High-Pressure Die Casting (HPDC), NADCA P-Q^2 Gating & Cold-Chamber Shot Control
Die-Casting Gate Area, Cavity Fill Time & Plunger Speed Formula
Calculate Cavity+Overflow Melt Volume (cm³), Volumetric Injection Flow Rate Q (cm³/s), Required Ingate Cross-Sectional Area A_g (mm²), and Cold-Chamber Fast-Shot Plunger Speed (m/s).
Fill a thin-wall aluminum die in 28 milliseconds at 42 m/s gate atomization—without soldering the steel die core!
Cold-chamber High-Pressure Die Casting (HPDC) of EV motor housings and structural nodes injects molten ADC12 / AlSi10Mg (`rho_melt ~= 2.50` g/cm³ liquid!) through razor-thin gates before thin-wall sections freeze prematurely ("cold shuts")! Under NADCA gating methodology, Part + Overflow Mass M_cav (g) beyond the ingate defines Cavity Melt Volume V_cav = M_cav / rho_melt (cm³), which must fill within allowable Cavity Fill Time t_fill (ms, typically 15–40 ms) at Volumetric Flow Rate Q = V_cav / (t_fill / 1,000) cm³/s! Simultaneously, Ingate Velocity v_gate must stay inside the atomized spray window (`30–55` m/s—below 30 m/s causes coarse laminar cold-laps; above 60 m/s erodes and solders H13 die steel!), fixing Required Gate Area A_gate = Q_cm3_s / v_gate_m_s (mm²) and Fast-Shot Plunger Speed v_plunger = Q_cm3_s / ((PI() / 4) * D_plunger_mm^2) m/s!
Verify on a 920 g Aluminum Gearbox Cover Cold-Chamber Shot—Part_Plus_Overflow_Mass = 920.0 g (B2), Liquid_Al_Density = 2.50 g/cm³ (B3 -> Cavity Volume = 368.00 cm³ in E2), Target_Fill_Time = 28.0 ms (B4 -> Flow Rate Q = 13,142.9 cm³/s in E3), Target_Gate_Velocity = 42.0 m/s (B5), and Shot_Sleeve_Plunger_Diameter = 70.0 mm (B6): Required Ingate Cross-Sectional Area equals 312.93 mm² (E4) driven by a Fast-Shot Plunger Velocity of 3.42 m/s (E5)!
| NADCA HPDC Gating KPI (920 g Melt @ 2.50 g/cm³, tfill=28 ms, vgate=42 m/s, Dp=70 mm) | Formula | Verified Output |
|---|---|---|
| Cavity + Overflow Melt Vol (cm³) | Part_Overflow_Mass_g / Melt_Dens_g_cm3 | 368.00 cm³ |
| Cavity Fill Flow Rate Q (cm³/s) | Melt_Volume_cm3 / (Fill_Time_ms / 1000) | 13,142.9 cm³/s (20,444.4 @ 18 ms) |
| Required Ingate Area Ag (mm²) | Flow_Rate_cm3_s / Target_Gate_Vel_m_s | 312.93 mm² (486.77 mm² @ 18 ms!) |
| Fast-Shot Plunger Speed (m/s) | Flow_cm3_s / ((PI()/4) * Plunger_D_mm^2) | 3.42 m/s (5.31 m/s @ 18 ms) |
NADCA Continuity Gate Area & Cold-Chamber Fast-Shot Velocity Formula
Validate Mass > 0, Liquid_Density in [1.5, 8.5] g/cm³, Fill_Time in [5, 200] ms, Gate_Velocity in [20, 65] m/s, and Plunger_Diameter > 20 mm!
=LET(ms_g, B2, rh_m, B3, tf_m, B4, vg_s, B5, dp_m, B6, IF(OR(ms_g <= 0, rh_m < 1.5, rh_m > 8.5, tf_m < 5, tf_m > 200, vg_s < 20, vg_s > 65, dp_m <= 20), "Invalid HPDC Input", LET(vc_m, ms_g / rh_m, qf_l, vc_m / (tf_m / 1000), ap_l, (PI() / 4) * (dp_m ^ 2), ROUND(qf_l / ap_l, 2))))Ultra-Thin 2.0 mm Rib 18-Millisecond Fill Upgrade Check (Set Fill Time = 18.0 ms)
Thin ribs down to 2.0 mm requiring faster cavity fill t_fill B4 = 18.0 ms while holding Gate_Velocity at 42.0 m/s to prevent H13 die soldering: Flow Rate E3 surges to 20,444.4 cm³/s, Gate Area E4 must widen to 486.77 mm², and Shot Plunger Speed E5 climbs to 5.31 m/s!
=IF(ISTEXT(E5), E5, ROUND(((B2 / B3) / (B4 / 1000)) / B5, 2))Try the example
Use the original values or change them to test your understanding.