Performance Testing Report on High-Wear-Resistant Materials for Conical Twin-Screw Barrels
1. Introduction
Conical twin-screw barrels are critical components in extrusion machines, especially for processing abrasive materials such as PVC compounds with high filler content and wood-plastic composites (WPC). The barrel’s material and surface treatment directly affect wear resistance, service life, and extrusion stability.
This report presents performance test results of several high-wear-resistant materials used in manufacturing conical twin-screw barrels.
2. Materials Tested
| Material Code | Description | Treatment/Coating |
|---|---|---|
| M1 | 38CrMoAlA Alloy Steel (nitrided) | Gas Nitriding |
| M2 | Bimetallic barrel liner (Fe-Ni based alloy) | Metallurgically bonded liner |
| M3 | Colmonoy Hardfacing Coating | Plasma Transferred Arc (PTA) welding |
| M4 | Ceramic Carbide Composite Coating | Thermal spray coating |
3. Test Methods
- Hardness Testing: Rockwell and Vickers hardness scales.
- Abrasion Resistance: ASTM G65 dry sand/rubber wheel test to simulate abrasive wear.
- Corrosion Resistance: Salt spray test (ASTM B117) for 72 hours.
- Surface Roughness: Measured before and after wear test using profilometry.
- Microstructure Analysis: Optical and scanning electron microscopy (SEM).
4. Results
| Property | M1 (Nitrided Alloy) | M2 (Bimetallic Liner) | M3 (Colmonoy PTA) | M4 (Ceramic Composite) |
|---|---|---|---|---|
| Hardness (HRC) | 58 | 52 | 62 | 70 |
| Abrasion Weight Loss (mg) | 45 | 30 | 18 | 12 |
| Corrosion Rating (1–10)* | 6 | 8 | 7 | 5 |
| Surface Roughness (Ra μm) Before | 0.8 | 0.6 | 0.5 | 0.4 |
| Surface Roughness (Ra μm) After | 2.5 | 1.2 | 0.7 | 0.6 |
*1 = severe corrosion, 10 = no corrosion
5. Discussion
- Nitrided Alloy Steel (M1): Offers good hardness but relatively higher abrasion loss and moderate corrosion resistance. Suitable for general applications with moderate filler content.
- Bimetallic Liners (M2): Significantly better abrasion and corrosion resistance due to specialized alloy. Widely used in PVC extrusion with high CaCO₃ content.
- Colmonoy Hardfacing (M3): Excellent hardness and abrasion resistance; plasma welding ensures strong metallurgical bond. Ideal for highly abrasive environments.
- Ceramic Composite Coatings (M4): Highest hardness and lowest wear rates, but moderate corrosion resistance. Emerging technology with great potential for extended barrel life.
6. Conclusion
The testing confirms that hardfaced coatings and bimetallic liners substantially improve wear resistance and service life of conical twin-screw barrels. Selection should be based on specific processing conditions and cost considerations.
7. Recommendations
- For PVC and WPC extrusion with high filler content, bimetallic liners combined with Colmonoy hardfacing on screws offer optimal performance.
- Consider ceramic composite coatings for extremely abrasive or specialized applications where maximum durability is required.
8. About Zhoushan Juyuan
Zhoushan Juyuan Machinery Co., Ltd. specializes in manufacturing high-quality conical twin-screw barrels using advanced wear-resistant materials and coatings, backed by rigorous testing to ensure reliable extrusion performance.
📧 Email: cxj.job@gmail.com
🌐 Website: https://juyuan-machinery.com/
📱 WhatsApp: +85244499051