Indium is often referred to as the "vitamin of alloys." Indium alloys can be used as soldering materials, and indium is a new and important additive for lead-free solders. The global trend towards lead-free soldering is favorable for the application of indium solders. Leveraging the low melting point of indium alloys, special alloys can also be produced for circuit protection devices in fire protection systems and thermal control devices in automatic control systems; bearing alloys made with a small amount of indium have a lifespan 4-5 times longer than conventional bearing alloys. Indium alloys can also be used in dental, steel, and non-ferrous metal corrosion-resistant decorative parts, as well as in metalized plastics.

Due to its strong corrosion resistance and light-reflective properties, indium can be used to make reflectors on warships or cruise ships. Indium is sensitive to neutron radiation and can be used as a monitoring dose material in the atomic energy industry. Currently, the amount of indium used in the atomic energy industry is roughly comparable to its usage in the electronics industry.

Indium can act as an additive in lead-acid batteries, a corrosion inhibitor in mercury-free alkaline batteries, making the batteries environmentally friendly. The use of indium in preventing fuming continues to increase, with initial coatings adopted in the automotive industry, potentially extending to industrial and residential construction. Sony Corporation of Japan has invented a new cathode using indium instead of scandium, reducing the cost of each electron to about one-tenth of that of scandium-coated electrons. Therefore, indium's application in high-power television output and long-life performance is promising.

In the optoelectronics field, indium and its compound semiconductors have a wide range of applications. Among the III-V族 compound semiconductors based on indium, such as indium antimonide (InSb), indium phosphide (InP), and indium arsenide (InAs), indium antimonide (InSb) was the earliest to be researched and applied. Indium phosphide (InP), however, is gaining attention and holds promising potential applications. It has made breakthroughs in microwave to millimeter-wave communication, as a laser source for fiber-optic communication, and as a material for heterojunction solar cells, showcasing the favorable prospects of indium applications. Indium antimonide and indium arsenide are also crucial in infrared detection and photomagnetic devices. In solar cells, indium compound thin films are emerging as a new force, attracting attention for their high conversion rates, low cost, and portability. Copper indium selenide (CIS) and other I-II-VI ternary compound thin film semiconductor materials, with their low cost, good performance, and simple processing, will become a significant direction for the development of the solar cell industry in the future, driving the increased use of indium in this field. The new industry centered around information technology has emerged, with indium tin oxide (ITO) being an indispensable key material for various flat-panel displays. Currently, about 75% of the world's indium is consumed in this area, with great potential for the future. Moreover, as the extraction and processing technologies of indium continue to advance and production costs decrease, the applications of indium are expanding further.

Indium is a silver-gray, extremely soft, fusible metal. Melting point: 156.61°C. Boiling point: 2060°C. Relative density: d7.30. Liquid indium wets glass and adheres to surfaces it contacts, leaving black stains.

Indium has slight radioactivity. There are two main isotopes of indium, one being In-113, a stable isotope, and In-115 undergoing beta decay. Therefore, it is best to avoid direct contact as much as possible during use.

Ingot indium, due to its strong light penetration and conductivity, is mainly used in the production of ITO targets (used for manufacturing LCDs and flat panel screens), which is the primary consumption field for indium, accounting for 70% of the total indium consumption.

The following consumer sectors are: the electronics semiconductor field, accounting for 12% of consumption; the solder and alloy sector, taking up 12%; and the research industry, accounting for 6%. Additionally, due to its soft nature, it is also used for filling gaps in industries requiring metal filling, such as vacuum gap filling materials at higher temperatures.

Medically, indium colloid is used for liver, spleen, and bone marrow scans. Indium-DTPA is used for brain and kidney scans. Lung scans utilize indium-Fe(OH)3 particles. Placental scans employ indium-Fe-ascorbic acid. Liver blood pool scans are conducted with indium-bound transferrin.

Gallium and indium alloy compositeLiquid MetalThe material forms a solid solution alloy that becomes liquid at room temperature with a surface tension of 500 millinewtons per meter. This means that, without external force, when placed on a flat surface, the alloy maintains an almost perfect spherical shape. Upon the application of a small electrical current, the surface tension of the sphere decreases, and the metal spreads out on the surface. If the charge changes from negative to positive, the liquid metal reverts to a spherical shape. Adjusting the voltage can also modify the surface tension and viscosity of the metal, allowing it to take on different structures. This research can also be used to help repair severed human nerves, preventing long-term disability. Researchers claim that this breakthrough aids in the construction of circuits and self-healing structures.