Tool Wear and Surface Roughness in Machining of Metallic Materials

Dear Colleagues,

Tool wear is a major, well-known issue in metal cutting since process parameters are selected to provide the optimal productivity or economy. Tool life is normally accessed in terms of minutes. Physical, chemical, and thermomechanical mechanisms interplay to cause cutting-tool wear. Identification of the main mechanism is not straightforward and most interpretations are debatable, because many different simple processes of wear act simultaneously, with the dominating effect of one or more of them depending on the circumstances. Many factors are responsible for tool wear such as: (1) the cyclic nature of the chip production process can cause breaking due to thermal fatigue, and (2) the high contact temperatures and pressure at the tool–chip and tool–workpiece interfaces soften the tool material and encourage diffusion and chemical or (oxidation) wear. Fretting wear is another type of tool wear. Fretting is an oscillating movement between two solid surfaces in contact, often tangential, with a tiny amplitude. Fretting wear occurs when cyclic forces from loading and unloading produce surface or subsurface breakage and a loss of material, resulting in exposed frets. Hence, various tool-wear mechanisms in various machining activities under various cutting conditions must be thoroughly studied.

The way an object interacts with its surroundings is largely determined by its surface roughness, which is a part of its surface texture. To gauge a mechanical part's prospective performance, roughness is a useful metric to examine. Manufacturers and engineers cannot guarantee consistent and dependable production methods for each product without first ensuring surface control is maintained. In the context of precise surface engineering, surface measuring can be an important part of quality control by checking production against predetermined standards. So, in machining, the surface roughness of a machined part plays a vital role and depends on various factors that can be roughly organised into four distinct types: (1) variables resulting from alterations to machining settings such feed rate, cutting speed, and depth of cut; (2) elements resulting from cutting-tool characteristics including tool wear, tool shape, material, and coating; (3) workpiece material qualities, including hardness, microstructure, grain size, and inclusions; and (4) variables attributable to machining and machine tool conditions, including dry or wet machining, type of cutting fluid, technique of fluid application, machine tool stiffness, and chatter vibration. Thus, the study of surface roughness at both macroscopic and microscopic levels is important, particularly in machining. Moreover, characteristics such as fatigue strength, wear rate, corrosion resistance, residual stress inclusion, dimensional deviations, white layer, dark layer formation, microhardness of the machined surface, morphological aspects of the machined surface, etc., can all be affected by the surface quality.

This Special Issue aims to encourage the scientists and researchers to present their results in papers related to both experimental and theoretical studies. Specific areas of interest for this Special Issue may include (but are not limited to) the following areas:

• The machining of hard and difficult-to-cut materials using advanced coated tools.
• The machining of hard and difficult-to-cut materials using advanced coated tools.
• The machining of super alloys using carbide, ceramic, CBN, PCBN, and PCD inserts.
• The assessment of tool life and various surface integrity aspects in different cutting conditions.
• The study of tool wear and various surface integrity aspects in electro discharge machining.
• The study of various wear mechanisms of cutting inserts in hard machining.
• The effect of nanofluids and ionic-liquid-based lubricants on tool life during advanced machining.
• The effect of various textured patterns on tool life assesement in machining.
• Sustainable cooling–lubrication machining for an improvement in tool life.
• Modelling and optimization for machinability improvement.

Dr. Sudhansu Ranjan Das
Dr. Anshuman Das
Guest Editors

Manuscript Submission Information

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• machining
• steel
• super alloys
• coated tools
• tool wear
• surface integrity
• cutting temperature
• cutting fluid
• machining economics
• sustainable machining
• cooling–lubrication in machining
• modelling and optimization