Semi-solid die casting and ordinary die casting are two core technologies in metal forming, jeweils für unterschiedliche Produktionsanforderungen optimiert. While both inject metal into molds to create parts, their fundamental differences in metal state, Prozesskontrolle, and performance make them suited for distinct applications—from high-strength automotive components to low-cost consumer goods. Aber was genau unterscheidet sie? How do these differences impact cost, Effizienz, und Teilqualität? And how do you choose the right technology for your project? This article answers these questions with detailed comparisons and actionable insights.
1. Kerndefinitionen & Prinzipien: The Fundamental Gap
The biggest difference between the two technologies lies in the state of the metal during processing, which shapes their entire working mechanisms.
A. Ordinary Die Casting
- Metal State: Verwendung fully molten liquid metal (Z.B., aluminum alloy heated to ≥650°C). The metal flows like water, with low viscosity and Newtonian fluid characteristics.
- Kernmechanismus: Verlässt sich auf high speed and high pressure (typical pressure: 100–150MPa) to force liquid metal to fill complex mold cavities quickly (often in <0.1 Sekunden). Rapid cooling in the mold then solidifies the metal into the desired shape.
- Microstructure Result: Due to fast cooling, the final part has fine but unevenly distributed grains, plus a large number of eutectic structures. This often leads to defects like shrinkage holes Und stomata (Porosität), especially in thick-walled areas.
B. Halbfester Druckguss
- Metal State: Verwendung semi-solid slurry or billets—a solid-liquid coexistence state (solid fraction: 50–90 %). The metal behaves like “toothpaste”: dick, viscous, and non-Newtonian (its flowability improves with shear force).
- Kernmechanismus: Leverages the high viscosity and non-dendritic microstructure of semi-solid metal. It fills the mold at a slower, more controlled speed (kein turbulentes Spritzen), reducing gas entrainment and defect risks.
- Microstructure Result: Spherical primary solid phase particles are evenly distributed in the liquid phase. Nach dem Erstarren, the part has fine spherical grains and a fibrous matrix, leading to better mechanical property uniformity (isotropy) and fewer defects.
2. Paralleler Prozessvergleich: Wichtige betriebliche Unterschiede
To understand how these technologies perform in practice, let’s compare their process steps, Parameter, and constraints in a clear table:
| Prozessaspekt | Ordinary Die Casting | Halbfester Druckguss |
| Metal Pretreatment | Einfach: Melt metal directly to a liquid state; no special preparation. | Komplex: Requires semi-solid slurry/billet production (via mechanical mixing, elektromagnetisches Rühren, or low-temperature deposition). |
| Filling Characteristics | High-speed jetting (oft >5MS); prone to eddy currents and metal splashing. | Langsam, smooth filling (Typischerweise <2MS); high viscosity prevents turbulence. |
| Typical Operating Pressure | 100–150MPa (needs high pressure to overcome liquid metal inertia). | 60–100 MPa (lower pressure due to reduced flow resistance of semi-solid metal). |
| Mold Heat Load | Extremely high (liquid metal releases large latent heat); requires a powerful cooling system (Z.B., water channels every 20mm). | Niedrig (semi-solid metal has less latent heat to release); cooling system can be simpler. |
| Erstarrungsschrumpfung | Groß (liquid metal contracts significantly during cooling); easy to form shrinkage defects. | Kleiner (solid phase already dominates the metal, reducing total contraction). |
| Mindestwanddicke | Capable of ultra-thin walls (bis 0,5 mm); ideal for lightweight parts. | Beschränkt (typical minimum: ≥1mm); semi-solid metal’s viscosity struggles to fill tiny gaps. |
| Zykluszeit | Extremely fast (<30 Sekunden pro Teil); no extra steps for slurry preparation. | Länger (45–90 seconds per part); includes time for slurry production or billet reheating. |
3. Leistung & Anwendung: Which Shines Where?
The process differences directly translate to distinct performance advantages—making each technology better suited for specific part types.
A. Performance Comparison
| Leistungsmetrik | Ordinary Die Casting | Halbfester Druckguss |
| Zugfestigkeit | Untere (Z.B., 200–250MPa for aluminum alloys). | Höher (15–30% increase; Z.B., 230–325MPa for aluminum alloys). |
| Verlängerung | Niedrig (typically 2–5% for aluminum parts). | Doubled (4–10% for aluminum parts); spherical grains hinder crack propagation. |
| Defektrate | Hoch (porosity and shrinkage are common; Schrottrate: 5–12 %). | Niedrig (greatly reduces stomata and shrinkage; Schrottrate: 1–3%). |
| Heat Treatment Stability | Arm (heat treatment often expands existing pores, causing deformation). | Exzellent (uniform microstructure resists deformation; suitable for T6 heat treatment). |
| Kosten pro Teil | Niedrig (\(0.3- )1 per kg for aluminum parts); mature equipment and simple process. | Hoch (\(0.8- )2 per kg for aluminum parts); needs special slurry equipment. |
B. Anwendungsszenarien: Choosing the Right Fit
The table below maps each technology to its ideal use cases, based on performance and cost needs:
| Teileanforderung | Prefer Semi-Solid Die Casting | Prefer Ordinary Die Casting |
| Sicherheitskritische Teile | Automotive steering knuckles, Bremssättel (need high strength and low defects). | None—safety parts require reliability beyond ordinary die casting’s capabilities. |
| Pressure-Resistant Components | Hydraulische Ventilkörper, air compressor cylinders (no pores to leak under pressure). | Kleine elektrische Gehäuse (no pressure load; cost is key). |
| High-Toughness Needs | Motorcycle hubs, golf heads (must withstand impact without cracking). | Toy models, Einfache Klammern (low impact risk). |
| High-Temperature Service | Engine head brackets (stable microstructure resists heat deformation). | Cookware handles (low heat exposure; cost matters more). |
| Ultra-Thin or High-Volume Parts | None—struggles with thin walls and slow cycle times. | Home appliance shells, lamp frames, Unterhaltungselektronikgehäuse (Hochvolumen, niedrige Kosten). |
4. Ausrüstung & Kosten: The Investment Tradeoff
Choosing between the two technologies also means evaluating upfront and long-term costs, driven by equipment differences.
A. Ausrüstungsanforderungen
| Gerätetyp | Ordinary Die Casting | Halbfester Druckguss |
| Core Machine | Standard die casting machine (Z.B., 200–300-ton models); weit verbreitet. | Specialized machine with slurry feeding systems; often custom-built. |
| Pretreatment Gear | Basic melting furnace (no extra tools needed). | Slurry preparation equipment (Z.B., electromagnetic stirrers, low-temperature deposition units). |
| Schimmeldesign | Einfache Formen (focus on fast cooling; no special flow controls). | Molds with optimized gating (to handle viscous semi-solid metal; may need larger runners). |
B. Kostenaufschlüsselung (Aluminum Alloy Parts, 10,000-Part Batch)
| Kostenkategorie | Ordinary Die Casting | Halbfester Druckguss |
| Ausrüstungsinvestitionen | \(50,000- )100,000 (standard machine + Ofen). | \(150,000- )300,000 (specialized machine + slurry gear). |
| Schimmelpilze | \(5,000- )15,000 (Einfaches Design, no complex features). | \(10,000- )25,000 (optimized for semi-solid flow). |
| Materialkosten pro Teil | \(0.3- )0.5 (higher waste rate: 10–15% due to defects). | \(0.4- )0.6 (lower waste rate: 3–5% fewer defects). |
| Total Batch Cost | ~ (8,000- )17,500 | ~ (25,000- )51,000 |
5. Technological Evolution: Zukünftige Trends
Both technologies are evolving to address their limitations—with semi-solid casting leading in innovation for high-performance needs.
A. Semi-Solid Die Casting Innovations
- Intelligent Slurry Control: Real-time electromagnetic stirring devices now monitor and adjust the solid fraction (to ±2%) during slurry production, ensuring consistent metal quality.
- Composite Molding: Combining semi-solid casting with squeeze casting further increases part density (reducing remaining porosity to <0.5%).
- New Material Adaptation: Expanding to magnesium alloys (leichter als Aluminium) and high-entropy alloys (superior heat resistance), opening doors for aerospace applications.
- Green Manufacturing: Uses ~20% less energy than ordinary die casting (no need to fully melt metal), Ausrichtung auf Nachhaltigkeitsziele.
B. Ordinary Die Casting Improvements
- Defect Reduction: Adding vacuum systems to remove gas during filling reduces porosity by 30–40%.
- Automatisierung: Fully automated lines (with robotic part removal) cut labor costs by 50% and boost cycle time consistency.
6. Yigu Technology’s Perspective on the Two Technologies
Bei Yigu Technology, we see semi-solid and ordinary die casting as complementary tools—not competitors. For automotive clients needing safety parts (Z.B., Bremssättel), our semi-solid die casting solutions (equipped with real-time slurry monitoring) deliver tensile strength gains of 25% and scrap rates below 2%, meeting IATF 16949 Standards. Für Kunden der Unterhaltungselektronik, our optimized ordinary die casting lines (mit Vakuumentgasung) reduce costs by 30% while keeping defects low enough for non-load parts.
We’re investing in “hybrid manufacturing” models: using semi-solid casting for high-strength main structures and ordinary casting for secondary features (Z.B., integrated die-cast automotive bodies). This balances performance and cost, helping clients avoid overpaying for technology they don’t need. Our goal is to tailor each solution to the part’s actual requirements—no one-size-fits-all.
FAQ
- Can semi-solid die casting be used for ultra-thin parts (Z.B., 0.5Mm Wände)?
No—semi-solid metal’s high viscosity makes it hard to fill tiny gaps. Ultradünne Teile (≤0.8mm) are better suited for ordinary die casting, which uses low-viscosity liquid metal to reach narrow cavities. For parts with mixed thicknesses (Z.B., a 1mm main body + 0.6mm Rippen), consider hybrid designs: use semi-solid casting for the main body and post-machine the thin ribs.
- Is semi-solid die casting worth the higher cost for non-safety parts?
It depends on the part’s function. If the part needs to withstand impact, Druck, or heat (Z.B., Hydraulische Ausstattung), yes—semi-solid casting’s durability reduces long-term maintenance costs. If it’s a non-load decorative part (Z.B., Lampenschirme), ordinary die casting is more cost-effective. We recommend calculating the “total cost of ownership” (not just per-part cost) to decide.
- Can ordinary die casting parts be heat-treated to match semi-solid casting performance?
Rarely—ordinary die casting parts have hidden pores and uneven microstructures. Wärmebehandlung (Z.B., T6) often expands these pores, causing deformation or even cracking. Semi-solid casting parts, mit ihren gleichmäßigen kugelförmigen Körnern, kann die Wärmebehandlung problemlos bewältigen, Mit gewöhnlichen Teilen lässt sich jedoch in der Regel nicht derselbe Festigkeitsgewinn erzielen. Für wärmebehandelte Teile, Halbfester Guss ist die zuverlässigere Wahl.