Rolled vs Forged Copper Alloy Plates for C18000, C18150, C18200

Created at : Mar 10, 2023

Copper Alloy Plates are typically produced by passing cast copper alloy billets between large steel rollers, aka, rolling mill(s) until the required thickness is attained. This process can be performed hot or cold, or a combination of hot and cold depending on the final thickness, with thinner sections below 2" typically finished via cold rolling. 

Rolled Plate: copper alloy plates are typically produced by passing cast copper alloy billets between large steel rollers until the required thickness is attained. It is then solution annealed and precipitation hardened.

Cadi Company carries 1/8” to 6” thick plates.

Copper Alloy Plates that finish thicker than 2" may also be produced directly by hot forging (open die forging). 

Characteristics of Cold Rolled Plates: 

• Cold rolling work hardens the material by elongating the microstructure(grains) inducing internal stress within the material.
• When cold rolled plates are machined, plates often warp (bend) as a result of non-uniform removal of variable stressed material at the surface of the strip. Often these require stress relief heat treating that may reduce surface tensile stresses, and therefore warping.
• Grain structure of rolled plates is typical of cold worked material with elongated grains with many grain boundaries destroyed.
• Cold rolled plates will have higher hardness and tensile strength when compared to forged plates.

Forged Plate: copper alloy plates are produced by the copper billet being pressed down to the desired thickness. It is then solution annealed and precipitation hardened.

Cadi Company carries 1/8” to 12” thick plates.

Cadi Company utilizes a unique process that allows thinner plates to be supplied as rolled or forged plates that may be some advantages sourcing forged plates rather than rolled plates. 

Characteristics of Forged Plates: 

• Forging is performed at elevated temperatures where the metal may recrystallize during forging, or the grain structure will flow easily with the direction of forging.
• Forging is normally performed in multiple stages allowing the material to be worked in three normal planes – often referred to as cross grain forging.
• Forged plates are typically machined to a rough oversize dimension to remove surface oxide formed during hot forging
• Forged plates do not exhibit surface stresses, allowing it to be machined with little or no internal stress condition, common with rolled plate, i.e., they don’t warp.

C18000, C18150, and C18200 are heat treatable copper alloys, hardened by heat treating so cold working (rolling) is not required to yield increased strength and hardness when compared to regular copper (ETP, and OF) that require cold rolling to attain higher hardness.