C5191 Phosphor Bronze Alloy

C5191 phosphor bronze is an alloy composed of copper, tin, and phosphorus, and is a combination of casting and forging. Its outstanding characteristics lie in excellent fatigue resistance and wear resistance, as well as good elasticity. Under normal circumstances, C5191 phosphor bronze exhibits high tensile strength and yield strength, allowing it to maintain good hardness and deformation resistance under various loads. In addition, the alloy performs well in high temperature and humid environments, effectively resisting the erosion of oxidation and other corrosive media.

 

 

 

• JIS (Japanese Industrial Standards): C5191
• ASTM (American Society for Testing and Materials): B139, B159
• EN (European Norms): CW452K (equivalent)

Alloy Designation
GB	UNS	EN	JIS
QSn6.5-0.1	C51900	CuSn6	C5191

 

In terms of chemical composition, the copper content of C5191 phosphor copper is usually above 94%, while the phosphorus content is controlled within a certain range to ensure the stability of alloy properties. In addition, it may also contain trace amounts of elements such as iron and zinc, which have a certain impact on certain specific properties of the alloy.

• Copper: The copper content of C5191 alloy is as high as 96-98%, which is the main alloying element.
• Tin: with a content of about 0.1-0.4%, it is one of the added alloying elements.
• Phosphorus: with a content of about 0.03-0.35%, it is one of the added alloying elements

 

 

From the perspective of mechanical properties, the tensile strength of C5191 phosphor bronze can reach over 600MPa, the yield strength is around 300MPa, and the elongation rate can reach over 15%. These indicators ensure its reliability in many industrial applications. In addition, the alloy hardly experiences brittle fracture during use, greatly improving its service life and stability

 

• Tensile strength: usually between 310-450 MPa, depending on the specific processing state and manufacturing process.
• Yield strength: typically between 110-290 MPa, depending on the specific processing state and manufacturing process.
• Elongation rate: usually between 15-35%, depending on the specific processing state and manufacturing process.
• Hardness:The hardness of C5191 phosphor bronze is usually between 100-170 HB (Brinell hardness), depending on the specific processing state and manufacturing process

 

C5191 is made through multiple processes such as melting casting hot rolling cold rolling annealing. The key is to precisely control the tin phosphorus ratio and strengthen the performance through cold processing. Some high-end applications require vacuum melting to reduce impurities, and subsequent surface treatments (such as passivation) can further enhance corrosion resistance The process characteristics are as follows:

• Accurately control the tin phosphorus ratio to avoid segregation
• Special annealing process stabilizes the grain size at 15-25 μ m
• Surface finishing technology achieves mirror effect with Ra ≤ 0.2 μ m

At room temperature, its elongation is usually between 8% -12%, which means that a 10 centimeter long material will only break when stretched to 10.8-11.2 centimeters. This characteristic makes it an ideal choice for manufacturing parts that require small deformations, such as springs and contact plates.

 

The elongation of C5191 is not fixed, and for every 1% increase in zinc content, the elongation decreases by about 0.5%. When the zinc content increases from 35% to 39%, the elongation will decrease from 12% to 8%. But when the zinc content is below 34%, the material will become too soft and lose elasticity.

 

The addition of phosphorus is more interesting: 0.1% phosphorus can increase the elongation by 1-2 percentage points, but when it exceeds 0.3%, the material becomes prone to fracture. This precise composition control allows C5191 to maintain its strength while possessing ideal elongation performance.

Practical methods to improve elongation:

• Annealing treatment: Heat the material to 600-650 ℃ for 1 hour and then slowly cool it down, which can increase the elongation by 3-5 percentage points. It's like doing SPA on metal, eliminating internal stress and making it more relaxed.
• Cold processing control: The deformation of each cold drawing should not exceed 20%, and it should be carried out multiple times to avoid excessive hardening of the material. Just like kneading dough slowly, if you knead it too hard at once, it will break the gluten.
• Impurity control: Keeping the iron content below 0.05% and the sulfur content below 0.01% can stabilize the elongation rate within the ideal range. Impurities are like sand in dough, which can disrupt the uniformity of the material.

 

Advantage

• Good mechanical properties: It has high strength, elasticity, wear resistance, and diamagnetism, and has good pressure processability in both hot and cold states. Its tensile strength (σ b/MPa) is ≥ 315, elongation (δ 10/%) is ≥ 40 (strip thickness ≥ 0.15). In addition, it also has high fatigue strength, which can be further improved in strength and hardness through heat treatment or cold processing.
• Excellent processing performance: It has high flame resistance to electric discharge, can be welded and brazed, has good machinability, excellent mechanical processing performance and chip forming performance, and can quickly shorten the processing time of parts.
• Strong corrosion resistance: It has good corrosion resistance in the atmosphere, fresh water, and seawater, especially strong resistance to seawater corrosion.
• Good conductivity: It is a good conductive material with a conductivity of 18% IACS.

Shortcoming
Due to its high phosphorus content, it has thermal brittleness during hot processing and can only accept cold pressure processing, while increasing the anti segregation of the ingot.

 

 

 

C5191 phosphor bronze has been widely used in multiple industries due to its unique performance characteristics. Here are some of the main application areas:

• Electronic products: Due to its excellent conductivity, C5191 phosphor bronze is commonly used in the manufacture of electronic components, connectors, cable joints, etc.
• Mechanical manufacturing: Its presence can be seen in mechanical components such as springs, gears, and other parts that withstand high frequencies.
• Automation equipment: In the field of automation, C5191 phosphor bronze is used to manufacture contactors and relays, which can effectively improve the durability and stability of equipment.
• Electrical industry: widely used in the manufacturing of motors, generators, and other electrical equipment, providing good electrical connections and heat dissipation performance.

 

Q1: Is C5191 suitable for acidic environments?

A: C5191 is suitable for weak acids such as dilute sulfuric acid and fatty acids. In these environments, it demonstrates excellent corrosion resistance with corrosion rates below 0.1 mm/year . However, it is NOT recommended for strong acids.

 

Q2: Is C5191 magnetic?

A: No, C5191 phosphor bronze is non-magnetic . This characteristic makes it particularly suitable for precision electronic applications where magnetic interference must be avoided, such as in sensitive measurement equipment and anti-magnetic instrument components .

 

Q3: What is the electrical conductivity of C5191?

A: The electrical conductivity of C5191 is approximately 13-21% IACS (International Annealed Copper Standard).

 

Q4: How does C5191 perform under high-strain-rate (high-speed) deformation?

A: C5191 exhibits significant strain rate sensitivity, meaning its mechanical properties change markedly under high-speed deformation conditions (such as high-speed stamping).

 

Q5: What is the "low-temperature annealing hardening" effect in C5191?

A: Unlike most metals that soften when annealed, C5191 exhibits a unique anneal hardening phenomenon when heat-treated at low temperatures (200-260°C).

 

Q6: How strong can C5191 actually get?

A: C5191's maximum strength depends heavily on processing. The highest published values exceed 800 MPa.

 

 

Hot Tags: C5191 Phosphor Bronze Alloy, China C5191 Phosphor Bronze Alloy manufacturers, Phosphor Bronze Plate, C51900 Phosphor Bronze, Alloy 510 Phosphor Bronze, CW106C Chromium Zirconium Copper, Aluminum Bronze Bearing, Oxygen Free Copper Pipe