Calcium has a different melting point and structure from aluminum alloy. Calcium has a very low solid melting degree in aluminum and forms a CaAl4 compound with aluminum. Ca can improve the cutting performance of aluminum alloy and reduce the strength of the alloy.
It is the degree of difficulty in cutting metal materials. If the material is easy to cut, it is said to have good machinability. On the contrary, it is said that its machinability is poor. Usually you can use the cutting tool, the cutting heat wear and tool durability, workpiece surface quality and cutting control to measure its cutting performance, high calcium content will affect the surface quality of aluminum ingots. And high calcium content will cause orange peel (2mm) on the surface of aluminum ingots. Besides, high calcium content will affect the aluminum liquid content air volume.
A small amount of calcium is good for removing hydrogen from molten aluminum. The effect of calcium in aluminum alloy on the performance of aluminum alloy after heat treatment. Calcium will reduce the as-cast hardness of aluminum alloy. Adding calcium to aluminum alloy will change the existing form of alloying elements and form new compounds. It is insoluble in the aluminum matrix when heated. As the calcium content increases, the hardness will gradually decrease after heat treatment.
Hardness and strength: The material has moderate hardness and strength, and its machinability is better. The higher the hardness and strength, the worse the machinability.
A small amount of calcium in the aluminum alloy melt is beneficial to remove the hydrogen in the aluminum liquid and improve the performance of the aluminum alloy. However, excessive calcium becomes an impurity in the aluminum alloy melt. Calcium will form a CaAl4 compound with aluminum, which has an impact on the mechanics of the alloy. The performance and heat treatment performance have an adverse effect. Therefore, in the production process, it is necessary to remove excess calcium in the aluminum liquid.
The granular decalcifying agent reacts with calcium to form a calcium compound, which is separated from the molten aluminum and floats to the surface of the molten aluminum for easy skimming.