The Process Characteristics Of Aluminum Alloy Gravity Casting

Aluminum alloy gravity casting

It refers to the process of injecting molten metal into the mold under the action of other external forces (excluding gravity). Gravity casting is divided into high-pressure casting and low-pressure casting. High pressure casting is what we usually call die casting, that is, pouring aluminum liquid into the pressure chamber, filling the mold cavity at high speed through its gravity, and solidifying the aluminum liquid under gravity to form an aluminum casting.

The characteristics of aluminum alloy die castings are:

• The surface finish of the product is good, generally reaching Ra6.3 or even Ra1.6.
• No heat treatment.
• The product has high air tightness, high casting strength and surface hardness, but low elongation.
• The mold cost is high and the service life is short.
• High production efficiency.
• Thin-walled die casting parts can be produced with small machining allowance.

Aluminum alloy gravity casting

It refers to the process of injecting molten aluminum into the mold under the action of the earth’s gravity. Gravity casting is divided into: sand casting, metal mold (steel mold) casting, lost foam casting, etc. Now the most widely used metal mold (steel mold) casting is made of heat-resistant alloy steel. The strength, size and appearance of the cast aluminum castings are higher than those of other casting processes.

The molten aluminum of gravity casting is generally poured into the gate manually. It relies on the self-weight of the molten metal to fill the cavity, exhaust, cool, and open the mold to obtain the sample. The process flow is generally: molten aluminum smelting, casting filling, exhausting , cooling, mold opening, production cleaning, heat treatment, aluminum cnc machining.The characteristics of aluminum alloy gravity castings are:

• The surface finish of the product is not high, and pits are easily generated after shot blasting.
• There are few pores in the aluminum casting, and heat treatment can be performed.
• The product has low density and slightly poor strength, but high elongation.
• The mold cost is low and the mold service life is long.
• The production efficiency is low, thereby increasing the production cost.
• The process is relatively simple, and it is not suitable for the production of thin-walled parts.