Here’s a professional English summary comparing the bronze alloys QAl9-4 and C5191:
Material Classification & Composition
| Grade | Int’l Equivalent | Type | Composition (wt.%) | Key Characteristics |
|---|---|---|---|---|
| QAl9-4 | C63000 (ASTM) | Aluminum Bronze | Cu bal., Al 8-10, Fe 2-4 | High strength + wear resistance |
| C5191 | C5191 (JIS) | Phosphor Bronze | Cu bal., Sn 5-7, P 0.1-0.4 | High elasticity + fatigue resistance |
Mechanical Properties Comparison
| Property | QAl9-4 | C5191 |
|---|---|---|
| Tensile Strength (MPa) | 550-800 | 350-550 |
| Yield Strength (MPa) | 250-600 | 150-400 |
| Elongation (%) | 5-20 | 10-25 |
| Hardness (HB) | 110-200 | 80-160 |
| Elastic Modulus (GPa) | 115-125 | 105-115 |
| Fatigue Limit (MPa) | 200-250 | 150-200 |
Physical Properties
| Property | QAl9-4 | C5191 |
|---|---|---|
| Density (g/cm³) | 7.5-7.8 | 8.8-8.9 |
| Melting Range (°C) | 1040-1080 | 950-1020 |
| Thermal Conductivity (W/m·K) | 50-60 | 70-80 |
| Electrical Conductivity (%IACS) | 12-18 | 15-20 |
Key Performance Advantages
QAl9-4 Aluminum Bronze:
- Wear Resistance: Superior to bearing steel (dry friction coefficient 0.3-0.5)
- Corrosion Resistance: Excellent in seawater/acidic media, cavitation-resistant
- High-Temp Performance: Short-term service up to 500°C
- Castability: Good fluidity (shrinkage ≈1.8%)
C5191 Phosphor Bronze:
- Elasticity & Fatigue Resistance: Excellent spring properties (K=0.35-0.4)
- Cold Workability: Can be rolled to 0.05mm thin strips
- Wear Resistance: Self-lubricating (Sn6% content)
- EMI Shielding: Better than aluminum bronze
Processing Characteristics
| Process | QAl9-4 | C5191 |
|---|---|---|
| Hot Working | 850-950°C (oxidation protection needed) | Not recommended |
| Cold Working | Requires intermediate annealing (700°C) | Excellent (up to 90% reduction) |
| Machinability | Difficult (30% shorter tool life) | Good (similar to brass) |
| Welding | TIG/laser (special filler required) | Soldering/resistance welding |
Typical Applications
QAl9-4:
- Ship propellers, seawater pumps/valves
- Mining equipment wear plates
- High-temperature bearings (<400°C)
- Aircraft landing gear bearings
C5191:
- Precision springs/diaphragms
- Electrical connectors/relays
- Musical instrument reeds/valves
- Medical device elastic components
Material Selection Guide
- Wear/Corrosion Resistance Needed → QAl9-4 (e.g., marine environments)
- High Elasticity/Precision Forming → C5191 (e.g., electronic components)
- Cost Consideration: QAl9-4 costs 20-30% more than C5191
Special Considerations
- QAl9-4: Generates aluminum oxide chips during machining (requires dedicated dust collection)
- C5191: Requires stress relief annealing (250-300°C) after cold working
- Both Unsuitable For: Ammonia environments (stress corrosion cracking risk)
Note: QAl9-4 can achieve >900MPa tensile strength through solution treatment (950°C quenching) + aging (500°C).
Great, Together
