Nickel and its alloys are often used in industry when high corrosion and/or heat resistance is required. These special properties make nickel alloys ideal for use in extreme conditions, such as those found in power generation or aviation. A prominent example of this is nickel-based superalloys, which are used in gas or aircraft turbines, among other things, due to their outstanding strength and resistance to high temperatures. These materials are able to withstand the high thermal loads and corrosive environments in these applications, making them indispensable.
A characteristic feature of many nickel-based superalloys is the so-called γ' phase. This cuboid structure is located in a γ matrix and is crucial for the alloy's outstanding mechanical properties, especially at high temperatures. Metallographic etching processes are used to make these microstructural properties visible and to be able to evaluate them. Through targeted etching, the γ' structures can be displayed under the microscope, which enables a detailed analysis of the microstructure. The image on the left shows how this cuboid γ' phase is embedded in the γ matrix and how a clear picture of the structure can be obtained using suitable preparation techniques.
As with other alloys, nickel-based materials can also have a wide variety of microstructures. These structures depend heavily on the respective composition of the alloy and the heat treatment processes used. Light microscopic examinations make it possible to interpret these different types of microstructure and evaluate their effects on the material properties. This allows conclusions to be drawn about the corrosion and heat resistance as well as the mechanical resilience of the material, which is essential for quality assurance and the optimization of the alloy in various areas of application.
