The main differences between high-pressure die casting and low-pressure die casting lie in the pressure source, filling method, and flow state of the molten metal:
High-pressure die casting uses mechanical injection tools (injection pistons). At high pressure (tens to hundreds of MPa), the molten metal is forced into the closed mold cavity by high pressure. The molten metal fills the closed cavity wall in the form of high-speed turbulent flow, making it suitable for thin-walled and complex workpieces.
Low-pressure die casting uses low-pressure gas (usually 0.05-0.15 MPa) to press on the surface of the molten metal in the crucible. The molten metal is smoothly pressed into the mold cavity through a riser tube, filling the mold from bottom to top in a laminar flow state. The pressure is uniform and the filling is slow, which can reduce defects such as air holes.
