Chip Formation Mechanism of Inconel 718: A Review of Models and Approaches

Abstract

Inconel 718, a nickel, chrome and iron alloy, has special advantages, such as high-temperature strength, thermal resistance and corrosion resistance, which facilitate wide usage in the aerospace industry, especially in the hot sections of gas turbine engines. However, machining this alloy is correlated closely with the material’s inherent properties such as excellent combination of strength, hardness and toughness, low thermal conductivity and the tendency to adhere to cutting tools. This nickel alloy also contains inclusions of hard abrasive carbide particles that lead to work-hardening of the workpiece material and thus abrasive wear of the cutting tool. That is, the machining of Inconel 718 is always influenced by high mechanical and thermal loads. This article reviews the chip formation mechanism of Inconel 718. One of the main characteristics in machining of Inconel 718 is that it will produce serrated or segmented chips in a wide range of cutting speeds and feeds. Existing studies show that the chip serration or segmentation by shear localization affects the machined surface integrity, and also contributes to the chip’s evacuation and the automation of machining operations. Thus, research conclusion indicates that the serrated or segmented chip phenomenon is desirable in reducing the level of cutting force, and detailed analysis of models and approaches to understand the chip formation mechanism of Inconel 718 is vital for machining this alloy effectively and efficiently. Therefore, this article presents some summaries on the models and approaches on the chip formation in machining of Inconel 718.

Research on the Cutting Force and Serrated Chips in Ultra-Precision Micro-Grooving of SLM Ti6Al4V Alloy

“…In addition, periodic adiabatic shear bands and micro-cracks were observed in the serrated chips. The serrated chips were micro-cracks on the chip-free surface caused by material extrusion [ 31 ], which induced the formation of shear bands. During micro-grooving, the reduction in the load carrying capacity of the material caused the shear band workpiece to move upward and forward in the nodules, eventually forming a complete serrated chip.…”

Sulfur Migration Behavior in Sintering and Pelletizing Processes: A Review

“…In addition, the raw material procurement, supply, and production process of general sintering plants are relatively stable. Liu et al [ 43 ] systematically calculated and analyzed the sulfur balance in the sintering process based on the production data of the Jingtang Sintering Plant. Subsequently, a relationship between the sulfur content of the sintering raw materials and SO 2 emissions was derived, with a control standard for low sulfur sintering raw materials.…”

“…The research showed that it was difficult to achieve SO 2 emissions directly by reducing the sulfur content of the raw materials. [43] However, other methods can be used to reduce sulfur input such as the introduction of clean technologies, including high proportion hydrogen-rich fuel sintering, [44] layered heating hydrogen-rich sintering, [45] and hydrogen gas injection. [46] These clean technologies show that not only SO 2 emissions can be reduced, but CO 2 emissions can also be effectively reduced.…”

Dynamics of chip formation during the cutting process using imaging techniques: A review

“…Priyadarshini et al 66 presented a brief overview of the application of FEM to metal cutting simulation. Recently, a detailed review 67 suggested that the causes and effects of chip segmentation need to be considered in the simulation to improve tool life prediction and select the optimal cutting parameters for improved product quality. Guo et al 68 investigated the chip formation mechanism using FEM considering a damage model.…”