Semi-solid die casting and ordinary die casting are two core technologies in metal forming, each optimized for different production needs. While both inject metal into molds to create parts, their fundamental differences in metal state, process control, and performance make them suited for distinct applications—from high-strength automotive components to low-cost consumer goods. Но что именно выделяет их? How do these differences impact cost, эффективность, и качество частично? And how do you choose the right technology for your project? This article answers these questions with detailed comparisons and actionable insights.
1. Основные определения & Principles: 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.
А. Ordinary Die Casting
- Metal State: Использование fully molten liquid metal (НАПРИМЕР., aluminum alloy heated to ≥650°C). The metal flows like water, with low viscosity and Newtonian fluid characteristics.
- Core Mechanism: Relies on high speed and high pressure (typical pressure: 100–150MPa) to force liquid metal to fill complex mold cavities quickly (often in <0.1 секунды). 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 и stomata (пористость), especially in thick-walled areas.
Беременный. Полутвердое литье под давлением
- Metal State: Использование semi-solid slurry or billets—a solid-liquid coexistence state (solid fraction: 50–90%). The metal behaves like “toothpaste”: толстый, viscous, and non-Newtonian (its flowability improves with shear force).
- Core Mechanism: Leverages the high viscosity and non-dendritic microstructure of semi-solid metal. It fills the mold at a slower, more controlled speed (no turbulent splashing), reducing gas entrainment and defect risks.
- Microstructure Result: Spherical primary solid phase particles are evenly distributed in the liquid phase. После затвердевания, the part has fine spherical grains and a fibrous matrix, leading to better mechanical property uniformity (isotropy) and fewer defects.
2. Side-by-Side Process Comparison: Key Operational Differences
To understand how these technologies perform in practice, let’s compare their process steps, параметры, and constraints in a clear table:
| Process Aspect | Ordinary Die Casting | Полутвердое литье под давлением |
| Metal Pretreatment | Простой: Melt metal directly to a liquid state; no special preparation. | Сложный: Requires semi-solid slurry/billet production (via mechanical mixing, электромагнитное перемешивание, or low-temperature deposition). |
| Filling Characteristics | High-speed jetting (часто >5РС); prone to eddy currents and metal splashing. | Медленный, smooth filling (обычно <2РС); high viscosity prevents turbulence. |
| Typical Operating Pressure | 100–150MPa (needs high pressure to overcome liquid metal inertia). | 60–100MPa (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 (НАПРИМЕР., water channels every 20mm). | Низкий (semi-solid metal has less latent heat to release); cooling system can be simpler. |
| Solidification Shrinkage | Большой (liquid metal contracts significantly during cooling); easy to form shrinkage defects. | Меньше (solid phase already dominates the metal, reducing total contraction). |
| Минимальная толщина стенки | Capable of ultra-thin walls (до 0,5 мм); ideal for lightweight parts. | Ограничен (typical minimum: ≥1mm); semi-solid metal’s viscosity struggles to fill tiny gaps. |
| Время цикла | Extremely fast (<30 секунды за часть); no extra steps for slurry preparation. | Дольше (45–90 seconds per part); includes time for slurry production or billet reheating. |
3. Производительность & Приложение: Which Shines Where?
The process differences directly translate to distinct performance advantages—making each technology better suited for specific part types.
А. Performance Comparison
| Показатель производительности | Ordinary Die Casting | Полутвердое литье под давлением |
| Предел прочности | Ниже (НАПРИМЕР., 200–250MPa for aluminum alloys). | Выше (15–30% increase; НАПРИМЕР., 230–325MPa for aluminum alloys). |
| Удлинение | Низкий (typically 2–5% for aluminum parts). | Doubled (4–10% for aluminum parts); spherical grains hinder crack propagation. |
| Скорость дефекта | Высокий (porosity and shrinkage are common; Скорость лома: 5–12%). | Низкий (greatly reduces stomata and shrinkage; Скорость лома: 1–3%). |
| Heat Treatment Stability | Бедный (heat treatment often expands existing pores, causing deformation). | Отличный (uniform microstructure resists deformation; suitable for T6 heat treatment). |
| Стоимость за часть | Низкий (\(0.3- )1 per kg for aluminum parts); mature equipment and simple process. | Высокий (\(0.8- )2 per kg for aluminum parts); needs special slurry equipment. |
Беременный. Сценарии приложения: Choosing the Right Fit
The table below maps each technology to its ideal use cases, based on performance and cost needs:
| Part Requirement | Prefer Semi-Solid Die Casting | Prefer Ordinary Die Casting |
| Критически важные для безопасности детали | Automotive steering knuckles, тормозные суппорты (need high strength and low defects). | None—safety parts require reliability beyond ordinary die casting’s capabilities. |
| Pressure-Resistant Components | Hydraulic valve bodies, air compressor cylinders (no pores to leak under pressure). | Маленькие электрические корпуса (no pressure load; cost is key). |
| High-Toughness Needs | Motorcycle hubs, golf heads (must withstand impact without cracking). | Toy models, Простые скобки (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, Корпус потребительской электроники (высокий объем, бюджетный). |
4. Оборудование & Расходы: The Investment Tradeoff
Choosing between the two technologies also means evaluating upfront and long-term costs, driven by equipment differences.
А. Equipment Requirements
| Тип оборудования | Ordinary Die Casting | Полутвердое литье под давлением |
| Core Machine | Standard die casting machine (НАПРИМЕР., 200–300-ton models); widely available. | Specialized machine with slurry feeding systems; often custom-built. |
| Pretreatment Gear | Basic melting furnace (no extra tools needed). | Slurry preparation equipment (НАПРИМЕР., electromagnetic stirrers, low-temperature deposition units). |
| Дизайн плесени | Simple molds (focus on fast cooling; no special flow controls). | Molds with optimized gating (to handle viscous semi-solid metal; may need larger runners). |
Беременный. Стоимость разбивки (Aluminum Alloy Parts, 10,000-Part Batch)
| Категория затрат | Ordinary Die Casting | Полутвердое литье под давлением |
| Equipment Investment | \(50,000- )100,000 (standard machine + печь). | \(150,000- )300,000 (specialized machine + slurry gear). |
| Стоимость плесени | \(5,000- )15,000 (Простой дизайн, no complex features). | \(10,000- )25,000 (optimized for semi-solid flow). |
| Per-Part Material Cost | \(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: Будущие тенденции
Both technologies are evolving to address their limitations—with semi-solid casting leading in innovation for high-performance needs.
А. 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 (легче алюминия) 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), Согласно целям устойчивости.
Беременный. Ordinary Die Casting Improvements
- Defect Reduction: Adding vacuum systems to remove gas during filling reduces porosity by 30–40%.
- Автоматизация: 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
В Yigu Technology, we see semi-solid and ordinary die casting as complementary tools—not competitors. For automotive clients needing safety parts (НАПРИМЕР., тормозные суппорты), 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 стандарты. For consumer electronics clients, our optimized ordinary die casting lines (с вакуумной дегазацией) 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 (НАПРИМЕР., integrated die-cast automotive bodies). Это балансирует производительность и стоимость., 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.
Часто задаваемые вопросы
- Can semi-solid die casting be used for ultra-thin parts (НАПРИМЕР., 0.5ММ стены)?
No—semi-solid metal’s high viscosity makes it hard to fill tiny gaps. Ультратонкие части (≤0.8mm) are better suited for ordinary die casting, which uses low-viscosity liquid metal to reach narrow cavities. For parts with mixed thicknesses (НАПРИМЕР., a 1mm main body + 0.6мм ребра), 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, давление, or heat (НАПРИМЕР., Гидравлические фитинги), yes—semi-solid casting’s durability reduces long-term maintenance costs. If it’s a non-load decorative part (НАПРИМЕР., lamp shades), ordinary die casting is more cost-effective. We recommend calculating the “total cost of ownership” (не только стоимость за деталь) 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. Термическая обработка (НАПРИМЕР., T6) often expands these pores, causing deformation or even cracking. Semi-solid casting parts, with their uniform spherical grains, can handle heat treatment without issues, but ordinary parts typically cannot achieve the same strength gains. For heat-treated parts, semi-solid casting is the more reliable choice.