An Evaluation on Machinability Characteristics of Titanium and Nickel Based Superalloys Used in Aerospace Industry

Superalloys are a group of materials that are commonly used in aerospace applications and are also called high temperature materials, as they have superior wear and corrosion resistance. Ni-based superalloys are used more often than Ti alloys in the aerospace industry as they have mechanical and physical properties such as superior temperature resistance and toughness, high corrosion resistance, excellent fatigue and creep resistance. Ti alloys, on the other hand, have the highest strength / weight ratio among metals, increasing their preference in these industries continuously. Casting, forging, powder metallurgy and machining methods are used in the process of shaping machine parts used in the aviation industry from superalloys. However, many components are mostly manufactured using machining methods due to the part geometry, desired size and surface quality requirements. In this context, in the production of parts from Ti alloys and Ni-based superalloys, which are difficult to process, the correct selection or optimization of processing parameters is very important in terms of minimization of processing costs and therefore sustainable manufacturing. In this study, criteria such as cutting tool quality, tool life, surface integrity and cooling / lubrication technology, which have an important place in the machinability of titanium and nickel-based superalloys, have been compiled based on current literature studies.