What Finish Is Right For Your Die Cast Parts? Part 2 | Electroplating & Electroless Plating

What Finish Is Right For Your Die Cast Parts? Part 2 | Electroplating & Electroless Plating

A die casting surface finish can provide durability, protection, and an attractive appearance. Last month we detailed the most common decorative finishes used in the industry – this article will delve a bit more into two types of plating that can be applied to die castings; electro-plating or electroless plating. What is the difference between the two processes and which would work best for your application?

Electroplating
Electroplating is a process where thin layers of metal are bonded at the molecular level with another metal. An electrical current is passed by two electrode terminals through a carefully prepared electrolyte solution where a metal part has been placed for plating. The electricity changes the surface properties of the part and allows it to bond with the metals in the electrolyte solution.

What types of metals can be plated this way?
• Platinum
• Gold
• Silver
• Chromium
• Copper
• Tin
• Aluminum*
• Zinc
• Cadmium
• Nickel
• Lead

*Aluminum has a tendency to form an oxide that may prevent proper plating adhesion. It is best to apply a zinc undercoating to aluminum parts before any type of plating.

Why choose electroplating?
• Improve appearance
• Improve the abrasion and wear resistance
• Corrosion protection
• Increase lubricity
• Increase the thickness of a part

What parts are commonly electroplated? Here are a few examples:
• Tools and dies
• Aircraft components
• Machine components
• Mechanical assemblies
• Electronics and computer devices
• Enclosures, chassis, and heat sinks
• Medical diagnostic instruments
• And many more

Electroplating 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. The main downside to electroplating is that it is very difficult to properly and evenly plate parts with complex shapes. The electroplating process also requires very clean conditions, utilizes possibly hazardous equipment, requires filtration, and typically requires multiple applications to achieve the desired look and thickness. In some instances electroless plating is the better alternative.

Electroless Plating
Electroless plating is quickly becoming one of the most widely used forms of plating today because it is more cost-effective and easier to do than electroplating. Electroless plating is used primarily as a protective and/or used to enhance electrical conductivity. In some cases, it can also be used as a decorative coating.

Electroless plating is also known as autocatalytic plating or conversion coating. Simply put, it is a process for plating a part without using an electrical current. The process for electroless plating basically involves dipping a part into a bath of plating solution where a reducing agent (like hydrated sodium hypophosphite) reacts with the ions in the part to deposit another metal alloy onto it (typically nickel).

A wide variety of metals can be plated this way, including (but not limited to):
• Aluminum
• Titanium
• Mild steels
• Stainless steel
• Hardened steel
• Copper
• Brass
• Zinc

Why choose electroless plating?
• Prevents corrosion and wear
• Adds toughness
• Resistance to abrasion
• Uniform deposits with consistent thickness
• Can be used on parts with very complex shapes

Due to the fact that electroless plating tends to create a very hard and non porous finish, this technique is very popular in industries such as oil fields or marine applications where parts are very vulnerable to wear and corrosion.

What other industries commonly use electroless plating? Here are a few examples:
• Oil and gas – barrels, pipes, pipe fittings, valves
• Automotive – gears, brake pistons, shock absorbers, cylinders
• Food service – food processing machine parts, molds
• Plastics and textiles – dies, machine parts, molds, extruders
• Aerospace – rocket parts, pumps, valves, pistons
• Chemicals – mixing blades, filer units, pumps, heat exchangers
• And so many more

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. It is vital for a 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 as well as the proper post-casting operations to achieve the optimum surface finish for the desired final plating result. Planning ahead for the finish you need can help to potentially minimize surface finish problems as well as any potential porosity issues.

With over 75 years of die casting surface finishing expertise, our engineers will evaluate your requirements to recommend the best approach to achieve the desired finish for your part. Contact A&B Die Casting today!

2019 | Happy Labor Day!

2019 | Happy Labor Day!

Labor Day, observed the first Monday in September, is a celebration of the labor movement and the contributions workers have made to the strength, prosperity, and well-being of our country. This US federal holiday is dedicated to the social and economic achievements of American workers. Enjoy your day!

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!

2019 | Happy 4th of July!

2019 | Happy 4th of July!

Happy 4th of July!
Please celebrate safely America.

Bald Eagle Trivia
1.) Benjamin Franklin, John Adams, and Thomas Jefferson served on the committee that picked the bald eagle for the US national seal (Franklin wanted it to be a turkey).
2.) Bald eagles have very few natural enemies and are only found living in North America.
3.) Bald eagles are not, and never were bald. The term comes from a time when “bald” meant “white-headed”.
4.) Bald eagles get their white head and tail feathers around the age of five.
5.) A bald eagle’s maximum flying speed is 40 mph. It is over 100 mph while in a dive.
6.) They can lift roughly half their own body weight.
7.) The only other kind of eagle that is naturally found in North America is the golden eagle.
8.) Bald eagles mate for life, but if one dies, the survivor will accept a new mate.
9.) It is a felony to shoot an eagle in the United States.

-A&B Die Casting

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

2019 | Happy Father’s Day

2019 | Happy Father’s Day

This year Father’s Day falls on Sunday, June 16th

“The older I get, the smarter my father seems to get.”
-Mark Twain

Happy Father’s Day everyone. The nation’s first Father’s Day was celebrated on June 19, 1910, in the state of Washington. However, it was not until 1972 that the day honoring fathers became a nationwide holiday in the United States.

-A&B Die Casting

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.