• We have developed an environmentally friendly hard-film coating technology that synthesizes hard metal oxycarbides using a reactive sputtering method, with metal, carbon dioxide, and methane as the raw materials.
• During the metal oxycarbide synthesis, a small amount of rare gas was mixed in to promote carbon dioxide ionization and produce a tungsten oxycarbide coating.
• The chrome oxycarbide is extremely corrosion- and abrasion-resistant, while the molybdenum and tungsten oxycarbide are hard and abrasion resistant. In paticuler, the tungsten oxycarbide is the hardest of these materials. We expect these materials to be used as hard coating materials.

In recent years, there has been strong social pressure for the development of environmentally friendly materials. From the perspective of efficient use of resources, there is also increasing demand for hard-film coating technology to produce materials that are durable, highly reliable, and can be used with confidence.

Attention has been focused on metal oxycarbides that can form tough coatings on the surface of such materials as stainless steel and aluminum alloy. Metal oxycarbide compounds consist of a metal plus oxygen and carbon. Oxycarbides that include molybdenum or tungsten are extremely hard and have great potential for use as hard-coating materials. However, conventional production methods use environmentally harmful metal hexacarbonyls, so an alternative environmentally friendly production method is needed.

In our research division, we have developed an environmentally friendly hard-film coating technology that synthesizes hard metal oxycarbides using a reactive sputtering method, with metal, carbon dioxide, and methane as the raw materials.