Metalworking Fluids

Abstract

Metalworking fluids (MWFs) constitute very large number of products for a variety of operations involving metal removal such as cutting, grinding, milling, threading, broaching, turning, sawing, drilling, deep hole drilling, boring, tapping, etc. and metal forming such as rolling, drawing, forging, stamping, and forming of different metals. For each of these operations with a particular metal, different fluid is required for a satisfactory product and good tool life. Every manufacturing industry starting from a small workshop with a lathe machine to a large automobile unit carrying out sophisticated operations needs these fluids. There is also equally large number of small and big organized manufacturers and suppliers of MWFs that it is not known how much quantity of these fluids are manufactured [1]. Through these operations, a crude metal piece is shaped into desired geometric specifications. Metalworking operations can be broadly divided into two categories: metal removal processes and metal-forming processes. The MWF plays the important role of removing heat and providing lubrication between the tool and workpiece. These fluids are thus referred to coolant as well. In industry, there are also several metal removal operations that are carried out under dry condition without using a coolant. However, the use of coolant is more prevalent to get a good-quality workpiece and extended tool life. MWFs are neat oils or water-based fluids/emulsions used during the machining and shaping of metals to provide both lubrication and cooling. In addition, these fluids must protect metals from corrosion and should be able to remove metal chips formed during the operation effectively. These machining operations are such that the exposure of these fluids to the human being cannot be completely avoided. MWFs are mostly applied by jet, spray, or hand dispenser, and generate mist during the operation, which can be inhaled by the operators. The fluids also come in direct contact with skin, specially hands and forearms. Consequently, there are several health risks involved in the applications of MWFs, which in turn restrict the use of hazardous chemicals in MWFs; even the selection of base oils is important from the point of health risks.The main health risks from MWFs are irritation of the skin or dermatitis, irritation of the upper respiratory tract, breathing problems, allergies, and occupational asthma. Similar risks are also involved with any fluids used for washing machines and equipment. Metalworking industry is therefore unique in the sense that the methodology required to develop MWF is quite different than the methodology followed for the development of industrial oils or automotive oils. In addition, there are no well-defined specifications with test methods to evaluate MWFs. These products remain performance Chapter 16 METALWORKING FLUIDS