Views: 0 Author: Site Editor Publish Time: 2026-04-09 Origin: Site
White Metal Sliding Bearings—In-Depth Analysis Report on the Performance of Babbitt Alloys
Abstract:
This report conducts an in-depth analysis of the performance characteristics, application scenarios, economic benefits, and practical cases of different Babbitt alloys used in white metal journal bearings. As the core material for sliding bearings, Babbitt alloy offers irreplaceable advantages under heavy-load, high-speed, precision, and special operating conditions due to its excellent anti-friction properties, load-bearing capacity, and emergency running characteristics. Through scientific selection and application, Babbitt alloy can significantly enhance equipment reliability, reduce maintenance costs, and extend service life.
Typical Microstructure of Tin-based Babbitt Alloys:
①Hard Phase (Load-bearing Skeleton): SbSn, Cu₆Sn₅
②Soft Matrix (Anti-friction Medium): α solid solution (Sn-Sb solid solution), which provides excellent anti-friction properties and forms a lubricating film during the friction process.
Typical Microstructure of Lead-based Babbitt Alloys:
①Hard Phase (Load-bearing Skeleton): SbSn, Cu₂Sb
②Soft Matrix (Anti-friction Medium): Pb-Sb solid solution, with a lead-rich phase containing a small amount of Sn.
The primary mechanisms underlying the formation of Babbitt alloy properties are as follows:
Load-bearing Mechanism: The hard phase forms a load-bearing skeleton to bear the main load.
Anti-friction Mechanism: The soft matrix undergoes plastic deformation during the friction process to form a continuous lubricating film.
Embeddability Mechanism: The soft matrix can embed foreign hard particles to protect the journal.
Conformability Mechanism: The material can accommodate minor deformations and misalignment of the shaft.
Emergency Running Mechanism: During short-term oil starvation, the soft matrix melts to form temporary lubrication.
Performance index | SnSb11Cu6 | SnSb8Cu4 | SnSb4Cu4 | PbSb15Sn10 | PbSb10Sn6 |
Density (g/cm³) | 7.38 | 7.34 | 7.28 | 10.1 | 9.8 |
Melting point (°C) | 240-260 | 230-250 | 220-240 | 260-280 | 240-260 |
Coefficient of linear expansion (10⁻⁶/°C) | 23 | 24 | 25 | 29 | 27 |
Thermal conductivity (W/m·K) | 50.2 | 52.1 | 54.3 | 35.6 | 38.2 |
Specific heat volume (J/kg·K) | 226 | 228 | 230 | 130 | 140 |
Electrical resistivity (μΩ·m) | 0.145 | 0.142 | 0.138 | 0.210 | 0.195 |
Performance index | SnSb11Cu6 | SnSb8Cu4 | SnSb4Cu4 | PbSb15Sn10 | PbSb10Sn6 |
Brinell Hardness HB | 30-35 | 25-30 | 20-25 | 22-28 | 18-24 |
Compressive strength (MPa) | ≥120 | ≥100 | ≥80 | ≥90 | ≥75 |
Strength of extension (MPa) | 90-110 | 75-90 | 60-75 | 65-80 | 55-70 |
Elongation (%) | 6-9 | 8-12 | 10-15 | 4-7 | 6-10 |
Elasticity modulus (GPa) | 52 | 50 | 48 | 28 | 30 |
Fatigue limit (MPa) | 45 | 40 | 35 | 30 | 25 |
Operating Conditions | SnSb11Cu6 | SnSb8Cu4 | SnSb4Cu4 | PbSb15Sn10 | PbSb10Sn6 |
Coefficient of starting friction | 0.12-0.15 | 0.10-0.13 | 0.08-0.11 | 0.15-0.18 | 0.13-0.16 |
Operating friction coefficient | 0.005-0.008 | 0.004-0.007 | 0.003-0.006 | 0.008-0.012 | 0.006-0.010 |
Boundary lubrication | 0.08-0.12 | 0.07-0.10 | 0.06-0.09 | 0.12-0.16 | 0.10-0.14 |
Dry friction | 0.25-0.35 | 0.22-0.32 | 0.20-0.30 | 0.30-0.40 | 0.28-0.38 |
Wear type | Performance of tin-based alloys | Performance of lead-based alloys | Optimization measure |
Adhesive wear | Excellent (low adhesion tendency) | Good | Improve surface finish |
Abrasive wear | Good (resistant to hard phase) | Medium | Enhance lubrication and filtration |
Fatigue wear | Excellent (with high fatigue limit) | Good | Optimize load distribution |
Corrosive wear | Excellent (corrosion-resistant) | Require surface treatment | Choose suitable alloy |
Fretting wear | Good | Medium | Improve the coordination accuracy |
Temperature range | SnSb11Cu6 | SnSb8Cu4 | SnSb4Cu4 | PbSb15Sn10 | PbSb10Sn6 |
Minimum operating temperature | -50°C | -60°C | -70°C | -40°C | -50°C |
Optimum working temperature | 60-100°C | 50-90°C | 40-80°C | 70-110°C | 60-100°C |
Maximum working temperature | 150°C | 140°C | 130°C | 160°C | 150°C |
Short-term tolerance temperature | 180°C | 170°C | 160°C | 200°C | 190°C |
Working medium | Compatibility of tin-based alloys | Compatibility of lead-based alloys | Safeguard procedures |
Fresh water | Excellent | Good | No special protection is required. |
Seawater | Excellent | Require surface treatment | Galvanized or coated |
Mineral oil | Excellent | Excellent | Standard lubrication |
Synthetic oil | Excellent | Good | Pay attention to compatibility |
Acid-base solution | Good (PH 4 - 10) | Limited | Select corrosion-resistant alloys |
Steam | Good | Medium | Strengthen sealing |
To meet the bearing performance requirements under different working conditions, a standardized selection system for White Metal Bearings (Babbitt Alloy Bearings) is established by integrating two core dimensions—load-speed and environment-precision—providing a precise selection basis for diverse industrial scenarios:
Load conditions Speed range | Low speed (< 500 rpm) | Medium speed (500 - 1500 rpm) | High Speed (>1500rpm) |
Heavy Load (>30MPa) | SnSb11Cu6PbSb15Sn10 | SnSb11Cu6 | SnSb11Cu6 |
Medium load (15 - 30 MPa) | SnSb8Cu4PbSb10Sn6 | SnSb8Cu4 | SnSb4Cu4 |
Light load (<15MPa) | SnSb4Cu4 | SnSb4Cu4 | SnSb4Cu4 |
B.Environment - Precision Selection
Environmental conditions Precision requirements | General precision (±0.1mm) | Precision (±0.05mm) | High Precision (±0.02mm) |
Corrosion environment | SnSb8Cu4 | SnSb4Cu4 | SnSb4Cu4 |
High-Temperature Environment | SnSb11Cu6 | SnSb11Cu6 | SnSb11Cu6 |
Ambient Temperature Clean Environment | PbSb10Sn6 | SnSb8Cu4 | SnSb4Cu4 |
Economic applications | PbSb15Sn10 | PbSb10Sn6 | SnSb8Cu4 |
a.Large Steam Turbine Bearings
①Recommended Alloy: SnSb11Cu6 (high load-bearing capacity, suitable for high-speed conditions)
②Operating Parameters: Working load 25–35 MPa, working speed 1500–3000 rpm
③Structural Design: Bearing wall thickness 3–5 mm; adopt combined circumferential and axial oil grooves for oil supply to ensure full-area lubrication
b.Hydro Turbine Bearings
①Recommended Alloy: SnSb8Cu4 (medium load-bearing capacity, suitable for medium-low speed)
②Operating Parameters: Working load 15–25 MPa, working speed 75–600 rpm
③Structural Design: Bearing wall thickness 4–6 mm; must meet water lubrication compatibility and undergo special anti-corrosion treatment
Core adaptation to harsh operating conditions such as seawater corrosion, heavy-load impact, and water lubrication, with component-specific selection as follows:
a.Marine Tail Shaft Bearings
①Operating Conditions: Seawater lubrication, high corrosion, continuous operation
②Recommended Alloy: SnSb8Cu4 (prioritizing corrosion resistance)
③Technical Requirements: Surface tin plating of 0.05–0.1 mm; equipped with a water groove cooling system; add biological attachment protection measures
b.Rudder System Bearings
①Operating Conditions: Low speed, heavy load, impact loads
②Recommended Alloy: SnSb11Cu6 (heavy-load impact resistance)
③Technical Requirements: Increase wall thickness and adopt impact-resistant structural design; strengthen the lubrication system
④General Selection: For propellers/deck machinery, SnSb8Cu4 (corrosion-resistant) is preferred; for heavy-load conditions, SnSb11Cu6 is selected.
Adapted to harsh operating conditions such as impact loads, dust, high temperature, and heavy loads:
a.Mine Crusher Bearings
①Operating Conditions: Strong impact loads, dusty environment
②Recommended Alloy: PbSb15Sn10 (cost-effective, impact-resistant)
③Technical Requirements: Optimize structure for cost reduction; strengthen dust-proof sealing and lubrication filtration systems
b.Steel Rolling Mill Bearings
①Operating Conditions: High temperature, continuous heavy loads
②Recommended Alloy: SnSb11Cu6 (high-temperature resistant, high load-bearing capacity)
③Technical Requirements: Adopt temperature-resistant structural design; configure forced cooling system and use high-temperature special lubricant
With low friction, high precision, low hardness, and stable operation as core requirements:
a.Precision Grinder Spindle Bearings
①Operating Conditions: High speed, ultra-high precision
②Recommended Alloy: SnSb4Cu4 (low hardness, low friction)
③Technical Requirements: Fit clearance of 0.05–0.08% of shaft diameter; supporting system: constant temperature lubrication system
b.Coordinate Measuring Machine Guides
①Operating Conditions: Low-speed precision movement, extremely low friction
②Recommended Alloy: SnSb4Cu4
③Technical Requirements: Precise control of preload, implement high-grade cleanliness standards
Cost classes | The proportion of rolling bearings | The proportion of white metal bearings | Variation analysis |
Initial procurement cost | 100% | 60-80% | Reduce 20-40% |
Installation and commissioning costs | 100% | 70-90% | Reduce 10-30% |
Operating energy consumption cost | 100% | 85-95% | Reduce 5-15% |
Maintenance and upkeep costs | 100% | 30-50% | Reduce 50-70% |
Inventory cost of spare parts | 100% | 40-60% | Reduce 40-60% |
Downtime loss cost | 100% | 30-40% | Reduce 60-70% |
Disposal cost for waste recycling | 100% | 20-30% | Reduce 70-80% |
Operation condition | Rolling bearing energy consumption | Energy consumption of white metal bearings | Energy-saving ratio |
Initialization phase | 100% | 85% | 15% |
Rated operation | 100% | 92% | 8% |
Partial load | 100% | 88% | 12% |
Variable working condition | 100% | 90% | 10% |
Maintenance project | Frequency of rolling bearings | Frequency of white metal bearings | Extension factor |
Routine inspection | Once a week | Once a month | 4 times |
Lubrication replacement | Every three months | Every twelve months | 4 times |
Condition monitoring | Every one month | Once a season | 3 times |
Preventive maintenance | Every six months | Every twenty four months | 4 times |
Overhaul period | Every two years | Every five years | 2.5 times |
Failure Type | MTBF of Rolling Bearing | MTBF of White Metal Bearing | Reliability Improvement |
Fatigue Failure | 20,000 hours | 50,000 hours | 2.5 times |
Wear Failure | 15,000 hours | 40,000 hours | 2.7 times |
Lubrication Failure | 10,000 hours | 30,000 hours | 3.0 times |
Installation Failure | 25,000 hours | 60,000 hours | 2.4 times |
Overall MTBF | 17,500 hours | 45,000 hours | 2.6 times |
Resource Type | Rolling bearing consumption | Consumption of white metal bearings | Savings ratio |
Steel consumption | 100% | 60% | 40% |
Oil consumption | 100% | 40% | 60% |
Spare parts consumption | 100% | 30% | 70% |
Packing material | 100% | 50% | 50% |
Transportation energy consumption | 100% | 70% | 30% |
White Metal Bearings achieve comprehensive cost optimization across their entire lifecycle: they not only directly reduce initial investment during the procurement stage but also deliver a dramatic reduction in long-term hidden costs such as operation & maintenance (O&M), energy consumption, and downtime. Particularly in industrial scenarios involving heavy loads, impacts, and continuous operation, their cost advantage continues to amplify with the service life of the equipment, creating long-term, stable economic benefits for enterprises.
Chinese Grade GB/T 1174/8740 | International Standard ISO | American ASTM | Russian ГОСТ | Alloy Type |
ZChSnSb11-6（SnSb11Cu6） | ISO 4381 | ASTM B23 | Б83 | Tin - based |
ZChSnSb8-4（SnSb8Cu4） | ISO 4381 | ASTM B23 | Б88 | Tin - based |
ZChSnSb4-4（SnSb4Cu4） | ISO 4381 | ASTM B23 | Б89 | Tin - based |
ZChPbSb15-10（PbSb15Sn10） | ISO 4382 | ASTM B23 | Б16 | Lead - based |
ZChPbSb10-6（PbSb10Sn6） | ISO 4382 | ASTM B23 | Б10 | Lead - based |
