Why is High-Strength Brass the Most Suitable Material for Insert-Type Self-Lubricating Bearings?

In modern industrial equipment, self-lubricating bearings are core components that ensure the efficient and stable operation of machinery, especially in heavy-load, low-speed, or extreme conditions where traditional grease lubrication often falls short. Insert-type self-lubricating bearings, which embed solid lubricants (such as graphite, molybdenum disulfide) into the base material, can continuously release a lubricating film during friction, significantly reducing wear. However, the choice of base material directly determines the bearing's load-carrying capacity, wear resistance, and lifespan. Among numerous candidate materials, high-strength brass (such as ZCuZn25Al6Fe3Mn3, HMn58-2, etc.) stands out due to its unique physical and mechanical properties, making it the preferred material in this field.

I. Physical and Mechanical Properties of High-Strength Brass

High Strength and Load-Carrying Capacity

High-strength brass achieves solid solution strengthening and dispersion strengthening effects by adding alloy elements such as aluminum (Al), iron (Fe), and manganese (Mn). Taking the typical grade ZCuZn25Al6Fe3Mn3 as an example, its tensile strength can reach 650-750 MPa, with a hardness of HB 180-220, significantly higher than ordinary tin bronze (ZCuSn10P1 tensile strength of approximately 250 MPa, HB 90). This high strength allows it to withstand ultimate pressures of 30-50 MPa, meeting the demands of heavy-load scenarios such as mining machinery and metallurgical rolling mills.

Excellent Wear Resistance and Low Friction Coefficient

The base structure of high-strength brass is dense and uniform, with a stable friction coefficient of 0.08-0.12 under dry friction conditions, a reduction of over 30% compared to tin bronze (0.15-0.25). At the same time, its wear rate is only 0.5×10⁻⁴ mm³/(N·m) (ASTM G99 testing standard), a 58% reduction compared to aluminum bronze (1.2×10⁻⁴), significantly extending the bearing's lifespan.

Self-Lubricating Synergistic Effect

High-strength brass can pre-embed solid lubricants (such as graphite) accounting for 15-25% of the volume through powder metallurgy or casting processes. During friction, the lubricants are uniformly released and form a transfer film, combined with the base material's high thermal conductivity (70-80 W/(m·K)), effectively preventing lubrication failure caused by local overheating.

II. Comparative Analysis: High-Strength Brass vs. Other Bearing Materials

Key Advantage Summary:

• Economy: High-strength brass is approximately 20% less expensive than tin bronze and has a lifespan that is 50% longer (reaching 8000-10000 hours under heavy-load conditions).

• Environmental Adaptability: The presence of aluminum and manganese elements enhances resistance to seawater and acid-alkali corrosion, making it suitable for ships and chemical equipment.

• Reliability: Under frequent start-stop conditions or impact loads, its fatigue strength (≥200 MPa) far exceeds that of engineering plastics (approximately 30 MPa).

III. Application Cases and Data Support

According to statistics from the China Heavy Machinery Industry Association in 2023, in scenarios such as port crane slewing bearings and shield machine cutterhead bearings, the failure rate of insert bearings using high-strength brass is 42% lower than that of tin bronze, and the maintenance interval has been extended from 500 hours to 1200 hours. A metallurgical enterprise's rolling mill renovation project showed that after switching to high-strength brass bearings, the annual maintenance cost for a single piece of equipment decreased by RMB 180,000, and energy consumption reduced by 7%.

High-strength brass, with its "trinity" characteristics of high strength, low friction, and wear resistance, combined with its excellent self-lubricating synergistic effect and cost advantage, has become the "gold standard" for insert-type self-lubricating bearings. As industrial equipment evolves towards higher parameters, its irreplaceable role in complex conditions such as high loads, high temperatures, and corrosion will become increasingly prominent.

Zhejiang Mingxu Machinery Manufacturing Co., Ltd. specializes in high-strength brass self-lubricating bearings, such as graphite copper sleeves, plates, gaskets, guide blocks, and more. With over a decade of production and sales experience, our products are widely recognized and favored by customers across various industries. If you have purchasing needs, please contact us promptly at: [email protected].