How to Control Porosity in Casting
It is a risk to failure when many holes or voids within a casting part, knowing about the formation of holes, or pores, and what can be done to minimize them are important to the designer and engineers. Porosity is a concern for pressure die casting process. We can’t stop porosity, but we can control it through design, process and finishing. Let’s take a look at what leads to porosity and how to control porosity in casting by design and rapid manufacturing process.
Pressure Die Casting: What Is Porosity?
Gas or Inclusions is the reason leads to porosity, it refers to many holes or voids in Die Cast metal. Depending on the material being cast, there can be a little different in aluminum, zinc or magnesium.
Gas Porosity
Ambient air & gas micro-porosity are two types leads to porosity. Ambient air can be trapped inside the Rapid Tooling and must be evacuated via vents in the mold. Good part design will avoid sharp corner and deep pocket where air can be trapped. Gas micro-porosity takes place in the deeper section of casting part. The metal at the surface (close the tool walls) solidifies quickly with fine texture finish, however, molten metal that far away from tool walls takes longer time to solidify, the metal slowly contracts and creates minute voids.
Inclusions
Impurities in the casting metal, oil and moisture inside the mold, contamination from the environment are reasons for inclusions. We can stop it by using clean material and corrected quality control processes.
How to Minimize Porosity by Adjusting Your Design
Thin walls– no need to add more material onto the areas without great strengthen.
Allow porosity in areas with lesser mechanical stress
Consistent wall thickness
Rounded corner, avoid sharp 90-degree angles corner
Gussets
Bosses
Many of these design tips are similar to those for injection molding process.
TEAM Rapid is A Professional Pressure Die Casting Manufacturer
Rapid Tooling process is commonly used in the field of injection molding, aluminum die casting and serves a low to medium volume production, we are a rapid tooling China company, we know how to build injection mold and pressure die casting mold in lower price without comprising the quality, contact our expert team ([email protected]) and request a free quote today!
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