What is the difference between tin bronze and lead brass?

Performance Characteristics

Mechanical Properties

Tin bronze: has high strength, hardness and wear resistance. With the increase of tin content, the strength and hardness of the alloy increase accordingly. For example, the tin content of about 10% of the tin bronze tensile strength of up to 300 - 400MPa. At the same time, the elastic limit of tin bronze is high, the modulus of elasticity between 100 - 120GPa, suitable for the manufacture of parts subjected to large elastic deformation, such as springs, elastic components and so on.

Lead brass: strength and hardness is lower than tin bronze, but has good plasticity and toughness. Its tensile strength is generally around 300MPa, elongation up to 30% - 50%. The cutting performance of lead brass is good, in the process of machining, lead particles can play a role in lubricating the tool, thus making the cutting smoother.\

Corrosion resistance

Tin bronze: It has good corrosion resistance in atmospheric, seawater and freshwater environments. A dense oxide film forms on the surface of tin bronze, preventing further corrosion. Especially in the medium containing chloride ions, such as seawater, its corrosion resistance is better than many other copper alloys, so it is commonly used in the manufacture of ship parts, marine engineering equipment.

Lead brass: in general atmospheric conditions also has a certain degree of corrosion resistance, but in the medium containing acidic or alkaline, its corrosion resistance is not as good as tin bronze. For example, in acidic solutions such as sulfuric acid, lead brass may dezincification corrosion, resulting in a decline in material performance.

Friction properties

Tin bronze: has a low coefficient of friction and good wear resistance. This is due to the uniform distribution of hard points in its alloy organization, which effectively resists wear during friction. For example, in plain bearing applications, tin bronze is able to withstand high loads and relative sliding speeds with reduced wear and heat generation.

Lead brass: Its friction performance is also better due to the presence of lead, which forms a lubricating film on the surface during friction, reducing the coefficient of friction and giving the material good self-lubrication. However, under high load and high speed friction conditions, the wear resistance of lead brass may not be as good as that of tin bronze.