Wrought phosphor bronzes

Dr. Dmitri Kopeliovich

According to the Unified Numbering System (UNS):

Phosphor Bronzes are copper alloys, containing 1-13% of tin (Sn) and up to 0.3% of phosphorous (P) as the major alloying elements. Wrought Phosphor Bronzes (1.25% E, 5% A, 8% C, 10% D) are designated with the numbers from C50000 through C54999 (including lead phosphor bronzes).

Lead Phosphor Bronzes contain tin (Sn) and phosphorous (P) as the major alloying elements and up to 4% of lead (Pb) as additional alloying element. Wrought lead phosphor bronzes are designated with the numbers from C53000 through C54999.

Phosphor Bronzes containing up to 13% of tin have mono-phase structure (α-phase).

Such alloys have excellent formability in cold state and good corrosion resistance.

Phosphorous is added to the phosphor bronzes as deoxidizing agent during melting; however it also improves mechanical properties of the alloys.

Alloys, containing more than 13% of tin, have significant amount of brittle δ-phase.

These bronzes have very low formability and can not be used as wrought alloys.

Wrought Phosphor Bronzes are strengthened by cold work (strain hardening). Ductility of the alloys decreases as a result of cold work.

Wrought Phosphor Bronzes are used for manufacturing sleeve bushings, springs, clutch discs, fittings, wear resistant parts, electrical contacts, sliding bearings, screw products, valve parts, pressure vessels, pump body castings, impellers for chemical plants.

UNS Designation	Trade mark	Sn,%	Pb,%	P,%	Zn,%	Cu,%
C50500	Phosphor Bronze 1.25% E	1.0-1.7	0.05 max.	0.03-0.35	0.30 max.	balance
C51000	Phosphor Bronze 5% A	4.2-5.8	0.05 max.	0.03-0.35	0.30 max.	balance
C52100	Phosphor Bronze 8% C	7.0-9.0	0.05 max.	0.03-0.35	0.20 max.	balance
C52400	Phosphor Bronze 10% D	9.0-11.0	0.05 max.	0.03-0.35	0.20 max.	balance
C54400	Lead Phosphor Bronze B-2	3.5-4.5	3.5-4.5	0.01-0.50	1.5-4.5	balance

(Materials Data)

• Wrought copper alloy C50500 (Phosphor Bronze 1.25% E)
• Wrought copper alloy C51000 (Phosphor Bronze 5% A)
• Wrought copper alloy C52100 (Phosphor Bronze 8% C)
• Wrought copper alloy C52400 (Phosphor Bronze 10% D)
• Wrought copper alloy C54400 (Lead Phosphor Bronze B-2)

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• Wrought Coppers and high copper alloys
• Wrought brasses
• Wrought aluminum bronzes
• Wrought silicon bronzes
• Wrought copper-nickel alloys and Nickel Silvers
• Spinodal Bronzes
• Cast tin bronzes and leaded tin bronzes
• Classification of copper alloys
• Temper designation of copper alloys
• Treatment of molten copper alloys

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