Anodized Aluminum vs. Chrome for Automobile

The discovery of the chrome electroplating process by Columbia University scientists, Colin Fink and Charles Eldridge in the 1920s, saw the rise in the use of chrome in the automotive industry. Known for its resistance to corrosion, decorative properties, hardness, and durability, applications of chrome escalated after the second industrial revolution.

The world’s automotive chromium market was valued at approximately $14.3 billion in the year 2015 due to an increase in decorative plating demands and sales of passenger vehicles. Business Wire analysts forecasted the growth of the chrome industry to be in the region of 6% during the period 2018 to 2022.

While the future of the chrome industry seemed bright at the time, there have been several developments that indicate otherwise. As a result, the hunt is on to find and develop viable alternatives to chrome, such as anodized aluminum.

Chrome: A Material with a Dark Side

In the automotive industry, the most common form of chrome used is hexavalent chromium (hex chrome) but in the 1920s, hex chrome was found to be carcinogenic in nature after multiple incidents of lung and nasal cancer amongst workers arose. It was not, however, until 1980 that the U.S. Department of Health and Human Services (HHS) officially documented the material as cancerous.

Hex chrome has been proven to result in severe health issues not limited to cancer, but also including irritation of the nose, throat, eye, and skin, and damage to the kidney and liver. It also poses a threat to the environment as it introduces genotoxicity to botanic and aquatic life through the contamination of water from poor disposal practices.

Due to its nature, the European Union added hex chrome to its list of hazardous substances in 2003 and restricted its use in the production of electrical and electronic equipment to be sold from mid-2006. The EU’s End of Life Vehicle Directive dictated that preventative corrosion coatings made from hex chrome should be limited to 2g per vehicle.

In 2006 Ford would phase out the use of hex chrome in its worldwide operations. In the U.S., the Occupational Safety and Health Administration (OSHA) delineated that the permissible exposure limit for workers in the chrome plating industry should be reduced from 52 μg/m3 to 5 μg/m3. There was a further reduction in this value by OSHA in 2009.

Legislation limiting the use or leading to the elimination of hex chrome usage altogether continues to be implemented. In Europe, the Registration, Evaluation, Authorization, and Restriction of Chemicals (REACH) no longer permits the use of hex chrome as of 2017.

Advantages of Anodized Aluminum

As the negative effects of hex chrome have become more widely known, alternatives have been identified to replace its use in the automotive industry. One such promising substitution is anodized aluminum, which forms when aluminum is treated through an electrochemical process to produce a durable finish. An aluminum became increasingly popular in the automotive industry, increasing by 40% between 1995 and 1998, the use of anodization has followed.

Benefits associated with the use of anodized aluminum include:

  • Reduced costs in finishing and vehicle maintenance,
  • Durability leading to an extended life span and less maintenance, as products made from anodized aluminum are less likely to flake or peel,
  • A wide range of appearance choices, as its finishes come in numerous colors and can vary from textured to smooth or matte to bright,
  • Lowered shipping costs due to its lighter weight,
  • Lowered impact on the environment.

Anodized aluminum is also not harmful to human health if produced in a well-ventilated area, and proper procedures are followed.

Despite the hazards associated with hex chrome, chrome has still not been fully eliminated from today’s automotive industry. However, more organizations are looking to alternatives such as anodized aluminum since there are fewer risks associated with its widespread use.