Zinc Die Casting versus Aluminum Die Casting
Topic: Zn v. Al
Oftentimes we find, for product engineers and designers, aluminum alloy is the default when choosing a substrate for a die casting. There are strategic advantages for all casting alloys, yet Zinc is often overlooked. We would like to point out the benefits of zinc alloys, with the common trade name of Zamak, versus aluminum.
Exceptional Tool Life
A Zinc die’s tooling life can be more than 10 times longer than that of an aluminum die. Design dependent, Aluminum tools can last approximately 100,000 shots versus 1,000,000 shots for a Zinc casting die representing great capital savings.
Superior Thermal Conductivity
Zinc is a better conductor of heat than Aluminum which makes it perfect for applications like heat sinks or electrical components.
Low Melting Point
Zinc melts at 787.2°F whereas Aluminum melts at 1,221°F which provides a lower energy cost in processing.
Faster Cycle Times
The lower melting temperature and fluidity of Zinc allows for faster cycle times. Hot Chamber die cast machines can cycle much more rapidly than their Cold Chamber aluminum counterparts, providing Zinc with an advantage over Aluminum in processing cost.
Net Shape Casting
The exceptional casting fluidity of Zamak alloys allows components to be cast to net shape. The tighter tolerancing capable in Zinc casting reduces the need for secondary operations like trimming or machining.
Superior for Decorative Finish
Zinc is a less porous material than Aluminum which reduces the opportunity for pits and blisters to develop in processing, providing a smoother “skin” for finishing. Zinc die casts can be easily polished, plated or painted for class A results at a significantly lower cost than Aluminum.
Thin Wall Capability
The fluidity attribute of Zamak allows for thin wall die castings reducing material required to meet a designer’s functional requirement. Thinner, stronger walls result in smaller and lighter products with lower costs.
Zinc alloys are some of the strongest and toughest materials for die casting. Tensile strength, Yield strength, Shear strength are superior to Aluminum alloys.