Fabrication and synthesis of alloy

Jan 13,2023

The metal material with metal characteristics formed by alloying process (melting, mechanical alloying, sintering, vapor deposition, etc.) of two or more metal elements or adding other non-metallic elements based on metal is often called alloy. However, the alloy may contain only one metal element, such as steel. (Steel is a general term for ferroalloys with carbon content between 0.02% and 2.00% by mass)

Here, we need to note that alloys are not mixtures in general concepts, and can even be pure substances, such as single-phase metal intermetallic alloys. The added alloy elements can form solid solutions and compounds, and produce endothermic or exothermic reactions, thus changing the properties of the metal matrix.

The formation of alloy often improves the properties of element elements. For example, the strength of steel is greater than that of its main constituent element iron. The physical properties of the alloy, such as density, reactivity, Young's modulus, conductivity and thermal conductivity, may be similar to the constituent elements of the alloy, but the tensile strength and shear strength of the alloy are usually very different from the properties of the constituent elements. This is due to the great difference in the atomic arrangement between the alloy and the simple substance.

A small amount of certain elements may have a great impact on the properties of the alloy. For example, impurities in ferromagnetic alloys can change the properties of the alloys.

Unlike pure metals, most alloys do not have a fixed melting point. When the temperature is within the melting temperature range, the mixture is solid-liquid coexistence. Therefore, it can be said that the melting point of the alloy is lower than that of the constituent metals. See eutectic mixture. Among the common alloys, brass is an alloy of copper and zinc; Bronze is an alloy of tin and copper, which is used for sculpture, decoration and church bells. Some countries use alloys (such as nickel alloys) for their currencies.