Choosing Alloys for Automotive Components

## The Automotive Material Landscape | Material | Share (ICE) | Share (BEV) | Trend | |----------|-----------|-----------|-------| | Steel & Iron | 55-60% | 45-50% | Decreasing | | Aluminum | 10-15% | 15-25% | Increasing | | Copper | 1-2% | 3-5% | Increasing (EV wiring) | ## Body Structure: Advanced High-Strength Steel **Dual-phase (DP) steels**: Ferrite-martensite microstructure, 600-1000 MPa tensile strength. DP590 and DP780 for structural rails and B-pillars. **Press-hardened steel (PHS)**: 22MnB5 boron steel, heated to 900 degrees C and quenched in-die to 1500 MPa. Used for A-pillars, B-pillars, and door beams where intrusion resistance is critical. ## Closures: Aluminum **6016-T4**: Outer body panels. Formed in T4 condition, bake-hardened to T6 during paint cure (170 degrees C, 20 minutes). **6061-T6 extrusions**: Crash management systems and battery enclosures. Can replace multiple steel stampings with a single extruded cross-section. ## Powertrain **Engine blocks**: A356 aluminum casting has replaced gray cast iron in most passenger vehicles, saving 40-50% weight. **Crankshafts**: Forged 4140 or 4340 steel. Some diesel applications use ductile iron. ## EV-Specific Materials **Battery enclosures**: 6061-T6 aluminum. Some OEMs moving to gigacast A380 aluminum for single-piece underbody structures. **Copper bus bars**: C11000 ETP copper for 400V+ high-current systems. ## Weight Reduction Economics | Substitution | Weight Saving | Cost Premium | |-------------|--------------|-------------| | Mild steel to AHSS | 15-25% | 1.2-1.5x | | Steel to aluminum | 40-50% | 2-3x | | Aluminum to magnesium | 30-35% | 2-3x |