One of the main problems that can affect the quality of the final product during the Zamak die-casting process is the presence of porosity, or small air bubbles trapped in the die-cast part.

It is impossible to completely avoid the formation of porosity, which is inherent in the die-casting process, but it is essential that, depending on the different applications of the moulded products, certain tolerances are respected. Otherwise, the quality and reliability of the parts can be compromised on several fronts:

  • Leakage in pressure tests
  • Lower tensile strength and load stress
  • Aesthetic defects in the case of electroplating

How to reduce the formation of porosit

The presence of porosity is due to the formation of air during the filling phase of the mould cavities. To reduce this problem, it is essential to adopt controlled and rigorous merger practices, using equipment and procedures to maintain a stable thermal balance of all moulding parts and a material flow rate that optimises filling.

It is therefore important to pay attention to the design of the mould and the correct configuration of the casting and injection systems. An optimized metal flow can help reduce the formation of porosity in the finished piece. The use of casting simulation software and the correct application of the principles of fluid dynamics in the design of the mould help us to ensure a uniform and optimal sliding of the molten metal, thus reducing the risk of porosity.

Other factors that may influence the formation of porosity include temperature and pressure during the die-casting process. Keeping these process parameters under control helps to ensure optimal mould filling and reduce the formation of air bubbles in the finished part.

Finally, strict quality control is essential to identify and correct any defects before the finished part is delivered to the customer. Through the workpiece section, leak testing or non-destructive inspection techniques, it is possible to identify and evaluate the presence of porosity, allowing timely corrective interventions in the mould or in the moulding parameters.

Airzero Project

Thanks to the many years of experience developed in the gas regulators sector, which is known to be very sensitive to the problem of porosity, Nuova Framar today pays particular attention to this issue. This attention translates into particular design principles, specific training methods for production workers and advanced process monitoring systems, as well as continuous research and development of company know-how to minimize this problem.

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