The melting point of aluminum alloys generally consumes a lot of heat and is easily oxidized, volatilized, and absorbed by some inferior metals.
1. A lot of calories are consumed: the melting point of aluminum is generally very low, but the potential for melting is very large, the heat is also large, the hardness is small, but the reflection of heat is very strong. Compared with some other metals, the amount of heat consumed during the melting period is very much.
2, it is easy to oxidize in the air: aluminum has a very high affinity for oxygen, in the air, it will soon be oxidized and produce alumina (AI203). A film of alumina can be formed on the outermost surface of the melt. Although this film has some protective effects, once it is destroyed, it enters the melt and is difficult to discharge. Because the physical properties of alumina are difficult to reduce, the other is that its density is very similar to the density of the melt. When it floats in the melt, it will enter the ingot together with the melt. That will bring some unnecessary trouble to the processing.
3, it is easy to inhale: the nature of aluminum and aluminum alloy is a strong inspiratory capacity (usually the ability to absorb oxygen), especially in the environment with a layer of water vapor or some other reducing atmosphere, suck The skill of oxygen is very strong.