You might have a good knowledge about the pores on our face or about the porous nature of substances such as wood. Yet do you know that the porous nature of wood leaves the material open for uninvited invaders such as bacteria and water? This will result in the faster deterioration of the material. The same happens when there is porosity in a metal.
Porosity is a big concern in the die casting of metal parts. If there is porosity in your finished metal product, then you can confirm that there is some sort of damage in the metal. However, the good part is that porosity does not always mean that the casting is damaged.
If you conduct a full inspection of the final product, then you might be able to find out whether it meets your structural integrity and stability requirements. The porosity in metals is actually found when there are small or minute holes, voids, or pockets of air in the metal.
Porosity in metals usually happens when the air is trapped in it by the machinery used for die casting. This might often leave gaps at the top portion of your die or it might make the process of filling a mold a lot slower. If the air that is used for forcing the metal into the mold escapes through the overflows or vents, then it might also cause porosity in die casting parts. Some of the other causes of porosity in die casting parts are:
- Irregularity in design of cast and mold parts
- The purity of the alloy or metal, which is being used in the die casting process.
- Shot speed and pressure of the die casting machines
- Shrinkage in the wall thickness of the material
- Presence of too much lubricant within the die
- Low temperature of the metal
- Sharp corners in the mold
One of the most simplest and common ways to check for porosity in die casting parts is through an X-Ray of the metals through computerized tomography. However, you could also cut and polish sections from the metal and then analyze it under a microscope.
If you monitor the die casting process carefully and efficiently, then you will be able to control porosity to a specific extent. You only need to make sure that your process monitoring is specifically concentrated on equipment stability and maintenance.