr:YSGG) lasers for cavity preparation and in endodontics.
The first scandium-based metal-halide lamps were patented by General Electric and initially made in North America, although they are now produced in all major industrialized countries. Approximately 20 kg of scandium (as Sc₂O₃) is used annually in the United States for high-intensity discharge lamps. One type of metal-halide lamp, similar to the mercury-vapor lamp, is made from scandium triiodide and sodium iodide. This lamp is a white-light source with high color rendering index that sufficiently resembles sunlight to allow good color-reproduction with TV cameras. About 80 kg of scandium is used in metal-halide lamps/light bulbs globally per year.
The radioactive isotope ⁴⁶Sc is used in oil refineries as a tracing agent. Scandium triflate is a catalytic Lewis acid used in organic chemistry.
Scandium