Squeeze Casting

Process Definition & Working Principle

Squeeze casting, also historically referenced as liquid metal forging, is an advanced hybrid manufacturing process that bridges the operational divide between casting and forging. It integrates the near-net-shape capability of permanent mold casting with the superior mechanical density and grain refinement of hot forging. The process was engineered to systematically eliminate gas and shrinkage porosity, which are the primary metallurgical defects of conventional castings.

The physical working principle is defined by a multi-stage process sequence: a precise mass of molten alloy is poured under gravity into a preheated, open lower die. Almost instantly, an upper punch or die half driven by a hydraulic ram descends, closing the die cavity. The punch then applies a high, sustained static pressure, typically ranging from $50\text{ MPa}$ to $150\text{ MPa}$ (up to $300\text{ MPa}$ for safety-critical parts), directly to the liquid metal. This consolidation pressure is maintained continuously until the phase transformation is complete.

Solidification under high pressure exerts three critical physical effects:

Kinematics, Axes, & Machine Configuration

Squeeze casting equipment is structurally configured around heavy-duty vertical hydraulic presses, typically incorporating a four-column portal frame. This architecture guarantees high structural rigidity and minimizes elastic deflection under load. The vertical alignment is critical as it permits quiescent, gravity-assisted ladle pouring of molten metal into the open lower die, eliminating the turbulence and splash defects typical of horizontal injection sleeve setups in HPDC.

The process is divided into two distinct kinematic designs: