Concepts of Metallic Materials

1. Metals

Metals are substances that are shiny, have good electrical and thermal conductivity and good mechanical properties, and have a positive temperature coefficient of resistance. Can be divided into two categories: ferrous metals and non-ferrous metals.

Ferrous metals mainly refer to iron, manganese, chromium elements and their alloys such as steel, pig iron, ferroalloys and so on.

Non-ferrous metals mainly refers to metal elements other than ferrous metals (a total of 79 kinds) and their alloys. Pure non-ferrous metals can be divided into light non-ferrous metals, heavy non-ferrous metals, precious metals and rare metals.

2,Alloy

Alloy is by two or more metal elements, or metal and non-metallic elements together with the metal properties of the substance.

3,Light non-ferrous metals

Light non-ferrous metals refers to the specific gravity of 4.5 or less non-ferrous metals, they are: aluminum, magnesium, sodium, potassium, calcium, strontium, barium, the common characteristics of its specific gravity is small (0.53-4.5), chemical activity.

4, heavy non-ferrous metals

Heavy non-ferrous metals refers to the specific gravity of 4.5 or more non-ferrous metals, including copper, nickel, lead, zinc, cobalt, tin, antimony, mercury, cadmium, bismuth and so on.

5,Precious metals

Precious metals refers to gold, silver and platinum group elements. Precious metals are characterized by the specific gravity (10.4-22.4), high melting point (916-3000 ℃), stable chemical properties, acid, alkali, difficult to corrode.

6, semi-metal

Semi-metal refers to silicon, germanium, selenium, tellurium, arsenic, boron and other 9 elements. Its physical and chemical properties between metal and non-metal.

7, rare light metals

Rare light metals refers to lithium, beryllium, rubidium, cesium, titanium five metals. Their common point is that the specific gravity is small.

8,Rare high melting point metals

Rare high melting point metals refers to tungsten, molybdenum, tantalum, niobium, zirconium, hafnium, vanadium and rhenium 8 metals. Their common point is the high melting point, hardness, corrosion resistance, and some non-metals can be generated with very hard and very refractory stable compounds.

9, rare dispersed metals

Rare dispersed metals, also known as rare metals, they are gallium, indium, thallium, germanium four metals.
10, rare earth metals

Rare earth metals include lanthanides and scandium and yttrium, which are very similar in nature to the lanthanides, and a total of 17 metals: scandium, yttrium, lanthanides, cerium, praseodymium, niobium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium and lutetium.

11,Rare radioactive metals

Rare radioactive metals refers to natural radioactive elements, polonium, radium, actinium, thorium, protactinium, uranium.