The difference between the properties of aluminum alloy forg

Forging process properties of aluminum alloy - activity, tightness, gas tightness, suction, hot cracking. What do these characteristics represent? What is the difference between die casting and aluminum casting?

 

Forging characteristics of aluminum alloy

 

Mobility: the ability of the alloy liquid to fill the mold. The size of the activity determines whether the alloy can forge large castings. Eutectic alloy has the best activity in aluminum alloy.

 

Shrinkage: one of the important characteristics of forging aluminum alloy. From liquid casting to agglutination, to cold to room temperature, the alloy is divided into three stages, namely liquid shrinkage, agglutination shrinkage and solid shrinkage. The shrinkage of the alloy has a decisive influence on the casting quality. It affects the shrinkage cavity, stress, crack formation and dimension change of the casting. Generally, casting shrinkage is divided into bulk shrinkage and wire shrinkage. In real production, wire shrinkage is usually used to balance alloy shrinkage.

 

Suction: easy to absorb gas, is an important characteristic of forging aluminum alloy. Liquid aluminum and aluminum alloy components and charge, organic combustion products and casting, and other water produced by the reaction of hydrogen produced by the absorption of aluminum liquid.

 

Air tightness: refers to the cavity aluminum casting under the action of high pressure gas or liquid leakage level, air tightness in reality represents the inner structure of the casting compact and pure level. The air tightness of cast aluminum alloy is related to the alloy's nature. The smaller the alloy's agglutination category is, the smaller the yield deviation is, and the smaller the precipitation porosity is, the higher the air tightness of cast aluminum alloy will be. The uniformity of the air tightness of the cast aluminum alloy is also related to the forging process, such as the low casting temperature of the cast aluminum alloy, the arrangement of chiller to accelerate the cooling rate, and the condensation and crystallization under pressure, etc., which can improve the air tightness of the cast aluminum alloy. It is also possible to improve the air tightness of the casting by blocking the leakage by leaching.

 

Thermal cracking: Thermal cracks in aluminum castings occur mainly because the shrinkage stress of the castings overtakes the cooperation between the metal grains. Most of the cracks occur along the grain boundary. It can be seen from the crack fracture that the metal at the crack is often oxidized and loses its luster. The crack extends along the grain boundary and is serrated in shape. It is broad in appearance and narrow in the interior. Some cracks ChuangTou the whole end face of the casting.

 

Difference between aluminum alloy forging and aluminum die casting

 

Forged aluminum alloy includes A1--Si--Mg--Cu alloy and A1-Cu-Ni-FE alloy. Commonly used forged aluminum alloy includes LD2, LD5, LDl0, etc. They contain more kinds of alloying elements, but less. Because of their excellent thermoplastic properties, forging properties and mechanical properties are very good. This type of alloy is mainly used for die forgings bearing loads and some forgings with complex shapes.

 

There are four types of cast aluminum alloy: A1-SI, A1-Cu, al-Mg and Al-Zn. For cast aluminum alloy, in addition to the necessary mechanical properties and corrosion resistance, it should also have good casting properties. Among the cast aluminum alloys, the best combination of casting properties and mechanical properties is A1-SI alloy, also known as si-Al Ming.

 

Full alloy forging shows good casting performance, low density, excellent corrosion resistance, heat resistance and weldability of cast aluminum alloy. For more information about aluminum forging, please contact us.