Development and Application of High-Strength Aluminum Alloy Materials for Plastic Fasteners
Development and Application of High-Strength Aluminum Alloy Materials for Plastic Fasteners
As new energy vehicles, medical devices, and high-end consumer electronics rapidly develop, demand for high-performance, lightweight, and corrosion-resistant plastic fasteners continues to surge. Traditional POM and PA66 materials face bottlenecks in strength, creep resistance, and weatherability under extreme conditions. High-strength aluminum alloys—offering a density just 1/3 that of steel, specific strength (strength/density) 1.8× higher than stainless steel, excellent cold/hot workability, and natural passivation film corrosion resistance—have become the core material for next-generation plastic fastener reinforcement frames. This article provides a panoramic analysis of two leading grades—PA66-T6 and POM—from materials science to engineering application.
I. Material Properties & Heat Treatment Processes
1. PA66-T6 Aluminum Alloy: Mg-Si based, with minor Cu and Cr additions. T6 process: 530°C solutionizing for 1h → water quench → 175°C artificial aging for 8h. Yield strength ≥276 MPa, elongation >12%, excellent cold bending performance—ideal for complex fasteners (e.g., flange nuts, double-end studs).
2. POM (Polyoxymethylene) Enhanced System: Based on high-crystallinity POM, reinforced with 20% short glass fibers and 3% nano-silicon dioxide, tensile strength reaches 138 MPa, notched impact strength improves by 40%, with no fracture at -40°C. In BYD's 'Blade Battery' tray fixation, it replaces M6 stainless steel bolts, reducing weight by 42g per point and over 1.2kg per pack.
II. Mechanical Performance & Environmental Adaptability Test Data
In tests by the National Nonferrous Metals Quality Supervision & Inspection Center:
- PA66-T6: Room-temperature tensile strength 312 MPa, yield strength 285 MPa, elongation 15.2%; in GB/T 10125 acetic acid salt spray, only slight whitening after 3000 hours, no substrate corrosion
- POM: Room-temperature tensile strength 138 MPa, notched impact strength 42 kJ/m², no fracture at -40°C; in ISO 9227 neutral salt spray, no pitting after 7200 hours—2.3× longer than standard POM
III. Large-Scale Application Cases
1. BYD Han EV Electric Drive System: PA66-T6 high-strength aluminum alloy anchor bolts (M24×300 mm) reduced weight per bolt by 62%, decreasing total mounting weight by 18.7%, and increasing installation efficiency by 2.1×.
2. Siemens Healthineers CT Equipment: POM aluminum alloy rail connectors with micro-arc oxidation coating showed zero galvanic corrosion after 5 years of field service, with O&M costs at just 38% of stainless steel solutions.
Conclusion
High-strength aluminum alloys are not simple replacements for traditional plastics—they are the foundational enablers of lightweight, intelligent, and long-life plastic fasteners. The synergistic application of PA66-T6 and POM is building a comprehensive material solution covering 'high strength–high toughness–high corrosion resistance' across all scenarios. Looking ahead, nano-ceramic reinforced aluminum matrix composites and AI-driven materials genome engineering will usher in a new era for plastic fastener materials.