Alternatives to Hard Chrome: The Next Generation of Wear-Resistant Coatings

Just because something has long been the go-to doesn’t mean it will stay the industry standard. From the transition of wrought iron to steel, many once indispensable materials have paved the way for their newer counterparts. For decades, hard chrome has been the default solution for manufacturers in the automotive, industrial, and aerospace industries. Today, the newest generation of wear-resistant coatings is shaking up the industry, boasting an exciting range of sustainable and effective applications.

Three Reasons to Explore a Hard Chrome Alternative

#1: Health Issues

One of the more serious consequences of relying on hard chrome is the inherent health risk. The hard chrome plating process involves hexavalent chromium, which is a known carcinogen. Along with cadmium, cyanide, and chlorinated solvents, hexavalent chrome has been reported to cause damage to major organs such as the heart, lungs, and kidneys. Because of the substantiated risks hard chrome poses to both human health and the environment, both the EU and the US have introduced stringent legislation aimed at banning or severely restricting the use of hard chrome. In the US, the Toxic Substances Control Act (TSCA) has led to stricter regulations of hard chrome, making this once popular coating significantly less accessible.

#2: Environmental Hazards

The traditional hard chrome plating process involves the production of toxic waste. Before the restrictions and protections put into place by the EPA and OSHA in the 1970s, it was commonplace for chrome baths to be dumped into city sewers and pollute the water supply. While regulations are stricter today, there are still significant costs associated with hard chrome compliance, including proper disposal and handling of these materials. More eco-friendly alternatives are focused on reducing harmful waste byproducts and their impact on our environment. 

#3: Performance Limitations

While hard chrome can offer substantial wear resistance and has often been lauded for its performance at high temperatures, it is no longer the benchmark as newer options have emerged. Many alternative coating solutions have demonstrated higher hardness, wear resistance, and protection against abrasive wear. Hard chrome plating (HCP) routinely shows reduced porosity and corrosion risk from the outset, as well as limited ductility and lower fracture toughness. Typically, HCP only displays a hardness range of 60–70 HRC. Furthermore, HCP can sometimes exhibit micro-cracks, which can allow corrosive agents to reach the substrate and wear down components over time.

Introducing the Next Generation of Wear-Resistant Coatings

Thankfully, HCP is not the only game in town. The future of coatings remains bright in part due to a sweeping array of alternative wear-resistant materials.

Physical Vapor Deposition (PVD)

This thin-film coating uses a specialized vacuum to vaporize solid materials and deposit them onto the substrate. A PVD adapts well for parts that are small enough to both fit inside the vacuum chamber and withstand scorching temperatures up to 800°F. Another benefit of PVD is that it can be applied in very thin ranges of 0.0001” to 0.0004” and can achieve the same surface finish as the substrate. As a result, PVD coatings are best suited for small, intricate parts that require thin, multi-faceted coatings.

Electroless Nickel Coatings 

Another alternative to hard chrome plating can be found in electroless nickel coatings. These coatings are employed in a similar style to hard chrome and can typically be applied from 0.1 to 5 mils thick. Electroless nickel is more ductile than hard chrome and has been shown to be heat resistant up to 1600°F. A benefit of this type of plating is that it can be hardened post application and utilized on most substrates. However, it is important to note it may require extra processing. Overall, this coating is ideal for any components that need a coating process similar to hard chrome. 

BTHC-0005™: A Modern Upgrade

Industries such as mining, steel mill production, and manufacturing demand coatings with superior mechanical properties. Our preferred thermal spray application, BTHC-0005™, offers wear protection, corrosion resistance, and impact resistance. In fact, real-world case studies show 3–16x longer lifespan for parts coated with BTHC-0005™ compared to chrome plating. 

We saw evidence of this durability firsthand with our client’s mold cavity that had been previously coated with hard chrome. When our client made the switch to BTHC-0005™, they were able to achieve over 18,000 presses and counting compared to the initial 3,000 presses with hard chrome. This versatile coating is able to combine high hardness (1400+ Vickers) with ductility, allowing for better impact and cavitation resistance. Furthermore, salt fog testing shows BTHC-0005™ lasting 1000+ hours without rust bloom, significantly outperforming both chrome and HVOF. BTHC-0005™ also lends itself to diverse applications since it can be applied to thicknesses ranging from 0.002" to over 0.050".

Lastly, BTHC-0005™ is an inherently sustainable coating choice as it demonstrates reduced wear rates with a volume loss of only 4.15 mm³ vs. 28.6 mm³ for hard chrome. This means components coated with BTHC-0005™ will need to be replaced or repaired less frequently. 

While change can often be destabilizing, the influx of more wear-resistant, sustainable, and durable coatings has paved the way for a more flexible future. Industries now have the option to match their precise component’s needs with a suitable coating. BTHC-0005™ continues to lead the way as a premier hard chrome alternative, offering unmatched durability, safety, and economic performance.

Curious to learn more? Contact HTS Coatings to learn how BTHC-0005™ can transform your equipment’s lifespan and bottom line.