According to the number of elements that make up the alloy, there are binary alloy, ternary alloy and multicomponent alloy; According to the different alloy structures, it can be divided into the following three basic types:
(1)*** molten mixture. When the molten mixture solidifies, the components crystallize separately, such as bismuth cadmium alloy. The lowest melting temperature of Bi-Cd alloy is 413 K. At this temperature, the Bi-Cd melt mixture contains 40% Cd and 60% Bi.
(2) solid solution. These components form a solid solution alloy. Solid solution refers to a metal crystal in which solute atoms dissolve into the solvent lattice while still maintaining the solvent lattice type. Some solid solution alloys are formed by replacing some solvent atoms with solute atoms at the lattice nodes of solvent metals, such as alloys of copper and gold; Some solid solution alloys are formed by solute atoms distributed in the lattice gaps of solvents.
(3) Intermetallic compounds. Each component forms an alloy of compounds with each other.
Generally speaking, the melting point of an alloy is lower than that of any of its constituent metals. For example, Wude alloy used as a power fuse has a melting point of only 67℃, which is lower than the four metals that make it up. The hardness of an alloy is usually greater than that of its constituent metals. For example, bronze is harder than copper and tin, and pig iron is harder than pure iron. The electrical conductivity and thermal conductivity of alloy are worse than that of pure metal. Some alloys also have great changes in chemical properties. For example, iron rusts easily. If 15% chromium and 0.5% nickel are added to ordinary steel, it will become an acid-base corrosion-resistant stainless steel.
"Qi" also means alloy. Alloys containing mercury are usually called amalgam. For example, sodium amalgam is an alloy of sodium and mercury, and zinc amalgam is an alloy of zinc and mercury.