Die casting process parameters are the “invisible hands” that control casting quality, eficiência de produção, and cost—yet many engineers struggle with balancing parameters like pressure, velocidade, tempo, e temperatura. A wrong injection pressure may cause porosity; an improper mold temperature could lead to poor surface finish. This article breaks down the four core parameter categories, their working principles, optimization strategies, and real-world applications—helping you master parameter setting for flawless castings.
1. Pressure Parameters: The “Driving Force” for Dense Castings
Os parâmetros de pressão determinam quão bem o metal fundido preenche a cavidade do molde e forma uma estrutura compacta. Abaixo está um Estrutura de pontuação total explicando as principais métricas de pressão, fórmulas, e regras de aplicação:
1.1 Key Pressure Metrics & Definitions
| Métrica | Definição | Função central |
| Força de injeção | Força gerada pelo cilindro da máquina de fundição para empurrar o punção (empurra o metal fundido para dentro da cavidade). | Fornece o poder para superar a resistência ao fluxo de metal. |
| Pressão de injeção | Dynamic pressure of molten metal during injection (monitored via pressure gauges). | Affects metal flow speed and cavity filling completeness. |
| Specific Injection Pressure | Pressure per unit area acting on molten metal (critical for casting density). | Directly impacts casting compactness—higher values reduce porosity. |
1.2 Specific Injection Pressure: Formula & Otimização
The specific injection pressure is calculated using the formula:
Specific Pressure (MPA) = Injection Force (N) ÷ (π × Punch Diameter² (m²) ÷ 4)
Optimization rules (based on casting complexity):
- Complex/Thin-Walled Parts (Por exemplo, aluminum alloy phone casings, espessura da parede <1.5milímetros): Require high specific pressure (50-80 MPA) to improve filling capacity and avoid incomplete contours.
- Simple/Thick-Walled Parts (Por exemplo, aluminum alloy brackets, wall thickness >5mm): Use lower specific pressure (30-50 MPA) to prevent mold damage and reduce energy consumption.
Nota crítica: Adjust specific pressure by either changing the injection force or replacing the punch (larger punch diameter = lower specific pressure for the same force).
2. Speed Parameters: Balancing Filling Efficiency & Qualidade da superfície
Speed parameters control how fast molten metal flows into the mold—too fast causes turbulence (porosidade); too slow leads to premature solidification (preenchimento incompleto). Abaixo está um comparison-based breakdown of key speed metrics:
2.1 Injection Speed vs. Inner Gate Velocity
| Speed Type | Definição | Faixa típica | Impact on Castings | Dicas de otimização |
| Injection Speed | Linear speed of the punch pushing molten metal in the pressure chamber. | 0.1~0.8 m/s | Determines overall filling time; affects metal flow stability. | Choose based on pressure chamber fullness (ratio of metal volume to pressure chamber volume): – Fullness >80%: Use lower speed (0.1~0.3 m/s) to avoid splashing. – Fullness <50%: Increase speed (0.5~0.8 m/s) to prevent solidification. |
| Inner Gate Velocity | Linear speed of molten metal entering the mold cavity through the inner sprue. | 15~50 m/s (liga de alumínio) | Directly affects surface finish, força, e plasticidade. | Match to casting wall thickness: – Paredes finas (<2milímetros): Higher velocity (35~50 m/s) to fill quickly. – Paredes grossas (>4milímetros): Lower velocity (15~30m/s) to reduce turbulence. |
Exemplo do mundo real: For aluminum alloy automotive sensor housings (thin-walled, complexo), set inner gate velocity to 40~45 m/s—this ensures smooth flow and avoids air entrapment (a major cause of leakage).
3. Time Parameters: Controlling Solidification for Stable Quality
Time parameters manage the “waiting period” of molten metal in the mold—from filling to ejection. Incorrect timing leads to defects like shrinkage or deformation. Abaixo está um linear, time-axis breakdown of key time metrics:
3.1 Core Time Metrics for Aluminum Alloy Die Castings
| Time Metric | Definição | Faixa típica | Influencing Factors | Optimization Rules |
| Filling Time | Time for molten metal to fill the entire mold cavity. | 0.01~0.1 seconds | – Higher pouring temperature = longer filling time. – Higher mold temperature = longer filling time. – Thicker walls (far from inner gate) = longer filling time. | Para peças de parede fina: Shorten to 0.01~0.03 seconds to prevent solidification. Para peças com paredes espessas: Extend to 0.05~0.1 seconds to ensure even filling. |
| Tempo de espera | Tempo para o metal fundido solidificar sob pressão após o preenchimento da cavidade. | 1~2 segundos (partes finas); 3~7 segundos (partes grossas) | – Faixa de cristalização de liga (faixa mais ampla = maior tempo de retenção). – Espessura da parede de fundição (mais grosso = maior tempo de espera). | Certifique-se de que o tempo de retenção seja 1,2 a 1,5 vezes o tempo de solidificação da peça mais espessa - evita furos de contração. |
| Tempo de retenção de molde | Tempo desde o final da pressão de retenção até a ejeção do lançamento. | 5~25 segundos | – Propriedades da liga (alto ponto de fusão = mais tempo). – Espessura da parede de fundição (mais grosso = mais tempo). | Eject when the casting temperature drops to 300~400°C (liga de alumínio)—too early causes deformation; too late increases ejection force. |
4. Temperature Parameters: Avoiding Overheating & Undercooling
Temperature parameters control the “thermal balance” of the die-casting system—molten metal temperature (pouring temperature) and mold temperature directly affect metal flow and solidification. Abaixo está um cause-effect structure explaining key temperature metrics:
4.1 Pouring Temperature: The “Thermal Energy” for Flow
- Typical Range for Aluminum Alloy: 650°C~720°C
- Princípios principais:
- Minimize overheating (exceeding 720°C): Causes grain coarsening (reduces casting strength) and increases mold wear.
- Avoid undercooling (below 650°C): Reduces metal fluidity, leading to incomplete filling and cold shuts (seams where molten metal streams don’t fuse).
- Optimization for Special Parts:
- Thin-walled/Complex Parts (Por exemplo, aluminum alloy heat sinks): Increase to 700°C~720°C to improve flow.
- Thick-Walled Parts (Por exemplo, aluminum alloy engine brackets): Lower to 650°C~680°C to prevent shrinkage.
4.2 Temperatura do molde: O “amortecedor térmico” para qualidade
- Typical Range for Aluminum Alloy: 200°C~280°C
- Control Requirements:
- Estabilidade: Maintain temperature within ±25°C—uneven mold temperature causes warping (Por exemplo, one side of the casting is hotter, leading to uneven shrinkage).
- Part-Specific Adjustments:
- Thin-Walled/Complex Parts: Higher mold temperature (250°C~280°C) to slow solidification and improve surface finish.
- Thick-Walled Parts: Temperatura de molde mais baixa (200°C~230°C) to accelerate cooling and reduce cycle time.
Practical Tip: Use mold temperature controllers (with water or oil circulation) to monitor and adjust temperature in real time—this reduces temperature fluctuations by 40%.
5. 4-Lista de verificação de otimização de parâmetros de etapa
To avoid trial-and-error, siga isto practical checklist for parameter setting:
- Analyze Casting Requirements: Define key targets (Por exemplo, surface finish Ra <3.2μm, no porosity) and part features (espessura da parede, complexidade).
- Set Baseline Parameters: Use typical ranges (Por exemplo, liga de alumínio: injection speed 0.3~0.5 m/s, mold temperature 220°C~250°C) as starting points.
- Teste & Ajustar: Run 50~100 trial castings, inspect for defects:
- Porosity → Increase specific pressure or reduce injection speed.
- Cold Shuts → Raise pouring temperature or mold temperature.
- Warping → Stabilize mold temperature (reduce ± fluctuation).
- Document & Standardize: Record optimized parameters (Por exemplo, “Aluminum alloy phone casing: specific pressure 65 MPA, inner gate velocity 42 m/s”) for future batches.
Perspectiva da Yigu Technology sobre os parâmetros do processo de fundição sob pressão
Na tecnologia Yigu, acreditamos parameter synergy is more critical than individual optimization. Many clients fix one defect (Por exemplo, porosity via higher pressure) only to create another (Por exemplo, dano ao molde). We use a “data-driven optimization” approach: 1) Collect real-time parameter data (via sensors) during trial runs; 2) Use AI to analyze correlations (Por exemplo, how mold temperature and holding time together affect shrinkage); 3) Recommend balanced parameters (Por exemplo, for aluminum alloy automotive parts: 680°C pouring temp, 240°C mold temp, 45 MPa specific pressure) that meet both quality and efficiency goals. Para pedidos de pequenos lotes, we also offer rapid parameter testing to cut setup time by 30%.
Perguntas frequentes (Perguntas frequentes)
- P: If my aluminum alloy casting has incomplete contours (missing small features), should I increase injection speed or specific pressure first?
UM: First increase specific pressure (by 10~15 MPa). Incomplete contours often result from insufficient force to push metal into tiny cavities—higher pressure improves filling. If contours remain incomplete, then increase inner gate velocity (by 5~10 m/s) to speed up flow.
- P: Why does my casting have surface cracks even with correct temperature parameters?
UM: Verificar mold retention time. Cracks usually occur when the casting is ejected too early (not fully solidified) or too late (overly rigid, prone to stress during ejection). For aluminum alloy parts, adjust retention time to 10~15 seconds (partes grossas) or 5~8 seconds (partes finas) and verify.
- P: Can I use the same pressure and speed parameters for different aluminum alloy grades (Por exemplo, 6061 vs.. ADC12)?
UM: Não. ADC12 (die-casting-specific alloy) has better fluidity than 6061—so use lower specific pressure (30~50 MPa for ADC12 vs. 40~60 MPa for 6061) and lower inner gate velocity (25~40 m/s for ADC12 vs. 35~50 m/s for 6061) to avoid turbulence.