Hard material coatings of tools

To maximize the productivity and economic efficiency of components and tools, their service lives have to be extended, which means that the tools have to be used as long as possible without major damage due to wear. To reduce wear, components subject to high loads or milling and drilling tools for machining as well as molding tools are often provided with a protective coating. Such coatings should be extremely hard, viscous, and resistant to chemicals.

State of the art

Oxide ceramic coatings, such as coatings made of aluminum oxide, have a high hardness, temperature resistance, and are insensitive to chemicals. Metal hard materials, such as titanium carbide, are hard, viscous, and adhere well to metal carrier materials. Combination of the advantages of oxide ceramics and metal hard materials would be ideal.

Technology

KIT scientists of the Institute for Applied Materials - Applied Materials Physics (IAM-AWP) have developed a process to produce such hybrid materials. For this purpose, the researchers use a PVD (Physical Vapor Deposition) process. This process allows for extremely high quenching rates, such that substances are formed, which are insoluble in each other under conventional conditions, i.e. in thermodynamic equilibrium. As a result, single-phase mixed crystals of 1 to 10 nm in size are produced. They combine the positive properties of oxide ceramics and metal hard materials.

Advantages

In this way, scientists can produce coatings with properties tailored to the respective application.

Options for companies

In practice, the process has already turned out to be suitable for the coating of special tools and components. The KIT looks for partners interested in applying these innovative hard material layers.