Those in the zinc die casting industry understand the advantages of zinc die castings over other processes and materials. However, much work is needed to educate potential buyers of zinc die castings. This article, written with them in mind, highlights five reasons to consider using zinc die castings as an alternative to other materials and processes:
1. Higher Strength:
- Yield strength: Zamak 3 (the most common zinc die casting alloy) has a higher yield strength than Al380 (Aluminum die casting alloy) and AZ91D (magnesium die casting alloy).
- Impact strength: Zinc die castings are known for their superior impact strength over competing materials and processes. For instance, Zamak 3 has an impact strength greater than 15X that of Al380. This is a major reason why zinc die castings are commonly used for various electronic housing applications, etc.
- Stronger than steel? OK, zinc die casting alloys are not as strong as steel; however, they can be stronger than a steel weldment. The weak point on a steel weldment is not the steel, it is the weldment. Zinc die casting's ability to cast round corners and consolidate parts help strengthen the component, giving an overall improved strength even over steel.
2. Castability: The zinc die casting process is known to be a net shape process. Zinc is more fluid than other casting materials and can therefore form more complicated shapes and tough-to-fill sections. In most cases, machining is simply not necessary. In some cases, parts can even be in-die degated, which means that the trimming operation is eliminated because the parts are degated within the die casting machine.
3. Longer Die Life: The rule of thumb for die life in zinc die casting is 1,000,000 shots before replacing the die. This is approximately 10X longer than what is commonly found in the aluminum die casting industry. Smaller, less complicated tools can last the entire life of the product.
4. Part Consolidation: Does your process involve welding or other secondary assembly operations? Due to the higher fluidity and the ability to form very complicated parts, many progressive component designers and manufactures have been able to save money by consolidating multiple components and operations into one net shape zinc die casting, thus eliminating machining, gaskets, bushings, welding, etc.
5. Price (“First Cost is not Last Cost”): It is easy for purchasing agents to get too focused on comparing only material costs, especially in commodity-based markets. The zinc industry has struggled over the last couple of years, due to high metal costs, and is now returning to normal. However, metal price is only one component of the overall pricing picture. When factoring all the other advantages of zinc die casting over other materials and processes (such as longer die life, faster cycle times, ability to cast net-shape parts, and consolidating parts) the material price becomes far less important.
These are five of the more common advantages to using zinc die casting, but there are many others not mentioned here. Contact Eastern Alloys for more information, or to access its newsletter, The Alloyer, which is designed to help educate designers and engineers regarding the advantages of zinc die casting.