What Finish Is Right For Your Die Cast Parts? Part 1 | Decorative

What Finish Is Right For Your Die Cast Parts? Part 1 | Decorative

A die casting surface finish can provide durability, protection, and a decorative appearance. Over the next few months we will explore different types of finishes and how they are beneficial for different types of die cast parts.

Due to the fact that a die cast part needs to be heated during decorative finishing processes (such as plating and painting), it is vital for the die cast part to have both a good internal structure and good surface finish. These are achieved through good design for both the tool and the component. Planning ahead for the finish you need can help to potentially minimize surface finish problems as well as any potential porosity issues.

Types of decorative finish:
• Smooth and Shiny: In cases where a smooth and shiny surface is required, the density of the casting itself must be higher so that the part can be plated and buffed repeatedly. This type of finish requires the most preparation of the casting to achieve a smooth surface under the coating. Smooth and glossy finishes have the least ability to hide any surface imperfections.
• Satin and Textured: For satin finishes, brushing or media blasting can be used to achieve the desired surface finish before coating.

The 5 Most Common Decorative Finishes:
1. Painting
2. Powder Coating
3. Antiquing
4. Ceramic Coating
5. Plating

1.) Painting

Painted

Lacquers, paints, and enamels can easily be applied to die cast parts and work for both decorative and protective purposes. As with any finish, special considerations must be taken at the design stages of the part to plan for the type of painting finish you need. Precautions are taken in order to remove any oils from the cast surfaces. For best results, a conversion coating is applied after cleaning to ensure good adhesion of the coating to the die cast surface.

2.) Powder Coating

PowderCoating

Powder coating is commonly used as a decorative finish because it is able to hide minor flaws in the surface, the thickness is better controlled and more uniform, it is quite durable, very glossy, and has great color consistency and vibrancy. Powder coating yields a very hard, high anti-corrosion finish which makes it better at resisting dings and scratches. Unlike paints, powder coating reaches its final cured hardness during the baking cycle. Paints continue to cure for a period of time after baking, which may cause a delay in subsequent assembly operations. Powder coating is also quite environmentally friendly because the process produces no hazardous air pollutants or waste byproducts.

3.) Antiquing

Antiqued

In order to create an antique look, zinc castings electroplated with copper (or any other of its alloying agents), can be covered in a layer of colored components, such as copper sulfide. This casting is then ‘relieved’ – a process which entails the removal of some of the colored layers on highpoints in order to present the underlying layer of the yellowish brass or the reddish copper. The parts are then treated with lacquer in order to prevent tarnishing.

4.) Ceramic Coating

Ceramic

Ceramic coatings provide a very thin and decorative coating for die castings. Similar in thickness to anodizing, ceramic coatings can be applied to the entire part surface and in some cases even internal threads can be coated. Since the coating is very thin, any surface imperfections in the die casting will show through. Care must be taken with surface prep operations to ensure the desired final finish is achieved.

5.) Plating

Plating

Plating can be applied to die castings using either the electroless or electro-plating processes. Electroless plating is used primarily as a protective and/or used to enhance electrical conductivity. In some cases, it can be used as a decorative coating. Electro-plating is capable of achieving the best cosmetic plating finish on die castings, since multiple layers of plating are applied and buffing/polishing can be performed after each layer. In general, plating processes are the poorest at hiding underlying surface conditions and require the most surface prep operations to achieve the desired final finish.

With over 75 years of die casting surface finishing expertise, our engineers will evaluate your requirements to recommend the best design and finishing options. Contact A&B Die Casting today!

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
www.abdiecasting.com

New Medical Device Shielding Requirements and Die Casting (IEC 60601-1-2: 2014 – 4th Edition)

New Medical Device Shielding Requirements and Die Casting (IEC 60601-1-2: 2014 – 4th Edition)

Update your products to the latest IEC standard in style!

When designing any product it is always best to make sure that safety is engineered in the initial design phase to eliminate delays and extra expenses later down the production path.

Most components manufactured for the medical industry now-a-days are made from plastics. Recently the International Electrotechnical Commission (IEC), who publishes the standards for medical devices, revised their standards for shielding electronic components within medical products. The new standard (IEC 60601-1-2: 2014 – 4th Edition) now requires two levels of protection to ensure that the device will contain any electrical shock hazards and shield patients and operators from harm if one level of protection were to fail.

Many medical devices house their electronic components in plastic enclosures that need to have a metallic paint or plating applied to meet shielding requirements. With the updated IEC standards, it is possible that the metalized plastic enclosure may not provide the required shielding to meet the enhanced standards.

In contrast the die cast industry has employed similar standards for years since metal is the material of choice for both the telecom and microwave industries. The process to plate plastic is quite expensive but with die casting there is no need to plate the final product to properly shield the electronics inside. Since die cast parts are inherently shielded, and this standard is just taking effect across the industry, it would be a good idea to re-evaluate your parts as it may now be cheaper to produce them out of die cast metal instead of plastic. A&B Die Casting has helped a number of its customers in the medical device, microwave, and telecom industries create enclosures that meet any shielding requirements in the industry.

What is electrical conductivity?

Simply, electrical conductivity is the measure of how a material accommodates the transport of an electric charge.

Metal Conductivity & Resistivity

Conduction in metals follows Ohm’s law which states that current is directly proportional to the electric field applied. The law, named after German physicist Georg Ohm, appeared in 1827 in a published paper laying out how current and voltage are measured via electrical circuits. The key variable in applying Ohm’s law is a metal’s resistivity. Electrical conductivity is commonly measured by siemens per meter (S⋅m−1) and represented by the Greek letter sigma (σ). One siemens is equal to the reciprocal of one ohm.

Resistivity is the opposite of electrical conductivity. Meaning that it measures how strongly a metal opposes the flow of electric current. This is commonly measured across the opposite faces of a one-meter cube of material and described as an ohm meter (Ω⋅m). Resistivity is often represented by the Greek letter rho (ρ).

Metal electrical conductivity and resistivity standards:

Note: The resistivity of semiconductors (or metalloids) is heavily dependent on the presence of impurities in the material.

So, what does this all mean?
Die casting is a cost effective solution for shielded enclosures that meets the latest standards put forth by the IEC.

Need assistance re-evaluating your medical device parts? Let us help! Since 1945 A&B Die Casting has been offering a quality diverse range of engineering, design, custom die cast, machining, finishing, and assembly services to our clients all over the world. Contact A&B Die Casting today.

A Few Tips to Reduce Die Casting Parts Costs

A Few Tips to Reduce Die Casting Parts Costs

Die casters employ a number of techniques to maximize tool and component design while reducing per-part costs.

What are the 3 main costs associated with die casting?

1.) Die Casting Production – depending on the part complexity, the die casting setup can be very labor intensive. The process also requires melting of the die casting alloy specified.
2.) Secondary Operations – any needed deburring, machining, sanding, or hand finishing to achieve the specified part finish.
3.) Finishing – any desired painting, plating, silk screening, or engraving.

When designing and engineering a new component you need to think beyond simple metal forming and think of die casting as the total manufacturing process. Shifting thinking along those lines can drastically reduce production costs as parts are then designed to eliminate waste as well as some secondary operations.

The largest part of the total cost to die cast something is the cost of the labor involved. The actual die casting process is one of the most efficient methods to go from raw material to finished/near finished part shape, while giving the designer the opportunity to include many features into the part that may be impractical or too expensive with other manufacturing methods.

Die casting can be incredibly cost effective because one part can be designed to replace multiple components. It is also possible to incorporate other features into the casting that eliminate secondary milling, boring, reaming, and grinding operations. One die-cast part can also eliminate assemblies that incorporate swaging, riveting, screw machining, stamping, press fitting, and welding.

What other factors affect die cast costs?
•Component complexity
•Alloy
•Part tolerances specified
•Part finishing specified

How can costs be reduced further?
Die casting does not have to be expensive. A thorough design for manufacturability (DFM) review is critical. Getting the die caster involved early in the process can greatly reduce part costs down the road. Depending on part complexity, this review may include a digital fluid flow analysis to help ensure the desired part shape is optimized for the die casting process.

On top of that, additional savings come from material reduction, improved tolerances, and good part-to-part consistency.

Much like any other engineering process or build, proper planning before production will drastically reduce your costs while speeding up the actual production time.

Need assistance or want to get started on your next die cast project?
Contact A&B Die Casting today!

Die Casting and Part Geometry

Die Casting and Part Geometry

What’s the most cost effective way to cast metal parts with minimal machining?
Die casting.

Die casting allows you to create sharply defined smooth – or textured – surface metal parts from a durable range of non-ferrous metals, such as zinc, magnesium, aluminum, and an array of composite materials at high-speed and with precision. The type of metal chosen to fabricate the part determines whether it will require the hot chamber or cold chamber method to inject the metal into the die. Die casting enables the production of components with fine details like lettering, textured surfaces, and other features without the need for additional processing.

The main benefits of the die casting process include:
•High quality: Die cast parts deliver a long service life.
•High reliability: Exceptional uniformity of mass-produced parts.
•Quick production: Die cast tooling requires minimal maintenance.
•Versatile: Die casting can create virtually any size, part geometry, surface texture, or luster.
•Minimal assembly: Assembly features such as studs, drill holes, and bosses can be integrated into the mold design.

What effects die casting the most?
Part geometry.

The initial part design is crucial and determines how parts fill and cool – part geometry affects the porosity, grain structure and internal stress states. Stress concentrators, such as those found at sharp corners, are also geometry dependent and can reduce a part’s working strength. Parts whose geometry has been optimized for die-casting–in terms of filling, cooling, and ejection–will have substantially different microstructures and internal stress states than comparable machined or spin-cast parts.

Geometry planning works as an important influential tool on casting designs. Proper geometry planning will ensure time is not lost re-casting and counterbalance problems like:
•Defects
•Poor fluid life
•Shrinkage
•Solidification
•Temperature maintenance and effects
•Hot cracking
•Strength issues (compressive strength, impact strength, and tensile strength)
•Slag formation tendency

Advantages of proper geometry designs:
•It avoids defects: Reduces the need for multiple post casting quality checks, and reduces the number of rejected castings.
•Increases energy efficiency and reduces environmental impacts: an effective geometry design influences how much energy consumption is needed for cooling and lighting temperatures used in the manufacturing.
•Improves overall quality and life of the casting: with reduced defects and reduced lead-time to produce a casting, the overall quality and operational life of the casting is increased.

Our job at A&B Die Casting is to guide our customers to the best, most efficient process for their needs. With design for manufacturability in mind, we work with our customers to create features and sub-assemblies that fit into a single part while keeping the number of parts to a minimum. Through our rapid prototyping services, complete visualization of your concept is available to implement revisions if necessary before full production runs. By incorporating innovative engineering and state-of-the-art technologies, we take pride in designing and manufacturing the highest quality tools and parts at the right price.

Contact A&B Die Casting to get started on your next project today!

Vacuum Assisted Die Casting

Vacuum Assisted Die Casting

Bringing innovative technology to traditional craftsmanship.

Adding value to the die casting process is paramount to A&B Die Casting. One significant technology that A&B has embraced is vacuum-assisted die casting.

The basic die casting process consists of injecting molten metal under high pressure into a steel mold called a die. With a vacuum-assisted system, a vacuum is drawn in both the shot sleeve and the mold cavity before the injection shot occurs. Almost all air is positively evacuated from the mold and the vacuum is maintained until the injection cycle is completed. Vacuum-assisted die casting decisively reduces gas porosity in the casting. This significant reduction in the volume of gas porosity and the pore sizes in castings has the result of markedly improving the density and tensile strength of the end product.

A good vacuum in the mold cavity enables the alloy to flow into blind recesses in complex shapes. It also allows the fronts of the molten metal to merge freely without forming shuts.

Vacuum-assisted die casting offers benefits beyond simply reducing porosity.
• Larger, thinner, and more complex castings are made possible.
• Product density and strength are increased.
• Rejections due to porosity are virtually eliminated.
• Excellent surface quality is ensured.
• Less casting pressure is required, resulting in extended tool life and mold life.

Vacuum alone will not make a casting system more efficient. Vacuum supplements the efficiency of a well-designed casting process and extends its capability. It depends on the expertly engineered die cavities, runners, vents, and overflows designed by A&B tooling engineers.