What is meant by master alloy?
A master alloy is a base metal, such as aluminum, copper or nickel, combined with a relatively high percentage of one or two other elements. An example is AlTi10 - a binary alloy consisting of 10% titanium in aluminum. Master alloys are semi-finished products. It is manufactured to be used as a raw material for the metal industry. Master alloys are produced in various shapes. For example: ingots, waffle plates, rods in coils, etc.
Master alloys are used worldwide. They are always present in factories where metals are melted, alloyed with various elements and then cast into shapes. This can be aluminum, iron, steel, or even precious metals like gold.
There are several reasons for adding master alloys to the melt. One of the main applications is composition tuning, i.e. changing the composition of a liquid metal to achieve a desired chemical specification. Another important application is structural control - influencing the microstructure of metals during casting and solidification to alter their properties. These properties include mechanical strength, ductility, electrical conductivity, castability or surface appearance. Master alloys are also sometimes referred to as "hardeners," "grain refiners," or "modifiers," depending on their application.
Reasons for using master alloys instead of pure metals may be economic, technical, or both. When added in pure form, some elements show high losses - or low yields. Others do not dissolve at all at the furnace temperature of the foundry. Master alloys often provide the solution because it dissolves faster at lower temperatures, saving valuable energy and production time.
The master alloy industry uses specialized equipment such as high temperature induction furnaces to produce alloy compositions suitable for conventional metal industry use.