Bronze Graphite Plates for Four-Die Forging Devices

Bronze-graphite sliding bearings and plates are specialized self-lubricating components designed for use in various industrial applications, especially in situations involving high loads and low speeds where traditional lubrication is impractical or undesirable. These bearings consist of a bronze alloy base embedded with graphite plugs that serve as a built-in lubricant.

Composition and Features:

• Base Material: Typically made from durable bronze alloys, such as:
  • CuSn5Zn5Pb5 (600S1): Comprising 5% each of tin, zinc, and lead.
  • CuAl10Ni5Fe5 (600S2): An aluminum bronze alloy enhanced with nickel and iron.
  • CuZn25Al6FeMn3: A robust bronze alloy.
• Graphite Inserts: Graphite is inserted into machined holes or grooves on the bronze plate, providing a self-lubricating feature that minimizes friction between the shaft and the plate.
• Pattern of Graphite Plugs: Commonly, these graphite plugs might cover about 25-30% of the surface area, typically with a diameter of 7mm, arranged strategically to ensure optimal lubrication coverage.

Applications:

• Suitable for high-load, low-speed, and intermittent swing conditions, bronze-graphite sliding plates are utilized in a variety of settings, including:
  • Automobile cover dies
  • Metal stamping dies
  • Injection molding machines
  • Metallurgical machinery
  • Pipeline supports
  • Expansion joints in bridges
  • High-temperature ducts in water-tube boilers

Performance Characteristics:

• Self-Lubricating: No need for additional lubrication.
• Load-Bearing Capacity: Can support up to 50 N/mm².
• Temperature Tolerance: Operates effectively up to 450°C (842°F).
• Low Friction Coefficient: Ensures efficient operation.
• Excellent Wear and Corrosion Resistance: Enhances durability and lifespan.

Advantages:

• Maintenance-Free: Eliminates the need for regular lubrication.
• Long Service Life and Harsh Environment Suitability: Ideal for challenging conditions where liquid lubricants are unsuitable.
• Energy Efficiency: Reduced friction lowers energy consumption.

Selection Considerations: When choosing a bronze-graphite sliding bearing or plate, it is crucial to evaluate specific factors such as load, speed, temperature, and environmental conditions. Consulting with industry experts or manufacturers can provide guidance to select the appropriate material and design for your particular needs.

Regarding Four-Die Forging Devices (FDFDs), these are specialized tools used in hydraulic forging presses to produce long-axis forgings through a four-side radial forging process. FDFDs represent an advancement in forging technology, offering improved efficiency, precision, and quality compared to traditional two-die forging methods, while being more cost-effective and versatile than specialized radial forging machines

CuSn5Zn5Pb5 (C83600 Leaded Red Brass)

Composition:

• Copper (Cu): 84-86%
• Tin (Sn): 4-6%
• Zinc (Zn): 4-6%
• Lead (Pb): 4-6%

Properties:

• Density: 8.7-8.8 g/cm³
• Tensile Strength: 276-310 MPa
• Yield Strength: 124-179 MPa
• Elongation: 30%
• Hardness (Brinell): 60-80

Applications:

• Typically used in general low-pressure valves, fittings, and decorative architecture due to its excellent machinability, reasonable strength, and corrosion resistance.

CuAl10Ni5Fe5 (C95500 Nickel Aluminum Bronze)

Composition:

• Copper (Cu): 78-82%
• Aluminum (Al): 9-11%
• Nickel (Ni): 3-5%
• Iron (Fe): 3-5%

Properties:

• Density: 7.6 g/cm³
• Tensile Strength: 758-965 MPa
• Yield Strength: 414-551 MPa
• Elongation: 12-18%
• Hardness (Brinell): 170-241

Applications:

• This alloy is often used in high-strength applications, such as in aerospace components, marine hardware, and machinery that requires resistance to wear and corrosion, particularly in seawater environments.

CuZn25Al6FeMn3 (C86300 Manganese Bronze)

Composition:

• Copper (Cu): 60-66%
• Zinc (Zn): 22-28%
• Aluminum (Al): 5-7.5%
• Iron (Fe): 2-4%
• Manganese (Mn): 2.5-5%

Properties:

• Density: 7.83 g/cm³
• Tensile Strength: 758-896 MPa
• Yield Strength: 427-621 MPa
• Elongation: 8-15%
• Hardness (Brinell): 187-229

Applications:

• Suitable for applications requiring excellent load carrying and wear resistance properties such as gears, bearings, and load-bearing members. Often utilized in heavy industrial and marine applications due to its high strength and durability in harsh environments.

These materials are widely recognized for their distinctive combinations of strength, corrosion resistance, and other mechanical properties, making them suitable for various specific applications.

bronze-graphite sliding bearings/plates for the specified forging modes:

1. Material Composition:
   The bronze-graphite sliding plates typically consist of a bronze alloy base with embedded graphite plugs. Common bronze alloys used include CuSn5Zn5Pb5 (600S1) or CuAl10Ni5Fe5 (600S2). The graphite plugs usually cover 25-30% of the total surface area and are arranged geometrically to provide optimal lubrication.
2. Load Capacity:
   The specified pressure ranges (20-80 MPa) fall within the capabilities of high-quality bronze-graphite bearings. Some sources indicate that these bearings can handle loads up to 50 N/mm² (50 MPa), while others suggest even higher capacities. The maximally loaded mode (80 MPa) is at the upper limit of typical capabilities, so special attention should be paid to material selection and design for this condition.
3. Temperature Resistance:
   The operating temperature of up to 300°C is within the acceptable range for bronze-graphite bearings. Many of these bearings are suitable for temperatures up to 450°C (842°F), so the specified temperature should not pose a problem.
4. Friction Coefficient:
   The specified friction coefficient of 0.15-0.20 aligns well with the typical performance of bronze-graphite bearings. Sources indicate that for sliding bearing plates operating within the recommended PV range, the coefficient of friction will be around 0.15.
5. PV Factor:
   The PV factors specified (2.0-3.2) are within the typical range for bronze-graphite bearings. These materials are known for their ability to handle high loads at low to medium speeds, which matches the given parameters.
6. Durability:
   Given the total annual friction distance of approximately 400,000 meters and the operating schedule (15 out of 24 hours, 3-shift model), the bronze-graphite bearings should provide good durability. These materials are known for their long service life and maintenance-free operation.
7. Mating Surface:
   The mating plate made of 55NiCrMoV6 steel with HRC 46-51 and Ra 1.6 should provide a suitable sliding surface. Bronze-graphite bearings typically perform well against hardened steel surfaces.
8. Self-Lubrication:
   The graphite plugs in the bronze matrix provide continuous self-lubrication, which is crucial for the specified operating conditions, especially considering the high temperatures and loads.

Recommendations:

1. Consider using a high-strength bronze alloy like CuAl10Ni5Fe5 (600S2) for better load capacity and wear resistance.
2. Ensure that the graphite plug pattern is optimized for the primary direction of motion in your application.
3. Monitor the maximally loaded mode closely, as it approaches the upper limits of typical bronze-graphite bearing capabilities.
4. Implement a monitoring system to track wear and performance, especially during the initial operation period.
5. Consider the possibility of additional lubrication channels for the maximally loaded mode, if feasible in your design.

In conclusion, bronze-graphite sliding bearings/plates appear to be a suitable choice for the specified forging modes, offering a good balance of load capacity, temperature resistance, and self-lubrication properties. However, careful material selection and design considerations are necessary to ensure optimal performance, especially for the maximally loaded mode.