Is chrome’s future less than bright? Will anodized aluminum, which some say delivers a finish that’s just as brilliant as chrome, take its place? Here’s the latest in automotive finishing.

Automotive finishing trends are driven by the economy and the environment. While economic pressures are forcing shops to find cost-effective finishing processes, environmental concerns are pushing potentially harmful coatings such as hexavalent chromium (hex chrome) out and leaving an open door for chrome alternatives such as anodized aluminum. Here’s the scoop on chrome’s future and anodized aluminum’s potential:

Chrome to Get the Boot

Hex chrome’s decades-long job as a corrosion inhibitor in the automotive industry is in jeopardy. Its days became numbered when the European Union issued a directive banning its use as a conversion coating on all cars in all EU nations, starting in July this year.

The directive specifies that after July 1, 2003, vehicles cannot be manufactured with over two grams of hex chrome. In response, global companies, such as General Motors and Ford, are phasing out the material.

“We’re moving toward producing more ‘green’ automobiles,” says Brad Majoy, manager of the specialty products division at Pavco Inc., which develops and provides technologies for the metal finishing industry. “One of the biggest examples of this is the move from hex chrome to trivalent chromium. And I think, eventually, the elimination of chrome altogether.”

In fact, most suppliers already have alternatives to chrome, though such solutions are admittedly not as economical as using chrome, which calls for only an inexpensive dip process.

Moreover, demand for such alternative technologies suffered when GM and Ford pushed back their hex chrome ban from July 1, 2002 to the 2005 model year, says Majoy. In addition, it’s still hard to beat hex chrome’s self-healing capabilities—it bleeds out to deter corrosion in minor scratches and cracks.

Down but Not Out

Chrome will continue to endure as a decorative finish. It will stick around in smaller car parts because the planned hex chrome phase out by GM and Ford does not extend to chrome-plated components like bumpers. “Chrome bumpers are a matter of style and nickel/chrome bumpers are actually starting to make a comeback,” says Majoy.

Shiny chrome-plated wheels are also far from finished—in the figurative sense. “The use of chrome plating on aluminum wheels is also growing,” says John Scharf, strategic industry marketing manager at MacDermid Inc., which provides services such as electroplating and surface preparation. “There has been some use of a paint designed to look like chrome, but there isn’t a strong demand for it; it is not capable of the same mirror-like brilliance of a chrome-plated wheel.”

Anodized Aluminum Beats the Blues

Although chrome-plated bumpers and exterior parts continue to be popular, anodized aluminum, which also delivers a shiny finish, may soon make some headway in exterior trim components. It has recently increased its appeal by controlling its tendency to turn blue when exposed to very high or low pH levels—which are present in acid rain and in alkali-rich solutions commonly used in touchless car washes.

Previously, extreme pH levels caused anodized aluminum exterior parts to form a blue, mold-like patina. But now, exterior trim manufacturer Decoma International Inc.’s Anotech subsidiary claims that it’s got the problem licked.

First, Anotech replaced a pre-sealant made out of nickel with one composed of lithium, which is less susceptible to substantially high or low pH levels. Second, the company encapsulated parts with a weatherable acrylic urethane made by PPG Industries.

“In the end, we needed an organic coating solution to combat the organic problem of extreme pH levels,” says Gary Chevalier, assistant general manager at Anotech. “The coating is incredibly resistant to alkali attacks. We hit it with a pH of 14 for two hours and it did great.” What’s more, the waterborne e-coating process that applies the coating has a transfer efficiency rate that approaches 100%.

Although it hasn’t made any formal announcements yet, Anotech says the encapsulation material will soon appear on some production vehicles. Now that getting the blues is no longer a concern, Chevalier believes that more automakers will use anodized aluminum.

Anodized aluminum beats chrome for exterior trim components such as garnishes and moldings, says Anotech general manager Dave Clark, for several reasons. First, unlike chrome and chrome-plated parts, anodized aluminum can easily take on most colors and can attain texture through laser etching or sand blasting. Second, it can be made to look just as shiny as chrome—and for less cost, claims Clark.

He says, “For a bright finish, there is a real cost advantage compared to chrome and chrome-plated parts, (and) the customer often can’t tell the difference.”

Sources: Driving Forward: A Look at Future Finishing Trends in the Auto Industry
Kristy Schlossberg
Finishers’ Management, Oct. 2002
http://www.finishers-management.com/oct2002/autofinish.htm

New Approaches to Trim Treatment
Kermit Whitfield
Automotive Design & Production, Dec. 2002
http://www.autofieldguide.com/

Hex Chrome Help: What are Your Alternatives?
Kristy Judycki
Finishers’ Management, April 2002
http://www.finishers-management.com/april2002/hexchrome.htm