[China Aluminum Industry Network] Lead-based alloys with unique properties
Lead-based and tin-based bearing alloys are commonly known as babbitt alloys. These alloys typically contain 3% to 15% lanthanum, 3% to 10% copper, and in some cases up to 10% lead. Tantalum and copper are added to enhance the strength and hardness of the alloy. Their low friction coefficient, excellent toughness, good thermal conductivity, and corrosion resistance make them ideal for manufacturing sliding bearings.
Another common type is lead-tin solder, primarily composed of tin-lead alloys. Some tin solders may also include a small amount of germanium. A 38.1% lead solder alloy, often referred to as tin solder, has a melting point around 183°C. It is widely used in the electrical instrument industry, automotive radiators, heat exchangers, seals, and even in food and beverage containers.
Lead-based alloy coatings are also popular, especially when combined with tin’s anti-corrosion properties. They are applied to the surface of various electrical components, offering both protection and aesthetic appeal. Common options include tin-lead and tin-nickel coatings.
Lead-based alloys, including lead-tin and lead-free tin alloys, are used to create a wide range of soft products, such as jewelry, decorative items, and artisanal crafts. Examples include rings, necklaces, bracelets, earrings, brooches, buttons, tie clips, hats, picture frames, religious emblems, miniature sculptures, and collectible items.
When it comes to the characteristics of lead-based alloys used in soft products and craftsmanship, they offer stable properties, a low melting point, good fluidity, and minimal shrinkage. The alloys have fine grains, excellent toughness, and an appropriate level of hardness and softness. Their smooth surfaces are free from sand holes, defects, or cracks, making them ideal for polishing and plating.
Additionally, lead-based alloys exhibit strong casting performance, allowing for the production of large, thin-walled parts with a smooth finish. They can undergo various surface treatments, such as electroplating, painting, or spraying. The compact crystalline structure ensures dimensional accuracy, a fine appearance, and reduced post-processing needs.
In acidic electrolytes, lead-tin alloys can be co-deposited at very low current densities. Pb-Sn coatings show lower porosity compared to pure lead or tin coatings of the same thickness. Alloys containing 60% tin and 40% lead have a eutectic point of 183°C, offering superior welding performance over pure tin. This makes them highly suitable for aerospace and electronics industries due to their stability, low melting point, high activity, and tight structure. With fine grains, excellent toughness, and a smooth, defect-free surface, these alloys are ideal for a variety of applications.
Rotary Rings are a type of rotating seal widely used in various rotating equipment, such as rotary joints, rotary couplings, rotary connectors, etc. Its main function is to prevent liquid or gas leakage and maintain the normal operation of the equipment. In different applications, the material, structure, sealing method, size, etc. of Rotary Rings vary to adapt to different working conditions.
The materials of Rotary Rings are mainly divided into two categories: metallic and non-metallic.
Metal materials mainly include stainless steel, steel, copper, aluminum, etc., which have characteristics of high strength, corrosion resistance, wear resistance, and are suitable for rotary seals in harsh environments such as high temperature, high pressure, and high-speed.
Non metallic materials mainly include ceramics, silicon carbide, graphite, etc., which have characteristics such as high hardness, high wear resistance, and low friction coefficient. They are suitable for rotary seals under conditions such as low temperature, low pressure, and high speed.
The structure of Rotary Rings is mainly divided into three types: unidirectional rotation, bidirectional rotation, and rotational stationary.
1. Unidirectional rotating structure
The Rotary Rings with a unidirectional rotation structure can only rotate in one direction and are suitable for devices with only unidirectional rotation.
The Rotary Rings with a bidirectional rotation structure can rotate in two directions, suitable for devices that require bidirectional rotation.
The Rotary Rings with a rotating stationary structure are composed of a rotating ring and a stationary ring. The rotating ring contacts the stationary ring during rotation to achieve sealing, suitable for equipment that requires a rotating stationary seal.
The sealing methods of Rotary Rings are mainly divided into mechanical sealing and liquid sealing.
Mechanical sealing is achieved through the contact surface between the rotating ring and the stationary ring, which has the characteristics of high reliability, long service life, and simple maintenance. It is suitable for rotary sealing in harsh environments such as high speed, high temperature, and high pressure.
Liquid sealing is achieved by injecting liquid between the rotating ring and the stationary ring, which has the characteristics of good sealing performance, low friction coefficient, and preventing dry friction. It is suitable for rotary sealing under low speed, low temperature, low pressure, and other conditions.
The size of Rotary Rings is mainly determined by the equipment requirements, including inner diameter, outer diameter, thickness, shaft diameter, etc.
Rotary Seals,Rotary Lip Seal,Rotating Shaft Seal,V Seals
DG Zhongxingshun Sealing Products Factory , https://www.zxs-seal.com