Effects of cutting parameters on machinability characteristics of Ni-based superalloys: a review

Abstract

Nickel based superalloys offer high strength, corrosion resistance, thermal stability and superb thermal fatigue properties. However, they have been one of the most difficult materials to machine due to these properties. Although we are witnessing improved machining strategies with the developing machining, tooling and inspection technologies, machining of nickel based superalloys is still a challenging task due to in-process strains and post process part quality demands. Selecting optimum machining parameters for quality, productivity and profitability is of paramount importance. Many studies have been conducted on various aspects of machinability of nickel based superalloys including defining the optimum cutting parameters, to develop a better understanding of machining them. The recent studies suggest new findings, and discuss previously reported results, related to the concerns of superalloy machining. This review presents the influences of the most significant cutting parameters on various machinability characteristics with respect to the recent studies as well as the previous ones. The reviewed machinability characteristics may be listed as: tool wear, cutting forces and surface integrity.

Machinability of Rene 65 Superalloy

“…High tool tip temperatures cause excessive tool wear, which reduce productivity. These temperatures can range from 1100 °C to 1300 °C and in turn, may cause severe wear and plastic deformation of the cutting tool edge [6].…”

“…However, in the case of superalloy machining, the process is significantly more costly than for steels. This is due to limitations in cutting speeds when machining superalloys [6]. Despite recent advances in near-net shape operations such as precision casting and forging, machining still plays a crucial role in the finishing and rectification processes [7].…”

Tailored Chip Breaker Development for Polycrystalline Diamond Inserts: FEM-Based Design and Validation

“…Given their high performance under severe working conditions, via mechanical and thermal stresses and harsh chemical environments [1,2], superalloys and advanced materials have been widely used in the manufacturing of components for jet engines [2], turbochargers [3] and aerospace [4] applications. Nevertheless, these materials display difficult machinability characteristics [5,6] due to their low thermal diffusivity [2], high strain hardening [7], high chemical reactivity [8], carbide precipitation in grain boundaries [1] and high ductility [9]. Chief among these machining attributes, the high ductility of machined workpieces ordinarily leads to the formation of long continuous chips during the machining process, which negatively affects the safety, efficiency and continuity of the machining operation [10].…”

The Effect of the Feed Direction on the Micro- and Macro Accuracy of 3D Ball-end Milling of Chromium-Molybdenum Alloy Steel

“…Several types of such materials can be distinguished, depending on their features. The most known types are materials with low thermal conductivity, such as super alloys and titanium, a ductile material such as pure nickel, a material with high hardness and brittleness, such as ceramics [1][2][3]. The characteristics of each type of material have a large impact on the choice of machining methods, conditions, equipment and tools.…”