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Metalworking Fluids
Published in Leslie R. Rudnick, Synthetics, Mineral Oils, and Bio-Based Lubricants, 2020
William L. Brown, Richard G. Butler
Metalworking is the shaping of a metallic workpiece to conform to a desired set of geometric specifications. Metalworking can be divided into two basic categories, cutting and forming. In cutting operations, the blank is shaped by removing unwanted metal in the form of discrete chips. Cutting operations include turning, tapping, milling, broaching, and grinding. Metal forming processes involve the plastic deformation of the workpiece into a desired shape. Drawing, hot and cold rolling, stamping, and forging are examples of metal forming operations.
Introduction
Published in Xin Min Lai, Ming Wang Fu, Lin Fa Peng, Sheet Metal Meso- and Microforming and Their Industrial Applications, 2018
Xin Min Lai, Ming Wang Fu, Lin Fa Peng
In metal forming, the plastic deformation of raw materials in the form of blank or billet with different geometries and shapes, including plate, sheet, bar, rod, block, wire, tube, etc., is conducted, and the material block or sheet is deformed into desirable geometries without the change of mass and composition of the materials [2–5]. The deformation of materials can be classified into two types of forming processes, viz., bulk and sheet metal forming. The bulk forming refers to the deformation of three-dimensional material block into the deformed parts and components with a specific volume. Bulk metal forming includes forging, extrusion, rolling, drawing, etc., which is used to prepare material preforms and net shape or near-net shape parts and components. Sheet metal forming refers to the metal working process to deform or stamp sheet metals into sheet metal parts and components with specific geometries, dimensions, and tolerance and quality requirements. In sheet metal forming, the surface of the sheet plays an important role, and the interfacial interaction between the sheet metal and tooling surfaces affects process performance and the quality of deformed parts. The main forming operations include shearing, drawing, bending, and forming. In detail, each operation can have its detailed subset operations. Shearing can have more detailed shearing-based operations such as blanking, punching or piercing, notching, and trimming. Forming can also have its subset operations including stretch forming, flexible die forming, bulging, spinning, peen forming, superplastic forming, etc. [2].
Machining and Other Metalworking Operations
Published in E. Higgins Thomas, Hazardous Waste Minimization Handbook, 2018
In machining, a cutting tool or abrasive materials removes metal from a metal workpiece to produce a desired shape and dimension. Thus, machining is but one aspect of metalworking, which includes sawing, milling, grinding, drilling, boring, reaming, turning, stamping, forging, shaping, and heat treating.
A review on sustainable alternatives for conventional cutting fluid applications for improved machinability
Published in Machining Science and Technology, 2023
D. J. Hiran Gabriel, M. Parthiban, I. Kantharaj, N. Beemkumar
Metalworking machine operators were directly exposed to the cutting fluid while operating. Many investigators in their work conclude that direct exposure and permanent contact with these metalworking fluids and their by-products lead to skin diseases, pulmonary diseases, and sometimes even cancer (Hannu et al., 2013; Do et al., 2018; Bryngelsson et al., 2021). Cracks in skin or wounds, when exposed to additives present in cutting fluid such as sulfite and chlorine, will irritate the exposed area. Metalworking machine operators need to use protective gloves, boots, and masks while operating the machine. The Occupation Safety and Health Administration (OSHA) commissioned a committee under Camargo. The committee recommends that the worker should not be exposed to more than eight hours of work with a maximum particle mass of not exceeding 0.4 mg/m3 of total particulate mass in the environment. It also stated the usage of cutting fluids should be limited to ensure workers’ safety. The committee also recommends the usage of proper ventilation systems, and fluid control systems, and should also conduct regular medical camps to facilitate the workers. The National Institute of Occupation Safety and Health (NIOSH) reported that due to the increased concentration and toxicity of cutting fluids, more than one million metalworking operators were at direct risk of bronchitis and skin cancer (Bryngelsson et al., 2021). The negative effects of cutting fluid is listed in Figure 2.
Deformation-induced changes in single-phase Al-0.1Mg alloy
Published in Philosophical Magazine, 2018
Deformation at high temperatures leads to microstructural changes in metallic materials commonly ascribed to dynamic restoration processes. Dynamic recovery and dynamic recrystallisation lower the flow stress and allow materials to deform more easily. An important application of this large area of study is metalworking processes, such as hot rolling, extrusion and forging. The high stacking fault energy of aluminium and its alloys facilitates the occurrence of dislocation climb and cross-slip to occur. Early stages of deformation are characterised by an increase in the dislocation density with a subsequent increase in more organised dislocation arrangements in the microstructure, such as low-angle grain boundaries and subgrains. At this stage, dynamic recovery is the dominant form of dynamic restoration [1]. High-temperature deformation may also produce high-angle grain boundaries (HAGBs) by dynamic recrystallisation. This phenomenon is common for materials with a low or medium stacking fault energy, but it can also occur in aluminium when a critical deformation condition is reached. A substructure with low-angle grain boundaries, formed during deformation due to efficient dynamic recovery, progressively evolves into HAGBs at larger strains [2]. In this case, new grains originate at pre-existing grain boundaries or nucleate intragranularly for low strain rates.