Material spotlight: ZA-27

Zinc-aluminium alloys were first introduced for gravity casting but are now sought-after materials for high-pressure, cold-chamber die casting. With zinc as the base metal, ZA-27 consists of 27 percent aluminium and 2.2 percent copper. ZA alloys have higher concentrations of aluminium than traditional zinc alloys and unparalleled bearing properties—ZA-27 has the highest aluminium content of all three ZA alloys. Silver in colour, this zinc-aluminium combination is lightweight, dense and best suited for applications requiring optimum strength.

Benefits of ZA-27

ZA-27 provides a range of benefits and solutions for different die casting projects. In addition to its wear resistance and high-strength properties, ZA-27 offers the following specific benefits:

• High tensile and yield strength
• Corrosion resistance
• Non-sparking properties
• Hardness
• Good bearing and creep properties
• Lightweight
• Ease of machining
• Thermal conductivity
• Longer tool life
• Environmentally friendly and efficiently recyclable

ZA-27 applications

ZA-27 is an underappreciated metal for foundry use. It is three times stronger than typical cast aluminium and can have the tensile strength of grey cast iron. At Dynacast, we have successfully cast ZA-27. One of our customers in the safety restraint industry needed greater strength than standard aluminium alloys could offer. Our engineering team designed the part using ZA-27 and achieved the maximum required strength without failure.

ZA-27 can be used for a variety of projects but is best suited to bearing applications. It is easily machined, and castings can be readily polished, plated, painted or anodised. Due to its high melting point, ZA-27 is suitable for projects with service temperatures of ~150 degrees Celsius. ZA-27's non-sparking characteristics enable it to act as a natural bearing, providing cost savings as well as maintenance and reliability advantages over other cast metals—which is beneficial for the automotive industry. Other industries using ZA-27 include:

• Aeronautics
• Agricultural machinery
• Construction and building
• General engineering
• Textile machinery

Try our dynamic metal selector tool to compare the mechanical and physical properties of different alloys.

Die casting with ZA-27

The high-strength properties of ZA-27, combined with its castability, enable our engineering team to design for strength while reducing overall material content compared with competing materials. Using ZA-27, we can cast stronger parts with thinner walls. Customers whose parts failed when using A380 switched to ZA-27 and more than doubled their yield strength. Our engineering team has the experience and expertise to guide you through transitioning your project to ZA-27 or to assist with starting a new project from scratch.