You may have heard of crucibles, because crucibles are common in life. Graphite crucibles, silicon carbide graphite crucibles, clay crucibles, ceramic crucibles, and so on are often used. As the name implies, crucibles are used to melt and cast some metals, which involves the melting point of containers and fused objects. Today, let's take graphite crucibles as examples to share:

firstGraphite crucibleThe raw material of graphite is mainly graphite, so the high temperature resistance, high melting point, corrosion resistance, oxidation resistance and other characteristics of graphite are also reflected in the graphite crucible. Just now, I said that the melting point of the container and the object to be melted must be different, otherwise there will be no interaction. If the graphite crucible can only be burned to 1000 ℃, then the melting point of gold is 1064 ℃. It is obvious that the melting point of gold is higher than that of the crucible. This is not feasible, that is, the crucible has been melted before the gold reaches the melting point. What is the actual melting point of the graphite crucible? That is to say, how many degrees can a graphite crucible burn.

This has to start with the nature of graphite, because the ignition point of graphite under absolute oxygen is as high as 3000 ℃. What if it is in air? That's even higher. It can be as high as 3652 ℃ ~ 3697 ℃. That is to say, the graphite crucible can be burned to 3697 ℃ for sublimation, and the melting point of the graphite crucible can at least reach 3652 ℃. At this time, let's look back at the melted objects: Gold: melting point 1064 ℃, copper: melting point 1083 ℃, silver: melting point 962 ℃. When we see the melting points of copper, gold and silver, have we found that they are insignificant under the melting point of the graphite crucible? Therefore, graphite crucibles are also often used as silver melting graphite crucibles, gold melting graphite crucibles and gold melting graphite crucibles, which are often used in laboratories.

After a brief introduction, I believe you have a better understanding of the physical properties of the graphite crucible. Extended reading:Application of graphite crucible