Why should turbulent flow of molten metal be avoided during casting?

Turbulent flow of molten metal during casting can lead to significant issues in the final product. One of the main concerns is the acceleration of oxide formation. When the molten metal flows turbulently, it can incorporate more air and other contaminants into the metal. This increased agitation can cause oxidation, as the metal is exposed to more atmospheric oxygen. The presence of oxides can weaken the structural integrity of the casting by creating defects, leading to reduced mechanical properties.

Additionally, the turbulent flow can contribute to mold erosion, where the high energy and movement of the molten metal can wear down the mold material, resulting in further defects in the final cast. These issues can ultimately compromise the performance and durability of the cast product, which is why controlling the flow to maintain a laminar state, where possible, is considered beneficial in the casting process.