Color Matching All Aluminum Parts

Article From: Products Finishing, , from Products Finishing

Posted on: 3/1/2000

New process provides a scratch-resistant finish and color matching among all aluminum alloys...

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WORKBOXES

WORKBOXES for trucks receive the Never Scratch finish.

Exhaust tips

Exhaust tips emerge from the chrome flash tank.

NEW PLATING line

NEW PLATING line in Corunna, Ontario, Canada

This one particular rack of aluminum parts did not look quite right to Max Wiener, president of Auto Anodics Port Huron, MI, as it emerged from the micro-etch tank. Wanting to correct the problem and being naturally curious, Max took the parts to his laboratory to find out what happened. Although the tank chemistry was quickly adjusted, for 5 weeks he hypothesized and tested, trying to figure out how the parts got the finish they did. Once he found the “error,” he also realized he had discovered a finish that did not scratch, resisted fingerprints and was harder than traditional anodized finishes, among other properties.

He found that the finish, “Never Scratch,” can be used on both stainless steel and anodized aluminum and decided to capitalize on the “mistake.” Auto Anodics first presented parts with the finish to DaimlerChrysler after the car company asked Auto Anodics to find a way to anodize high-silicon 356 aluminum castings for suspension parts of the Plymouth Prowler. “When we first went to DaimlerChrysler,” stated Max, “we took a box of parts with the Never Scratch and just dumped them on the table. Previously, we would wrap each part individually. With this finish there is no need to worry about scratching.”

Engineers at Ford did gravelometer tests on the finish on aluminum, comparing it to a strictly anodized aluminum finish. With anodized aluminum, deterioration begins after approximately 5 lb. The Never Scratch finish survived up to 12 lb without any deterioration. “What we have found,” noted Max, “is that the surface becomes a lot harder. This finish outperforms regular anodizing in corrosion resistance, durability and gravelometer testing.”

The finish also solves another problem that often occurs when painting aluminum after etching and/or anodizing. Painted aluminum finishes must be baked at approximately 375F for 30 min or more, which can put stress on the aluminum, potentially making it brittle. With the newer finish, no baking is required; therefore the aluminum remains flexible.

Auto Anodics is also working with Accuride, one of the biggest manufacturers of truck wheels in the world, to test the finish. The London, Ontario, facility of Accuride manufactures light, medium and heavy commercial vehicle wheels that are subsequently finished with Never Scratch. These wheels have been mounted on semi-trucks that travel daily from Missouri to Toronto. The test will run from the end of January through July of 2000.

“We will get to look at the wheels weekly,” noted Max, “this will help us learn a lot about the finish. With nonanodized aluminum wheels, you have a galvanic reaction between the wheel and the brake drum, and the lug nuts seize up after a couple of months. There is a tremendous amount of corrosion. We predict that with the Never Scratch finish and the stronger surface it provides there will not be any galvanic reaction or corrosion. The aluminum will remain soft and flexible.”

In addition to its functional properties, the finish is also decorative. It resists fingerprints and staining. It can also achieve a uniform look for all grades of aluminum when they are used together. “You can take a piece of 5052 aluminum and match it with a piece of 6061T6 and get the same color and finish,” noted Max.

This makes it an excellent finish for automotive exterior applications, since it can be used to match color on the wheels, luggage racks, window trim, running boards and other aluminum pieces on the vehicle, no matter what type of aluminum they are forged, stamped or extruded from. “That’s the beauty of the system,” commented Max.

The Never Scratch system is just the most recent of Max’s endeavors with Auto Anodics. The company began in 1988 when Max purchased Auto Anodics (then Trim Trends) from Harvard Industries. During the next 2 years he modernized the anodizing line and installed the first fully automated micro-etching, electropolishing and chrome flash system in the United States.

Micro-etching provides a uniform satin finish on parts, regardless of the surface configuration. Previously inaccessible areas are no longer inaccessible. It also improves corrosion resistance and leaves surfaces clean, providing for 100% paint adhesion on stainless steel.

Auto Anodics also has the capacity to color stainless steel. The coloring is a chromium oxide layer that is actually an extension of the substrate so there is no possibility of delamination. A variety of colors is possible.

Chrome flash achieves color matching for 200 and 300 (austenitic) series stainless steels when adjacent positioning is a concern. It also greatly enhances corrosion resistance on 400 ferritic series stainless steels. Exhaust tips and automotive trim for DaimlerChrysler, Ford, GM, Mercedes Benz and other automotive manufacturers constitute the bulk of Auto Anodics’ chrome flash work.

The electropolishing process at Auto Anodics is a special process that polishes and deburrs metal surfaces, removing all fines and super fine burrs. It also reduces the surface micro roughness. The process deburrs and smoothes corners and faces over the entire wetted surface, extending into holes, cross bores and recessed cavities. It also removes recessed burrs resulting from drilling and grinding operations. It excludes the dangers of hydrogen embrittlement since only oxygen is produced during treatment. The process operates without any mechanical distortion so that even sensitive components can be processed, such as hydraulic and pneumatic controls. The amount of metal removed is controlled by immersion time. The removal rate is 1-3 microns/min, depending on the hardness and composition of the metal.

This combination of processes has helped Auto Anodics offer its customers the first single automatic process line consisting of anodizing, electropolishing, chrome flashing and micro-etching of bright trim stainless steel and aluminum. The 56,000-sq-ft facility is strategically located near the Canadian border, allowing the company to accommodate customers in both Canada and the United States. However, the facility in Port Huron recently neared its capacity, and Max looked for ways to expand the business.

Max looked to Canada for his next venture, opening AFT, Advanced Finishing Technologies, in Corunna, Canada. Some of the reasons he decided to open the business in Canada were the higher unemployment rate and less expensive land.

The building in Corunna was designed with expansion in mind. The facility can easily be expanded to add more finishing lines, loading docks and office space. The finishing line is an exact replica of the line at the Port Huron facility. “This gives us flexibility and gives the customers reassurance,” noted Max. “If work is backed up at one facility, we can take it to the other facility for finishing. Same flight bars. Same solutions. Everything is the same.”

The Port Huron facility operates Monday through Thursday with Friday reserved for maintenance. The Corunna facility operates Tuesday through Friday with Monday reserved for maintenance. However, each plant is expected to be self-sufficient, and they do compete against each other for business.

He sees growth in the use of aluminum and believes it will be used more than plastics in future automotive design because it is recyclable. Plastics are recyclable. However, a recycled plastic is not as strong as the original plastic, and, therefore cannot be used for the same application. Also, anodizing becomes part of the aluminum; the color is integral. There is no paint or plating to flake or chip off.

Close ties with Europe also influenced Max’s thinking about the growth of aluminum in automotive manufacturing. (He works with Mercedes Benz, is Austrian and his father owns an Audi dealership in Austria.) More European car designers are incorporating aluminum into newer car designs. Max points to his new 2000 Audi as an example. The gear-shift box cover is anodized aluminum, whereas last year’s model was chromium plated plastic.

Max Wiener will continue to look for challenges. He loves to learn. He is truly a hands-on company owner, quickly grasping a slightly misaligned flight bar as it settled onto a carrier during our tour of the facility, even though he was dressed in a three-piece suit. He instinctively knows what is going on, what should be happening and what, if anything, is not working properly. He surrounds himself with the same type of people. And when something does go “wrong,” he is there to learn what happened and make it right.

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