Consistency is one of the benefits of powder metallurgy. On each cycle, a consistent weight of powder is deposited into the die and compacted to the same density.
Process economics dictate a near-net form manufacturing process with minimal after-work when order volume reaches a few hundred. Many engineers and buyers prefer die casting, but there are compelling reasons to consider powder metal, especially as new applications, materials, and design possibilities emerge as technology and understanding of Powder Metallurgy (PM) progress.
When comparing powder metallurgy and casting, it is important to consider the following factors:
A turbulent liquid fills the cavity in die casting. This can trap air, resulting in non-fills (when your material does not fully fill the mold). Internal defects such as flow lines and porosity can occur when oxide skin falls into the liquid. After casting, one will need to check for integrity and identify faulty parts; Leak testing, X-rays, Other inspection.
Consistency is one of the benefits of powder metallurgy. On each cycle, a consistent weight of powder is deposited into the die and compacted to the same density. Internal defects are extremely unlikely if the powder metal producer meets good housekeeping procedures and prevents powder contamination. Control over microstructure is a second benefit. This is determined by the cooling rate in die casting, which varies based on factors such as surface area and volume. Powder metallurgy allows for much more control over porosity and consistency, as well as the formation of finer microstructures.
In comparison to other processes, die casting has good shape-making capabilities. Powder metallurgy, on the other hand, allows for almost the same design possibilities but with improved mechanical properties. Die casting is done with non-magnetic materials. There is no magnetic applicability unless they are set inside another part made of another metal. Powder metal, on the other hand, has a wide range of magnetic materials.
Die-cast pieces are often flimsy and easily broken, which is a problem. The fact that the primary materials used in die-cast parts, zinc, and aluminum, are relatively soft metals does not help matters. Powder metal pieces, which are frequently made of steel, can withstand further violence. In the electric motor design, using a higher-strength material helps achieve the same shape with less material, potentially saving space and weight.