In the manufacture of metal components using die casting, the correct selection of the alloy is crucial to ensure that the final part meets the mechanical, functional, and economic requirements of the project. At Gestión de Compras, thanks to our extensive experience as manufacturers, we advise and produce optimized parts, adapting the choice of material to the conditions of use, tolerances, finishes, and life cycles required.
1. Technical criteria for selecting the alloy
The decision is not limited solely to the cost of the material; multiple factors are involved:
- Mechanical properties: tensile strength, hardness, elastic modulus, and impact absorption capacity.
- Corrosion resistance: key for applications in aggressive environments, such as automotive, marine, or chemical industry.
- Thermal and electrical conductivity: relevant in heat management components or parts with electrical functions.
- Behavior in the injection process: fluidity, shrinkage, and tendency to generate porosity.
- Surface finishes and post-treatments: anodizing, painting, chrome plating, or protective coatings.
2. Main alloys used in die casting
Aluminum
- Properties: Excellent strength-to-weight ratio, good corrosion resistance, and high thermal conductivity.
- Applications: Automotive (engine blocks, housings), electronics, lightweight structural parts.
- Advantages: Lightweight and high mechanical strength.
- Limitations: Lower ductility compared to magnesium or zinc.
Zinc
- Properties: High tensile strength, excellent fluidity for complex geometries, good wear resistance.
- Applications: Precision components, hardware, gears, decorative housings.
- Advantages: High dimensional accuracy and excellent surface finish.
- Limitations: Heavy compared to aluminum and lower thermal resistance.
Magnesium
- Properties: The lightest structural metal, excellent vibration damping capacity.
- Applications: Portable electronics, aeronautical components, high-end automotive parts.
- Advantages: Significant weight reduction, good mechanical performance.
- Limitations: Higher cost and lower corrosion resistance without protective treatments.
Special alloys (Cu, Al-Si, Zn-Al)
- Properties: Composition adjustment to improve mechanical strength, hardness, or performance in extreme environments.
- Applications: Shipbuilding, energy, heavy machinery.
3. Cost-performance ratio
At Gestión de Compras, we understand that the choice of alloy should not be based solely on the cost of the material, but on its functional and productive value. We evaluate each project considering:
- Efficiency in the injection process: an alloy with better fluidity can shorten cycles and reduce defects.
- Mold durability: certain materials generate less wear, extending their useful life and reducing production downtime.
- Minimization of secondary operations: more precise finishes from the foundry reduce subsequent machining, polishing, or coatings.
- Total cost per part: the cheapest option per kilo is not always the most profitable; an alloy with better properties can reduce overall costs and improve in-service performance.
This comprehensive approach allows us to offer solutions that balance price, quality, and functionality, optimizing both the manufacturing process and the component’s service life.
4. Case studies and technical support
Our technical team has developed international projects where the correct alloy selection allowed us to:
- Reduce the weight of an electronic housing by 20% without compromising its strength.
- Increase the service life of a component exposed to saline environments thanks to a change in alloy and surface treatment.
- Improve dimensional accuracy and reduce internal defects by adjusting the mold design and injection flow.
If you would like to learn more about how we choose the ideal alloy for each project, you can download our PDF of die casting case studies from our website.
