Commonly used die casting aluminum alloys form the backbone of modern manufacturing, combinant des propriétés légères, bonne coulabilité, et des performances polyvalentes pour répondre à divers besoins industriels. Des pièces de moteur automobile aux coques d'appareils électroniques, ces alliages permettent la production en série de complexes, composants de haute précision par moulage sous pression haute pression. This article breaks down the key types of commonly used die casting aluminum, their characteristics, process advantages, scénarios d'application, and selection criteria—helping you pick the right alloy for your specific manufacturing needs.
1. Key Types of Commonly Used Die Casting Aluminum Alloys
The most widely adopted die casting aluminum alloys fall into two main categories: aluminum-silicon-copper (Al-Si-Cu) série (represented by ADC12) and industrial pure aluminum (represented by AL99.70 and AL99.70A). Below is a 总分结构 with detailed comparisons:
1.1 ADC12 (Al-Si-Cu Series): The Workhorse Alloy
ADC12 is the most commonly used die casting aluminum alloy, accounting for over 60% of global die casting applications. Its balanced properties make it ideal for high-volume production.
| Attribute | Détails | Industrial Significance |
| Composition | Base: Aluminium (≥85%); Key alloying elements: Silicium (9.5–12%), Cuivre (1.5–3.5%); Trace elements: Manganèse (≤0,5%), Magnésium (≤0.3%) (some variants add these to boost strength). | Silicon improves fluidity (critical for filling thin-walled cavities); copper enhances tensile strength—striking a balance between castability and mechanical performance. |
| Core Characteristics | – High Fluidity: Easily fills complex mold cavities (even for parts with 0.5–1 mm thin walls).- Good Dimensional Accuracy: Achieves ISO 8062 CT6–CT7 tolerance (±0.1–0.2 mm for small parts).- Moderate Mechanical Properties: Résistance à la traction (220–280 MPa), dureté (80–100 HB); elongation is lower than pure aluminum (3–5% contre. 10–15%). | Meets the needs of most non-load-bearing and light-load components, where castability and cost-effectiveness matter more than ultra-high strength. |
| Applications typiques | Automobile: Engine mounts, carters de transmission, door handle brackets.Electronics: Smartphone charger shells, router housings, LED heat sink bases.Home Appliances: Air conditioner compressor covers, washing machine control panels. | Its versatility makes it the “go-to” alloy for manufacturers seeking a balance of performance and affordability. |
1.2 AL99.70 & AL99.70A (Industrial Pure Aluminum): High-Purity Options
These alloys are part of the 1XXX series (industrial pure aluminum) and are used for applications requiring high purity and specific physical properties. The table below contrasts their key differences:
| Feature | AL99.70 | AL99.70A | Key Impact on Applications |
| Purity & Composition | Aluminum content ≥99.70%; Silicon content ≤0.10%; Other impurities (iron, cuivre) ≤0.30%. | Aluminum content ≥99.70%; Silicon content ≤0.08% (stricter than AL99.70); Total impurities ≤0.25%. | AL99.70A’s lower silicon and impurity levels reduce surface defects, making it better for decorative parts or components sensitive to impurity-induced corrosion. |
| Identification Marking | Color code: A red vertical line on the ingot or packaging. | Color code: A red horizontal line on the ingot or packaging. | Simple visual distinction helps prevent mix-ups during material handling—critical for high-precision production lines. |
| Core Properties | – Haute conductivité électrique (60–65% IACS).- Bonne résistance à la corrosion (natural oxide layer forms quickly).- Low strength (tensile strength 90–120 MPa) but high ductility (elongation 12–15%). | Same as AL99.70, with slightly better electrical conductivity (63–68% IACS) et résistance à la corrosion (due to fewer impurities). | Suitable for parts where purity, conductivité, or corrosion resistance is prioritized over strength. |
| Applications typiques | AL99.70: Low-voltage electrical connectors, decorative trim for furniture.AL99.70A: High-precision electronic components (par ex., boîtiers de capteurs), medical device casings (non implantable), architectural decorative panels. | AL99.70A is preferred for medical and electronic applications, where even trace impurities can affect performance or biocompatibility. |
2. Process Advantages of Commonly Used Die Casting Aluminum
The popularity of these die casting aluminum alloys is not just due to their material properties—their compatibility with high-pressure die casting processes amplifies their value. Below is a linear breakdown of key process advantages, supported by data:
2.1 High-Pressure High-Speed Forming: Enabling Complexity
- Paramètres du processus: Uses 2,000–15,000 kPa pressure and 0.5–5 m/s filling speed to inject molten aluminum into molds.
- Résultat: Produces parts with intricate features (par ex., canaux internes, micro-trous) that are hard to achieve with sand casting or CNC machining. Par exemple, an ADC12 automotive sensor housing with 3 trous internes (φ1 mm each) can be cast in one step—no post-drilling needed.
- Efficacité: A single die casting machine can complete 1,000–3,000 cycles per day for ADC12 parts, far outpacing traditional manufacturing (par ex., 100–200 parts/day for sand casting).
2.2 Précision améliorée & Finition de surface
- Précision dimensionnelle: Comme mentionné plus tôt, ADC12 achieves CT6–CT7 tolerance, while AL99.70/AL99.70A (with stricter process control) can reach CT5–CT6 (±0.05–0.1 mm). This reduces post-machining by 70–80% compared to sand casting.
- Qualité des surfaces: The high-pressure process delivers a surface finish of Ra 1.6–6.3 μm for ADC12, and Ra 0.8–3.2 μm for AL99.70A (with optimized mold polishing). For many applications (par ex., electronic device shells), this eliminates the need for additional grinding or polishing.
2.3 Improved Material Performance Post-Processing
- Force & Dureté: While as-cast ADC12 has moderate strength, traitement thermique (par ex., T6) can boost its tensile strength by 15–20% (to 250–320 MPa). AL99.70/AL99.70A can be cold-worked (par ex., rolling) to increase hardness by 30–40% (depuis 25 HB to 35–38 HB).
- Résistance à la corrosion: Both ADC12 and AL99.70/AL99.70A benefit from surface treatments:
- Anodisation: Creates a 10–20 μm oxide layer, amélioration de la résistance à la corrosion (ADC12 withstands 48-hour salt spray testing; AL99.70A lasts 72+ heures).
- Revêtement: Galvanoplastie (nickel, chrome) or powder coating enhances aesthetics and durability for decorative parts.
3. Core Application Areas: Industry-by-Industry Breakdown
Commonly used die casting aluminum alloys serve diverse sectors, each leveraging their unique strengths. The table below summarizes key applications and alloy choices:
| Industrie | Key Components | Preferred Alloy | Rationale |
| Automobile | Engine mounts, carters de transmission, body structural parts, Supports de batterie EV. | ADC12 (primary); AL99.70A (garniture décorative). | ADC12’s castability and cost-effectiveness meet high-volume automotive needs; AL99.70A’s corrosion resistance suits exterior trim. |
| Electronic Appliances | Cadres d'appareil (téléphones intelligents, comprimés), dissipateurs de chaleur, connecteurs, charger shells. | ADC12 (most components); AL99.70A (high-precision sensors). | ADC12’s thin-wall capability fits miniaturized electronics; AL99.70A’s purity avoids signal interference in sensors. |
| Machinerie & Ingénierie | Hydraulic valve bodies, corps de pompe, precision gearbox covers. | ADC12 (primary); AL99.70 (low-pressure valves). | ADC12’s dimensional accuracy ensures tight fits for hydraulic parts; AL99.70’s corrosion resistance suits fluid-handling applications. |
| Emerging Fields (NEV) | Integrated battery housings, carters de moteur, charging port components. | ADC12 (pièces structurelles); AL99.70A (high-conductivity connectors). | ADC12’s strength supports battery weight; AL99.70A’s conductivity enhances charging efficiency. |
4. How to Select the Right Commonly Used Die Casting Aluminum Alloy
Choosing between ADC12, AL99.70, and AL99.70A requires evaluating four key factors. Use this step-by-step guide:
4.1 Define Core Requirements
- Mechanical Needs: If the part is load-bearing (par ex., automotive engine bracket), ADC12’s higher strength is better. For non-load-bearing parts (par ex., garniture décorative), AL99.70/AL99.70A suffices.
- Purity & Résistance à la corrosion: For medical devices or coastal applications, AL99.70A’s low impurities and superior corrosion resistance are critical. For indoor electronics, ADC12 (with anodizing) is cost-effective.
- Electrical/ Thermal Conductivity: For heat sinks or electrical connectors, AL99.70/AL99.70A’s higher conductivity (60–68% IACS) outperforms ADC12 (40–45% IACS).
4.2 Consider Process Compatibility
- Part Complexity: ADC12’s high fluidity is ideal for complex, thin-walled parts. AL99.70/AL99.70A has lower fluidity—avoid using them for parts with <1 mm walls or intricate cavities.
- Volume de production: Pour les tirages à gros volume (>10,000 parts), ADC12’s lower cost and faster casting speed reduce per-unit expenses. Pour les petits lots (<1,000 parties), AL99.70/AL99.70A’s higher material cost is less impactful.
4.3 Evaluate Total Cost
- Coût du matériel: ADC12 is 15–20% cheaper than AL99.70, and AL99.70A is 5–10% more expensive than AL99.70 (due to stricter purification).
- Post-Processing Cost: AL99.70A requires less surface treatment (par ex., no extra polishing for decorative parts), which may offset its higher material cost. ADC12 may need additional machining for high-precision features.
Yigu Technology’s Perspective
Chez Yigu Technologie, we see commonly used die casting aluminum alloys as the foundation of efficient manufacturing. Pour les clients automobiles, we recommend ADC12 for engine components—optimizing its casting parameters (8,000 pression en kPa, 2 m/s filling speed) to reduce defects by 30%. For electronic clients needing high-purity parts, we use AL99.70A with custom anodizing (15 couche de µm) to meet 72-hour salt spray standards. We also help clients balance cost and performance: Par exemple, using ADC12 for smartphone middle frames (rentable) and AL99.70A for internal connectors (haute conductivité). Finalement, the right alloy isn’t just about properties—it’s about aligning with your product’s function, volume, et budget.
FAQ
- Can ADC12 be used for load-bearing automotive parts?
Oui, but with limitations. ADC12 works for light-load parts (par ex., supports de moteur, transmission covers) with tensile strength requirements <280 MPa. For heavy-load parts (par ex., supports de suspension), we recommend upgrading to A380 (a stronger Al-Si-Cu alloy) or combining ADC12 with reinforcing ribs in the mold design.
- What’s the main reason to choose AL99.70A over AL99.70?
AL99.70A’s stricter impurity controls (lower silicon, total impurities ≤0.25%) make it better for applications where corrosion resistance or surface quality is critical. Par exemple, medical device casings or architectural trim—AL99.70A’s cleaner composition reduces the risk of surface pitting or impurity-induced failure.
- Do commonly used die casting aluminum alloys require post-treatment?
La plupart le font, but the type depends on the alloy and application. ADC12 often needs anodizing (pour la résistance à la corrosion) or CNC trimming (pour la précision). AL99.70/AL99.70A may only need light polishing (pour pièces décoratives) or no treatment at all (for internal electrical components, where conductivity is prioritized over aesthetics).