What is ADC12 aluminum and when should you specify it?
ADC12 is a high-silicon, aluminum–silicon–copper alloy defined in JIS H 5302 for high-pressure die casting (HPDC). Engineers choose it when parts have thin walls, long flow paths, dense ribs/bosses, tight corners, or fine textures that must fill reliably with repeatable cosmetics after coating.
It’s a staple for electronics/telecom housings, lighting enclosures, appliance frames, automotive interior brackets, small gearbox/actuator covers, and other medium-strength components where castability and appearance outrank maximum ductility.
Use ADC12 when you need:
- Strong thin-wall fill (≈1.5–2.5 mm typical; local ~1.2 mm possible with tuned gating/vacuum).
- Complex geometry replication (logos, vents, fine fins).
- Predictable paint/powder appearance after proper pretreatment.
Consider other alloys when:
- You need higher elongation/corrosion resistance outdoors (often A380 or design/finish changes).
- You require post-cast heat strengthening (HPDC porosity makes T6 impractical).
ADC12 chemical composition
Typical production ranges (mass %). Always purchase to the exact standard/revision and require melt certificates.
| Element | Range (wt. %) | Role in casting/performance |
|---|---|---|
| Si | ~9.0–12.0 | Drives fluidity, thin-wall fill; higher Si lowers solidification shrinkage but can reduce elongation. |
| Cu | ~1.5–3.5 | Boosts strength/hardness; excessive Cu can reduce corrosion resistance. |
| Fe | ~0.6–1.3 | Controls die soldering; too high may embrittle/elevate porosity. |
| Mn | ≤0.5 | Balances Fe phase; helps limit soldering. |
| Mg | ≤0.3 | Small additions for strength/ageing response; affects anodizing behavior. |
| Ni, Zn, Sn | ≤0.5 each (typ.) | Trace controls; excessive Ni lowers ductility. |
| Al | Balance | — |
Supplier practice varies by region; verify chemistry on the spectrochemical report for every heat/lot.
ADC12 mechanical properties
Representative ranges for HPDC parts; actual values depend on wall, gate design, vacuum level, and melt quality.
| Property | Typical Range | Notes |
|---|---|---|
| Ultimate tensile strength | ~260–330 MPa | Thicker, sound sections trend higher. |
| Yield strength (0.2%) | ~150–190 MPa | Sensitive to porosity/solidification rate. |
| Elongation | ~1.5–3.5 % | Thinner walls & higher Fe/Ni push lower end. |
| Brinell hardness (HBW) | ~80–95 | Correlates with Cu/Mg and cooling. |
Physical properties & casting behavior of ADC12
| Property | Typical value / range | Design implication |
|---|---|---|
| Density | ~2.72–2.74 g/cm³ | Mass estimates for housings/covers. |
| Thermal conductivity | ~90–120 W/m·K | Useful for lighting/electronics. |
| Electrical conductivity | ~22–30 % IACS | Adequate for shielding enclosures. |
| CTE (20–100 °C) | ~21–23 µm/m·K | Consider in tight assemblies. |
| Solidus–liquidus | ~520–590 °C | Guides die/melt temperature windows. |
Casting behavior (plain-English):
ADC12 flows easily into thin, intricate features and tolerates higher gate speeds. It is prone to gas porosity if venting/vacuum are weak; well-placed overflows and vacuum assist improve pressure-tightness and cosmetics. Fe/Mn balance and lube control help prevent die soldering. With the right pretreatment, ADC12 takes paint/powder/e-coat very predictably.
What is ADC12 equivalent to in other standards?
Cross-references (verify per spec before buying):
- AA/ASTM (US): A383 (purpose-equivalent family)
- EN (EU): EN AC-46000 (AlSi9Cu3) family
- Common CN/ISO notations: AlSi9Cu3-family grades
These are equivalents by intent, not identical chemistries. On POs, specify your base standard, allow named equivalents, and require melt certs plus any mechanical/finish tests that matter to you.
ADC12 vs A380: which alloy is better for thin walls and complex parts?
| Factor | ADC12 | A380 | What it means |
|---|---|---|---|
| Fluidity / thin-wall fill | Higher | High | ADC12 reproduces fine ribs/vents with fewer short-shots. |
| Hot-cracking tendency | Lower | Low | Better for tight corners & long flow. |
| Pressure-tight potential | Medium (good with vacuum) | Medium–High | Both may need impregnation for zero-leak specs. |
| Ductility | Medium | Slightly higher | If elongation matters, A380 may edge out. |
| Cosmetics after coating | Very good | Very good | ADC12 often shows cleaner knit lines in thin sections. |
| Availability | Very common (APAC/EU) | Very common (global) | Choose by geometry + supplier experience. |
Rule of thumb: ADC12 for thin/complex parts and crisp detail; A380 when geometry is moderate and you want the broadest strength/cost balance.
Can ADC12 be heat-treated or anodized/painted effectively?
HPDC ADC12 is usually used as-cast. Full T6 heat treatment is not typical (porosity can blister and dimensions can drift). A light stabilize/age cycle is sometimes used to improve machining/flatness stability—validate on first articles.
Finishing reality
- Powder/paint/e-coat: Most predictable appearance & corrosion performance with proper pretreatment (clean → light etch → zirconium or phosphate conversion).
- Anodizing: Possible but tends to be grey/matte on die-cast surfaces; run trials if appearance is critical.
- Plating: Feasible with tight pretreatment control (clean → zincate/strike → build); qualify on production-like coupons and geometry.
How do you design ADC12 parts?
| Feature | Starting guideline | Why it helps |
|---|---|---|
| Wall thickness | 1.5–2.5 mm (local ~1.2 mm possible) | Matches ADC12 fluidity without freeze-off. |
| Ribs | 0.6–0.8× wall; base fillet ≥0.25× wall | Reduces sink/hot-spot; fills reliably. |
| Bosses | OD ≥2.0× screw size; core draft ≥1° | Prevents tearing at ejection; supports threads. |
| Draft | 1–2° cavity; 0.5–1° cores (add for texture) | Protects cosmetics; eases release. |
| Fillets | Internal ≥0.5× wall; external generous | Lowers stress & porosity risk. |
| Gating/overflows | Gate into thickest region; generous overflows at knit lines | Purges gas and improves cosmetics. |
Parting line & ejection: Place on non-cosmetic faces; avoid thin webs as primary datums.
Texture effects: Add 0.5–1.0° extra draft for medium–heavy textures.
For minimum wall thickness deep-dive guidance, see your dedicated page “What’s the Minimum Wall Thickness for ADC12 Die-Cast Parts?” and link it here.
Machining, sealing & dimensional control for ADC12
ADC12 machines well with sharp carbide, positive rake, and flood coolant. On thin webs/bosses, use multiple light passes to avoid edge crumble and spring-back. For threads, cut or form depends on wall and load; thread inserts are best for high clamp/repeat assembly.
Leak-critical parts
- Prefer vacuum HPDC, balanced flow, and clean venting.
- Define the leak test method & limit (air-under-water or mass-flow) in your PO.
- For zero-leak specs, budget impregnation (targeted if CT shows pore connectivity near sealing faces).
Dimensional stability
- Uniform stock removal; avoid localized heavy cuts.
- Rigid fixturing that minimizes clamp distortion.
- Optional stabilize/age step for tight flatness or positional tolerances.
How do we verify ADC12 material and performance?
| QC item | Method / note | Purpose |
|---|---|---|
| Chemistry | Spectrometer per heat/ladle | Confirms ADC12 window & trace control. |
| Melt quality | Degassing/H-indicator, inclusion checks | Reduces gas porosity/defects. |
| CT/X-ray | FAI + per control plan | Verifies porosity class/critical zones. |
| Mechanical | Tensile (cut-out or coupons), HB | Confirms strength window on PPAP/FAI. |
| Dimensions | CMM + functional gages (GR&R) | Validates GD&T datums and features. |
| Finish tests | Adhesion/salt-spray (if required) | Confirms coating robustness. |
| Leak test | Air or mass-flow with limit | Ensures pressure-tightness where needed. |
Common defects & quick fixes
- Gas porosity → stronger vacuum, larger overflows, shorter flow length, cleaner melt.
- Cold shuts/knit lines → raise local metal temp, move/resize gates, add fillets.
- Soldering → tune Fe/Mn, adjust die temperature/lube, polish hotspots.
Applications & part examples
| Industry | Typical components | Why ADC12 works |
|---|---|---|
| Electronics/Telecom | Small housings, connector bodies, heat-sink covers | Thin-wall fill + decent thermal path. |
| Lighting | LED housings, bezels, driver covers | Fins & vents replicate cleanly; coats well. |
| Automotive interior | Brackets, carriers, actuator covers | Dense ribs/boss arrays with good cosmetics. |
| Appliances/Tools | Gearbox covers, frames, handles | Good machinability and repeatability. |
| General industrial | Meter bodies, valve/actuator shells | Moderate pressure-tightness with vacuum/impregnation. |
Buyer’s guide: does ADC12 reduce total cost vs alternatives?
Where ADC12 saves money
- Higher yield on thin/complex parts (fewer short-shots).
- Less cosmetic rework before coating.
- Potential weight reduction without extra operations.
Where cost can rise
- Leak-critical parts (impregnation/extra QC).
- Heavy machining on very thin sections (fixture time, multiple light passes).
What we need to quote accurately
- 3D CAD (STEP/Parasolid) + 2D with GD&T
- Annual volume & target piece price band
- Cosmetic faces & finish (powder/paint/e-coat/anodize)
- Environment (indoor/outdoor, chemicals, salt/fog)
- Leak and mechanical targets (if any)
ADC12 FAQ
What is ADC12 equivalent to?
A383 (AA/ASTM) and EN AC-46000 (AlSi9Cu3) are common cross-references; confirm chemistry/tests on the contract.
Is ADC12 stronger than A380?
Nominal strengths overlap; A380 can show slightly higher elongation. For thin/complex fills and crisp detail, ADC12 is often preferred.
Can ADC12 be anodized?
Possible but typically grey/matte on HPDC surfaces; powder/e-coat are more predictable for cosmetics/corrosion.
What density and conductivity should I use?
Use 2.73 g/cm³ for mass, ~90–120 W/m·K for thermal calcs, ~22–30 % IACS for electrical (verify with your supplier’s data).
Is ADC12 suitable for pressure-tight parts?
Yes—with vacuum die casting, robust venting/overflows, and, for strict leak limits, targeted impregnation.
What minimum wall thickness can ADC12 achieve?
Typical designs use 1.5–2.5 mm; ~1.2 mm is achievable locally with tuned gating, short flow length, and warm dies (see our dedicated minimum-wall article).
Looking for an aluminum die-casting supplier for ADC12 parts?
Yongzhu Casting provides fast, engineering-driven quotes and manufacturability feedback—then delivers production with stable quality.
- Processes: High-pressure die casting (vacuum optional), CNC machining, deburr, powder/paint/e-coat
- Presses: 800–2000 ton; thin-wall housings and complex brackets experience
- Quality: Spectrometer melt checks, CT/X-ray (as required), CMM, leak testing, PPAP on request
Email yongzhucasting@gmail.com with STEP files, annual volume, finish target, and any leak/mechanical requirements.
We’ll return a concise DFM memo (draft/ribs/bosses/gating suggestions) and a clear quotation.
