Turning Operations of Aerospace Alloys

The turning operation is one of the oldest conventional processes utilized for manufacturing parts in the aerospace industry. This process configuration is ideal for producing symmetrical parts used in various rotating machines and engines within the aerospace sector. Materials commonly employed in aerospace applications typically possess high strength-to-weight ratios. Certain mechanical properties, such as fatigue life, are dependent on the surface quality achieved during the manufacturing process. Surface roughness and microstructure are influenced by the heat generated due to cutting forces and the cooling rate of the coolant/lubrication system. Selecting process parameters is a crucial and multiobjective optimization decision, where factors such as tool cost, machining time, and surface quality determine the target outcome. Numerous research studies have been conducted on the turning operation, each contributing to a better understanding of its mechanics. Among the different materials used in aerospace, aluminum and titanium alloys are the most common and appropriate due to their high strength-to-weight ratios. This chapter aims to provide a comprehensive overview of process parameter selection for these alloys and the main challenges associated with variable selection. A discussion on the formation of built-up layer (BUL) and built-up edge (BUE) in soft materials is included. In addition, the importance of utilizing proper cooling systems, such as minimum quantity lubrication and high-pressure cooling systems, is emphasized.