Sustainable ETA Carbide is a groundbreaking innovation developed by Sandvik Coromant that redefines the design of cemented carbides for cutting tools and wear-resistant applications. The project addresses one of the most pressing challenges facing the tooling industry: reducing dependence on critical raw materials such as tungsten additives, tantalum, niobium, ruthenium, and cobalt, while maintaining or improving the exceptional performance required in demanding machining operations. At the same time, the innovation significantly lowers the environmental footprint of cemented carbide production and supports the transition toward more sustainable manufacturing.

Traditionally, cemented carbides are based on tungsten carbide (WC) combined with a metallic binder, typically cobalt. To improve high-temperature performance and wear resistance, additional critical raw materials such as titanium, tantalum, niobium, and ruthenium are often introduced. However, many of these materials are associated with supply-chain risks, price volatility, geopolitical dependence, and high carbon emissions. The Sustainable ETA Carbide project explored an alternative approach based on the controlled use of Eta-phase carbides, a microstructural constituent that has historically been considered undesirable because it was associated with brittleness and reduced toughness.

The key innovation lies in discovering that Eta-phase can be deliberately engineered and finely dispersed within the microstructure rather than appearing as uncontrolled brittle regions. Through careful adjustment of chemistry, carbon content, sintering conditions, and microstructural design, Eta-phase particles can be tailored to mimic the role traditionally played by gamma-phase carbides containing tantalum and niobium. This enables the development of high-performance cemented carbides while dramatically reducing or eliminating the need for several critical raw materials.

The resulting materials demonstrate exceptional mechanical and tribological properties. The controlled Eta-phase reinforcement improves high-temperature strength, hot hardness, fracture resistance, and wear performance, making the materials particularly suitable for machining difficult-to-cut materials such as titanium alloys, heat-resistant superalloys, martensitic steels, and cobalt- or nickel-based alloys. Industrial machining tests confirmed that the new grades deliver equal or superior performance compared with conventional carbide grades. Depending on the application, tool life improvements of 30–60% were achieved while simultaneously reducing reliance on scarce alloying elements.

One of the major advantages of the innovation is its simplicity of implementation. The materials can be manufactured using conventional powder metallurgy processes already used throughout the cemented carbide industry, including powder mixing, spray drying, pressing, and liquid-phase sintering. No major changes in production infrastructure are required, enabling rapid industrial adoption. Importantly, the compositions are based largely on standard WC-Co systems with slight carbon adjustments, making them fully compatible with 100% recycled WC-Co scrap, thereby significantly increasing circularity.

The sustainability benefits are particularly compelling. Product Carbon Footprint (PCF) analyses show that Eta-carbide grades generate approximately 12.6 kg CO₂-eq/kg of material, compared with 15.7 kg CO₂-eq/kg for conventional gamma-phase carbides and 42.1 kg CO₂-eq/kg for ruthenium-containing grades. By eliminating or reducing materials such as tantalum, niobium, and ruthenium, the innovation lowers both environmental impact and dependence on highly critical supply chains. Combined with the possibility of using recycled raw materials, the technology offers a significant step forward in sustainable cutting-tool manufacturing.

From a financial perspective, the innovation reduces exposure to the extreme price volatility of critical raw materials. This is particularly important for ruthenium, whose market value has increased dramatically in recent years. By replacing expensive alloying elements with carefully engineered Eta-phase microstructures, manufacturers can lower raw material costs while maintaining or improving performance and productivity for end users.

The technology has already been transferred to production and is scheduled for commercial introduction by Sandvik Coromant in late 2026, targeting aerospace and automotive applications. Supported by multiple patents, Sustainable ETA Carbide demonstrates how a century-old material system can be reimagined through Powder Metallurgy innovation. By transforming what was historically considered a defect into a performance-enhancing feature, the technology delivers a unique combination of higher performance, lower environmental impact, improved circularity, reduced raw-material dependency, and enhanced economic competitiveness.