Die casting (pressure casting) and gravity casting are the two most commonly compared processes in the selection of non-ferrous metal parts such as aluminum alloys and zinc alloys. Many procurement and R&D personnel only know that "die-casting efficiency is higher and the finished product is more exquisite", but lack quantitative understanding of the core difference between the two - "high pressure and high speed": producing an aluminum alloy shell in a single cycle by gravity casting takes several minutes, while die-casting only takes a few tens of seconds; The same thin-walled structure is prone to cold insulation and material shortage in gravity casting, but can be formed in one go in die casting.
The core difference between gravity casting and pressure casting can be seen from their names - the driving force for filling is completely different, which is also the root of all performance differences.
Gravity casting (represented by metal mold gravity casting): Pour molten metal into the sprue, rely on the metal's own gravity to naturally flow into the mold cavity, slowly fill, naturally cool and solidify, with almost no additional external pressure throughout the process. Partial low-pressure casting will increase low-pressure assistance within 0.1MPa, but it still belongs to the category of gravity forming in essence.
Pressure casting (die casting): By applying mechanical pressure through injection punches, molten metal is pushed into the steel mold cavity at extremely high speeds, maintaining a high pressure of tens to hundreds of megapascals throughout the entire process until the casting is completely cooled and solidified. The core feature is high-pressure forced filling+high-speed filling+continuous pressure holding solidification.
Simply put, gravity casting is the process of "metal slowly flowing in on its own", while die casting is the process of "using high pressure to drive metal at high speed". The significant difference in driving forces directly leads to a full dimensional differentiation in efficiency, accuracy, and molding ability.