Magnesium is quite a popular metal and there are a number of reasons for this. In manufacturing, magnesium die casting is done different ways, but the goal is to produce precious castings that are going to deliver on the strengths of this unique metal. What we want to do today is take a look at the magnesium die casting process so you can better understand what is involved. In order to do that, we need to discuss the challenges of working with magnesium, how the process itself tends to work when using the die casting process, why manufacturers choose this metal and whether or not it just might be the next aluminum.
The Challenges of Working with Magnesium in Die Casting
One of the things that makes magnesium a challenge to work with is that those doing hot chamber die casting find its melting point to be too high. This is similar to the issue that aluminum poses, although aluminum does have a significantly higher melting point than magnesium does. If not done correctly, hot chamber die casting of magnesium can end up causing the magnesium to take some of the iron from the crucible during the manufacturing process and this is not at all desirable. More advanced hot chamber die casting processes have been invented to handle magnesium, but alloys containing it are often die cast using the cold chamber approach instead in order to avoid these issues. It should also be noted that, compared to alloys containing zinc, magnesium alloys tend to have a higher viscosity and this means that more pressure needs to be applied to the die in order to get the right kind of surface detail in the casting. Due to its high melting point, it also takes more energy to work with magnesium because it might be heated to such high temperatures. As we will see, however, for all of the challenges that die casting magnesium can present, there are plenty of other advantages that make it an excellent choice. It comes down to how the process is handled and the needs of the job in question.
Magnesium Die Casting Process Involves
The basics of the magnesium die casting process are the same as hot chamber or cold chamber die casting of other metal alloys. In hot chamber die casting, the plunger is pushed directly down into the melting pot and this must be done carefully. The metal will then shoot out the gooseneck and into the die where it is compressed, under massive amounts of pressure, until it is cooled. The die is then opened and if there are any cores, those are then retracted. In the cold chamber die casting machines, the molten metal is not touched by other components so there is less instance of thermal damage. The molten metal is loaded into a cold injection cylinder and then shot into the die where the casting process finishes in a similar way to the hot chamber method. It should be noted that the magnesium die casting process is a great deal faster if the hot chamber approach is used and this is why it has been perfected recently so that magnesium alloys will be easier for manufacturers to work with.
