Bronze and Alloys of Bronze

What is Bronze?

Bronze is an alloy of copper (Cu) and tin (Sn) as primary alloying. Various alloys of bronze are made by alloying it with other alloying elements such as Aluminum, phosphorus, Nickel, Silicon, Manganese and Tin etc. to enhance its mechanical (tensile & yield), chemical (etching), corrosion resistance and technological (machining, castability) properties.

It has been used for centuries to make everything from sculptures to coins. The Bronze Age was a period in which societies across the world began to use bronze to make tools and weapons.

This new technology allowed for the creation of stronger and more durable items than had been possible before.

Bronze age Axes made from Bronze (Source- Wikipedia)

Tools and weapons made of bronze were superior to those made of stone or copper, and they quickly became popular. The first true Bronze Age cultures appeared in southern Russia around 3000 BC.

What are the alloy metals in bronze?

There are numerous alloy metals in bronze, but the most common are copper and tin. There are also zinc, manganese, aluminum, iron, lead, and silicon. The proportions of these metals vary depending on the type of bronze.

Alloys of Bronze tin-bronze-color-
Different shapes of Tin Bronze Material

Following are the main alloy metals in bronze grades:

  1. Copper: Main constitute
  2. Tin: secondary element
  3. Aluminum: Alloying element
  4. Silicon: Alloying element
  5. Phosphorus: Alloying element
  6. Lead: Alloying element
  7. Manganese: Alloying element

Bronze Alloys List

There are many different types of bronze alloys, where each one has its own unique features and properties. Here is a list of some of the most common bronze alloys, along with a brief description of each one:

  1. Nickel Aluminum Bronze
  2. Aluminum Bronze
  3. Phosphor Bronze
  4. Silicon Bronze
  5. Leaded Bronze
  6. Tin Bronze
  7. Manganese Bronze
  8. Silicon Aluminum Bronze
  9. Nickel Silver Bronze
  10. Lead Free Bronze

Nickel Aluminum Bronze

Nickel aluminum bronze alloys are known for their high strength and corrosion resistance due to high aluminum content. These properties make them ideal for use in a variety of industries, including marine, oil & gas and aerospace.

C95500 Nickel Aluminum Bronze 

The most common alloy used in marine applications is C63000, which contains 5-7% aluminum. This alloy offers excellent resistance to seawater corrosion and pitting, making it an ideal choice for boat hulls and other marine components.

Aerospace applications typically require an alloy with higher strength and toughness than what is available in AMS 4590, AMS 4640, AMS 4880 and AMS 4881.

Aluminum Bronze

Aluminum bronze is an alloy of aluminum and bronze. The ratio of aluminum to bronze can vary but is typically between 10% and 20%. Aluminum bronzes are used in a variety of applications where their high strength and corrosion resistance are advantageous.

 C95400 aluminum bronze is widely used cast Aluminum bronze that have high strength, corrosion and wear resistance. Other commonly used Aluminum bronze are C61000, C61400, C61800, C62300 and CuAl11Ni5Fe5.

Phosphor Bronze

Phosphor Bronze is an alloy that contains 0.5%-11% tin (Sn), 0.01%-0.35% phosphorous (P) and balance copper (Cu). Phosphor Bronze is known for its high strength and corrosion resistance.

The addition of tin to copper increases the strength of the alloy, while the addition of phosphorous increases the wear resistance & stiffness. Phosphor Bronze is commonly used in electrical applications due to its high conductivity and low contact resistance.

Phosphor Bronze
Phosphor Bronze

Notable Phosphorus bronze grades are C51000, C52100, C52400 and C54400. The common ASTM material specifications are ASTM B139 and ASTM B140.

Silicon Bronze

Silicon Bronze is an alloy made up of copper (approx. 95%, silicon (1-2%), Iron and Manganese. Silicon bronze is an excellent bearing and load material due to its high copper content. They have good weldability.

Silicon Bronze
C65610 Silicon Bronze Grade

The most common grades are C65100, AMS 4616, C65300 and C65500. Silicon bronze is also resistant to corrosion and has good weldability.

Leaded Bronze

Lead bronze is an alloy of lead, tin and copper. It has a low melting point and is used for casting. Lead bronze is strong and resistant to corrosion. It is used in the production of bearings, gears and valves.

Leaded bronze has good machinability, corrosion & wear resistance. Commonly used Leaded Bronze grades are C31400, C31600, C66100, C92200, C92300 and C92500.

Tin Bronze

Tin bronze is a strong, hard and very ductile metal that is resistant to corrosion in marine and brine environments. It is used in fittings, bearings and impellers.

Tin Bronze generally contains 85-90% Copper, 7-9% Tin and 3-5% Zinc with other minor alloying elements. Commonly used Tin Bronze grades are C90200, C90300, C90500, C90700, C91100 and C93200.

Manganese Bronze

Manganese bronze is an alloy of iron, manganese, lead and aluminum that offers high strength and excellent corrosion resistance.

It is often used in aerospace applications as well as fasteners and oil & gas industries. The addition of manganese increases the strength of the alloy while the lead improves machinability. Aluminum is added to improve corrosion resistance.

The commonly used Manganese Bronze grades are C66800, C67300, C67310, C67400, C67410 and C86300.

Silicon Aluminum Bronze

Silicon aluminum bronze is an alloy that has high strength and lubrication properties. It is also free-machining and anti-galling. Silicon aluminum bronze is used in landing gear parts, bearings, valves, pumps, and cams.

The lubrication properties of the alloy make it ideal for use in moving parts such as valves, pumps, and cams.

Most commonly used Silicon Aluminum Bronze grades are C63600 and C64200.

Nickel Silver Bronze

Nickel silver, also known as German silver or dairy bronze, is an alloy of copper, lead, tin, nickel, and zinc. It is named for its silvery appearance, but it is not actually made of silver. Nickel silver is a medium-strength alloy that is resistant to corrosion.

It is often used in jewelry and flatware because it looks like sterling silver but is much less expensive. Nickel silver is also used in musical instruments, coins, and electrical contacts. Common grades of Nickel Silver Bronze are C97600 and C97800.

Lead Free Bronze

Lead Free Bronze alloys are those that contain a high percentage of Copper and Zinc, with small amounts of Tin, Manganese, Iron, Antimony, and other elements.

They are used in a variety of applications where strength, durability, and resistance to corrosion are required. Common grades of Lead-free bronze are C69300, C90300 and C95800.

Alloys of Bronze Specifications

Alloys of bronze are made up of a combination of different metals that are combined to create a material with specific properties.

Bronze alloys are manufacturer according to the industrial specification. Most notably are ASMT and AMS.

Commonly used Bronze alloy material specifications are:

  1. ASTM SB-98
  2. ASTM SB-150
  3. ASTM SB-151
  4. ASTM SB-148
  5. ASTM SB-171
  6. ASTM SB-283
  7. ASTM SB-359

Properties of Bronze

Bronze is an alloy that is made up of copper and tin. It has a wide range of properties that make it useful for a variety of applications.

Bronze is strong and resistant to wear, making it an ideal material for use in bearings and gears. It also has good electrical and thermal conductivity, making it suitable for electrical applications. Bronze is non-magnetic, so it can be used where a magnetic field would be undesirable.

The main properties of Bronze are:

1. Bronze is strong and durable. It is resistant to corrosion and can withstand high temperatures.

2. Bronze has a low melting point, which makes it easy to cast into shapes.

3. Bronze is conductive and can be used for electrical applications.

4. Bronze has a pleasing appearance and can be polished to a high shine.

5. Bronze is non-magnetic and does not rust easily.

6. Bronze is tough and resists wear and tear.

7. Bronze alloys can be tailored to meet specific engineering requirements.  For example, bronze with a higher tin content is more malleable than one with a lower tin content.

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