Classification and uses of nonferrous metals
There are only more than 80 kinds of non-ferrous metal elements, but there are many kinds of non-ferrous alloys with different properties. The strength and hardness of non-ferrous alloys are generally higher than that of pure metals, their resistance is greater than that of pure metals, their temperature coefficient of resistance is smaller, and they have good comprehensive mechanical properties. Commonly used non-ferrous alloys include aluminum alloy, copper alloy, magnesium alloy, nickel alloy, tin alloy, tantalum alloy, titanium alloy, zinc alloy, molybdenum alloy, zirconium alloy, etc.
Uses:
A: Copper among non-ferrous metals is one of the earliest metal materials used by humans. In modern times, nonferrous metals and their alloys have become indispensable structural and functional materials in machinery manufacturing, construction, electronics industry, aerospace, nuclear energy utilization and other fields.
B: In practical applications, non-ferrous metals are usually divided into 5 categories:
1. Light metal. The density is less than 4500 kg/cubic meter, such as aluminum, magnesium, potassium, sodium, calcium, strontium, barium, etc.
2. Heavy metals. Density greater than 4500 kg/m3, such as copper, nickel, cobalt, lead, zinc, tin, antimony, bismuth, cadmium, mercury, etc.
3. Precious metals. It is more expensive than commonly used metals, has low abundance in the earth's crust, and is difficult to purify, such as gold, silver and platinum group metals.
4. Semi-metal. The nature and value are between metals and non-metals, such as silicon, selenium, tellurium, arsenic, boron, etc.
5. Rare metals. Including rare light metals, such as lithium, rubidium, cesium, etc.;
Rare refractory metals, such as titanium, zirconium, molybdenum, tungsten, etc.;
Rare dispersed metals, such as gallium, indium, germanium, thallium, etc.;
Rare earth metals, such as scandium, yttrium, and lanthanide series metals;
Radioactive metals, such as radium, francium, polonium and uranium and thorium in the Al series elements.
