The improvement of hard metals, especially their impact resistance and wear resistance, mainly depends on the characteristics of their microstructure and constituent elements. When producing these high-performance alloys, ruthenium, as a rare platinum group metal, becomes one of the important components of hard metals due to its physical and chemical properties.
Firstly, ruthenium can effectively improve the wear resistance of hard metals. In high-stress and high-impact application environments, traditional hard metals often quickly damage due to material fatigue. The addition of ruthenium can significantly enhance the overall hardness of the alloy because ruthenium can form solid solution phases in the binder, such as Co(Ru,W,C), which has higher microhardness and elastic modulus.
Secondly, ruthenium plays a crucial role in improving the impact resistance of the alloy. Impact resistance refers to the ability of a material to absorb energy without breaking when subjected to impact loads. Studies have shown that adding elements such as ruthenium can reduce the stacking fault energy of the cobalt phase and promote the polycrystalline transformation of cobalt from the cubic crystal form to the hexagonal crystal form. This structural transformation is conducive to enhancing the dispersion strengthening effect of the binder phase, thereby improving the material’s impact resistance at the microscopic level.
Furthermore, ruthenium’s role in enhancing the high-temperature performance of hard metals cannot be ignored. In high-temperature environments, the mechanical properties of traditional hard metals often decline significantly. However, when ruthenium interacts with other platinum group elements, it can significantly improve the alloy’s high-temperature stability. Studies have shown that ruthenium-containing single-crystal superalloys can maintain a stable microstructure after long-term aging, which helps the alloy retain excellent mechanical properties at high temperatures.