An alloy is a mixture of two or more metals fused together in molten state. Metals when melted tend to dissolve in one another forming alloys. The various properties of a metal like malleability, ductility, strength, hardness, resistance to corrosion and appearance can be improved by mixing with other metals. Alloys have properties different from its constituents.
Preparation of Alloys
There are four commonly employed methods for the manufacture of alloys: the fusion method, the electro-deposition method, the reduction method, and powder metallurgy.
The Fusion Method
This method uses alloying elements in a fixed proportion and fuses them together in a refractory melting pot or in a brick-lined crucible. The component metal with a higher melting point is melted first and then the other component with a lower melting point is added to the melt. Both metal components are mixed well and allowed to melt further. The molten mass is covered by powdered Carbon to avoid oxidation of the molten alloy components because they are very reactive to the surrounding atmospheric oxygen. The resulting molten mass is allowed to cool at room temperature.
The Electro-Deposition Method
This method involves simultaneous deposition of different component metals from the electrolytic solution containing their salts solution mixture by passing direct electricity.
The Reduction Method
Metal may exist in the form of compounds. Reduction is a chemical process in which a compound of one component can be separated from another component, to get a pure metal. This method is performed in an electric furnace.
Note In all the methods used to prepare alloys, Carbon, salts, and oxides are residuals that may hinder the properties of the produced alloy, which is generally contaminated.
Powder Metallurgy
Powder metallurgy may be defined as the art of producing fine metal powders and then making articles from individual metal powders or alloyed metal powders with or...
