What is the difference between aluminum and zinc alloys when die casting?

What is the difference between aluminum and zinc alloys when die casting?

Die casting is one of the most cost-effective, accurate, and versatile manufacturing processes in the world today. The process involves injecting molten metal, under pressure, into a reusable die (mold) and once solidified it can be ejected and finished (if necessary) in a variety of ways. The dies are generally constructed of high quality steel and the alloy cast is most commonly aluminum, magnesium, or zinc.

The alloy utilized in your casting will affect the part’s final properties, function, overall price, and life of your die. Aluminum and zinc are the two most popular metals to die cast and each have their own physical and mechanical properties which affect their cast-ability. Magnesium is the third most popular alloy to die cast but A&B does not work with it. Factors such as strength, longevity, melting temperature, and functionality need to be looked at closely before choosing the proper alloy. When choosing an alloy for your die cast parts machining and finishing operations also need to be taken into account.

Aluminum Alloys

Aluminum alloys are the most common alloys used in die casting today. They can be found in most items that we use every single day since are strong, lightweight, and economical for high-volume casting. Aluminum is very rarely used in its pure form because it tends to crack and shrink; therefore it is typically mixed with other materials including copper, magnesium, and silicon to help increase the alloy’s fluidity, elasticity, corrosion resistance, tensile strength, and hardness to provide it with superior mechanical properties. Aluminum alloy die cast parts tend to maintain their strength at high temperatures, possess good thermal and electrical conductivity, and can be cast with intricate geometries and thin walls while maintaining their strength.

Zinc Alloys

Zinc alloys are perfect for smaller and more complex shapes since no other alloys can be cast with such tight tolerances and thin walls. Zinc’s superior strength and hardness is an ideal alternative for machined, pressed, stamped, and fabricated components. Zinc also has excellent thermal and electrical conductivity, requires less tooling or secondary operations, and can be cast at moderate temperatures which provide significant energy and processing savings over other metals and engineering alloys.

How do you determine which alloy to choose for your die cast project?
Die casting offers the ability to create a wide variety of parts produced with precision at high speed. To determine which alloy would be best for your specific project you need to look closely at each alloy’s unique mechanical and physical properties since these will dramatically impact the performance and longevity of your application.

Other factors to take into consideration:
• Raw material cost
• Size of the finished part
• Wall size capability
• Tensile strength and hardness
• Weight requirements for the finished part
• Strength-to-weight ratio
• Dimensional stability and accuracy
• Corrosion resistance
• Thermal conductivity
• Electrical conductivity
• Finish needs and options
• Machining characteristics
• Recyclability

The alloy you select plays a huge role in the overall cost and performance of your die cast components. Since each alloy used in die casting offers its own unique benefits for your final die cast parts there is quite a lot to factor into the design and engineering of a new component.

It is not always easy to select the right alloy for your project. Need a hand? With over 75 years of die casting expertise, our team of experienced engineers will evaluate your requirements to help you decide which would be the best alloy option for your application to achieve the desired result for your part. Our in-depth knowledge and experience allows us to control the entire pre- and post-operative processing, as well as provide turn key part solutions with a variety of options, to meet our customer’s individual needs. Contact A&B Die Casting to get started on your next project today!

Die Casting with Zinc – Versatility with Economy

Die Casting with Zinc – Versatility with Economy

Zinc is a casting alloy that offers high precision with lower tooling cost for small parts. Zinc’s superior strength and hardness is an ideal alternative for machined, pressed, stamped, and fabricated components. Zinc is optimal for complex net shaped parts with thin walls while offering excellent electrical performance and shielding properties. Its structural integrity and wear-resistance are optimal for creating multi-faceted, complex shapes with a versatile range of physical, mechanical, and finishing characteristics.

The advantages of zinc die casting include:
• Complex shapes with thin walls
• Superior mechanical and physical properties
• Excellent tensile strength and dimensional stability
• RFI/EMI shielding capabilities
• Long die life
• Superior as-cast cosmetic finish

Zinc alloys are optimal for casting parts requiring intricate detail and close dimensional tolerances at high production rates. Zinc alloys are castable to closer tolerances than any other metal or molded plastic. Zinc casting alloys are stronger than reinforced molded polymers and zinc’s hardness, self-lubricating properties, dimensional stability, and high modulus make is suitable for working mechanical parts (such as gears and pinions).

For parts requiring hardness, high durability and cosmetic finishes, zinc die casting provides an economical solution while offering:
• High strength and hardness
• Excellent electrical conductivity
• High thermal conductivity
• Low raw material cost
• High dimensional accuracy and stability
• Excellent thin wall capability
• Cold Form capabilities to ease joining
• High quality finishing characteristics
• Outstanding corrosion resistance
• Full recyclability

Zinc also has excellent thermal and electrical conductivity, as well as precise casting tolerances, which makes it an ideal material choice for heat sinks, electrical components and applications that require electromagnetic shielding.

Zinc can be cast at moderate temperatures which provide significant energy and processing savings over other metals and engineering alloys.

The ease of use in die casting combined with high precision and lower tooling make zinc a top choice for designers from nearly any industry. Contact A&B Die Casting today to get started on your next project!

Die Casting with Aluminum – Versatility Meets High Performance

Die Casting with Aluminum – Versatility Meets High Performance

Aluminum castings are lightweight, possess good physical properties, high dimensional stability, high electrical conductivity, and are able to withstand high operating temperatures. Since aluminum also resists corrosion and can be easily cast. The majority of all die castings produced all over the world are made from aluminum alloys.

Aluminum is a very versatile material and is used for many applications; giving mechanical designers significant advantages when creating lightweight parts that withstand high temperatures. Aluminum die casting is often used in the defense and medical industries as a light and durable alternative to other metals while retaining maximum stability. It is also an exceptional thermal conductor for heat dissipation while maintaining rigidity and resilience when used for EMI/RFI shielding in the telecom and electronics industries.

Why choose aluminum?
• Lightweight
• High dimensional stability
• Corrosion resistance
• Excellent mechanical properties
• Good machining characteristics
• Superior EMI and RFI shielding properties
• High thermal and electrical conductivity
• High strength-to-weight ratio
• A variety of decorative and protective finishes
• Great choice for high temperature coating processes
• Made from 100% recycled material and is fully recyclable

With strength comparable to zinc alloys, aluminum is frequently chosen when weight is at a premium. One of the most significant benefits of using aluminum is that it has a very low specific gravity which places it amongst the most lightweight structural materials available today.

What are some typical applications for aluminum?
• Since aluminum castings are resistant to corrosion they are often used in marine grade applications.
• Aluminum is great for dissipating heat and is used in a broad range of networking and infrastructure equipment in the telecom and computing industries.
• Aluminum castings provide EMI/RFI shielding, rigidity, and durability.
• Die cast aluminum is ideal for electronic connectors and housings because aluminum has excellent electrical performance and shielding properties, even in high-temperature environments.

The best part?
With our strong commitment to protecting the environment, A&B uses only 100% recycled materials. The ease of use in die casting combined with lighter weight and durability make aluminum a top choice for designers from nearly any industry.

Want more in-depth information?
Click here to download a PDF that goes into some very good detail about aluminum alloys from NADCA’s product specification and standards for die casting.

Ready to get started?
Contact A&B Die Casting about your next project today!
(877) 708-0009

K-Alloy is A-OK for A&B Customers

K-Alloy is A-OK for A&B Customers

A304 (K-Alloy) was developed by Delphi in 2003 as an innovative aluminum die casting alloy that resists corrosion, but until a few years ago was only available from a smelter on the east coast. A&B Die Casting is delighted to announce that our west coast supplier is now a licensed source of K-Alloy, making access to the alloy simpler and recycling of the alloy more efficient.

K-Alloy/A304 has been tested to withstand 3,000 hours of salt spray testing with no metal loss or surface damage. Other aluminum alloys would require additional processes and/or coatings to withstand this harsh environment.

The rugged durability of K-Alloy can eliminate expensive processes such as anodizing, chromating, powder coating and painting that are designed to slow corrosion. In addition to cosmetic improvements, K-Alloy applications provide increased functional durability for aluminum cast components in harsh environments.

Originally developed to withstand extreme salt corrosion and temperatures, vibration, and shock experienced in vehicle engine electronics, K-Alloy aluminum is currently being used or being tested on products as diverse as fishing reels, outdoor lighting, furniture, water fountains, mail boxes, radios and vehicle roof racks.

Not All Alloys Are Created Equal

Not All Alloys Are Created Equal

Alloy composition is just one part of the equation for quality parts.

All alloys have unique physical characteristics to match specific engineering applications. The alloy affects the structural strength of a casting, the skin versus the core of the casting, and the ability to control the process to make the best use of the material.

While it is important to examine the composition of different alloys, it is just as important to ensure the purity of that composition.

Contamination of an alloy can easily result from two common practices:
• Re-melting metal that has already been through the casting process, such as scrap or defective parts.
• Re-melting runners or overflows from the casting process.

Over time, the gradual erosion of tooling can introduce traces of elements such as iron into the casting. These trace elements can slowly creep above acceptable ranges of a specified alloy when they are added back into the melt. Although higher levels of Iron (Fe) can help the die casting process by reducing sticking of the part in the tooling, it can produce an alloy that is out of spec over time if not managed well.

To eliminate the risk of contamination, A&B Die Casting never re-melts runners or overflows from our castings.
• A&B Die Casting sends all runners and overflows to our outside suppliers for recycling and requalifying of the alloy.
• A&B sources all our metal from top-quality suppliers Custom Alloy Light Metals and CASS located in the United States.
• A&B tooling uses premium H-13 that exceeds NADCA 207-2003 Superior Specification or better to resist erosion.

A&B Die Casting ensures the material our customers’ order is the material we pour for our castings.