prealloying

Prealloying is a metallurgical practice in which alloying elements are introduced to a base metal prior to final processing to form a homogeneous material. The term often refers to the preparation of a prealloyed ingot or powder in which the desired composition is achieved by melting and mixing the constituent elements so that their distribution is uniform throughout the material.

Common methods include producing a master alloy by melting the constituent elements and then casting into ingots, billets, or sheets; or producing prealloyed powders by methods such as gas atomization or other powder metallurgy techniques. In steelmaking, prealloying elements such as chromium, nickel, and molybdenum are added to iron to form a consistent composition before further processing. In aluminum and nickel-based systems, prealloyed powders provide homogeneous starting material for extrusion, casting, or additive manufacturing.

Advantages of prealloying include improved chemical homogeneity, predictable microstructure, reduced segregation during solidification, and simplified processing steps in subsequent operations. Prealloyed materials are particularly valuable in powder metallurgy and additive manufacturing where uniform composition is critical.

Limitations include higher cost due to additional processing steps, potential loss of volatile elements during melting, oxidation or contamination, and reduced flexibility to adjust composition on the shop floor. Prealloyed materials are most advantageous when the final product requires tight composition control and uniform properties across components.

See also: master alloy, alloying, powder metallurgy, homogenization.