Tracing the Historical Development of Metalworking Fluids
Jeanie S. McCoy
CONTENTS
1.1What Are They?
1.2Current Usage in the United States
1.3History of Lubricants: Evidence for Early Usage of Metalworking Fluids
1.4History of Technology
1.4.1Greek and Roman Era
1.4.2The Renaissance (1450ā1600)
1.4.3Toward the Industrial Revolution (1600ā1750)
1.5Evolution of Machine Tools and Metalworking Fluids
1.5.1Early Use of Metalworking Fluids in Machine Tools
1.5.2Growth of Metalworking Fluid Usage
1.5.3After the Industrial Revolution (1850ā1900)
1.5.3.1Discovery of Petroleum in the United States
1.5.3.2Introduction of Better Alloy Steels
1.5.3.3Growth of Industrial Chemistry
1.5.3.4Use of Electricity as a Power Source
1.5.4Early Experimentation with Metalworking Fluids
1.5.5Status of Metalworking Fluids (1900ā1950)
1.5.5.1Development of Compounded Cutting Oils
1.5.5.2Development of Soluble Oils
1.5.5.3Influence of World War II
1.5.5.4Mechanisms of Cutting Fluid Action
1.5.5.5Metalworking Fluids and the Deformation Process
1.6Metalworking Fluids Today
References
1.1 WHAT ARE THEY?
Metalworking fluids are best defined by what they do. Metalworking fluids are engineering materials that optimize the metalworking process. Metalworking is commonly seen as two basic processes: metal deformation and metal removal or cutting. Comparatively recently, metal cutting has also been considered a plastic deformation processāalbeit on a submicro scale and occurring just before chip fracture.
In the manufacturing and engineering communities, metalworking fluids used for metal removal are known as cutting and grinding fluids. Fluids used for the drawing, rolling, and stamping processes of metal deformation are known as metalforming fluids. However, the outcome of the two processes differs. The processes by which the machines make the products, the mechanics of the operations, and the requirements for the fluids used in each process are different.
The mechanics of metalworking govern the requirements demanded of the metalworking fluid. As all tool engineers, metalworking fluid process engineers, and machinists know, the fluid must provide a layer of lubricant to act as a cushion between the workpiece and the tool in order to reduce friction. Fluids must also function as a coolant to reduce the heat produced during machining or forming. Otherwise, distortion of the workpiece and changed dimensions could result. Further, the fluid must prevent metal pickup on both the tool and the workpiece by flushing away the chips as they are produced. All of these attributes function to prevent wear on the tools and reduce energy requirements. In addition, the metalworking fluid is expected to produce the desired finish on an accurate piece-part. Any discussion of metalworking fluid requirements must include the fact that the manufacturing impetus since the days of the Industrial Revolution has been to machine or form parts at the highest rate of speed with maximum tool life, minimum downtime, and the fewest possible part rejects (scrap), all while maintaining accuracy and finish requirements.
1.2 CURRENT USAGE IN THE UNITED STATES
The number of gallons of metalworking fluids produced and sold in the United States represents a significant slice of the gross national product, as indicated in a 2013 report. Of the 2400 million gallons of total lubricant demand in the United States, 141 million gallons were metalworking fluids.1
Kline & Company reported the global annual demand for metalworking fluids in 2012 was 2.2 million tons, or approximately 525 million gallons (1.987 billion liters), worldwide. Of this amount, 49% were for metal removal, 30% for forming, 12% for metal protection, and 9% for metal treating. The largest demand (42%) was in Asia, 28% in North America, 26% in Europe, and 4% in the rest of the world.2
These statistics indicate the importance and wide usage of metalworking fluids in the manufacturing world. How they are compounded, used, and managed and how they impact health, safety, and environmental considerations will be described in subsequent chapters. This chapter will take the reader through the history of the evolution of metalworking fluids, one of the most important and least understood tools of the manufacturing process.
It is surprising that it is not possible to find listings for metalworking fluids in the available databases. The National Technology Information Service, the Dialog Information Service, the well-known Science Index, the Encyclopedia of Science and Technology Index, and the Materials Science Encyclopedia all lack relevant citations. The real story appears to be buried in technical magazines written by engineers and various specialists for other engineers and specialists, and is obscured in books on related topics. Clearly, this is an indication that this information needs to be collected and published.
1.3 HISTORY OF LUBRICANTS: EVIDENCE FOR EARLY USAGE OF METALWORKING FLUIDS
The histories of Herodotus and Pliny, and even the scriptures, indicate that humankind has used oils and greases for many applications. These include lubrication uses such as hubs on wheels, axles, and bearings, as well as nonlubrication uses such as embalming fluids, illumination, the waterproofing of ships, the setting of tiles, unguents, and medicines.3 However, records documenting the use of lubricants as metalworking fluids are not readily available. Histories commonly report that man first fashioned weapons, ornaments, and jewelry by cold working the metal; then, as the ancient art of the blacksmith developed, by hot working the metal. Records show that animal and vegetable oils were used by early civilizations in various lubrication applications. Unfortunately, the use of lubricants as metalworking fluids in the metalworking crafts is not described in those early historical writings.4
Reviewing the artifacts and weaponry of the early civilizations of Mesopotamia, Egypt, and later the Greek and Roman eras on through the Middle Ages, it is obvious that forging and then wire drawing were the oldest of metalworking processes.5 Lubricants must have been used to ease the wire-drawing process. Since metalworking fluids are, and always have been, an important part of the process, it may not be unreasonable to presume that the fluids used then were those that were readily available. These included animal oils and fats (primarily whale, tallow, and lard), as well as vegetable oils from various sources such as olive, palm, castor, and other seed oils.6 Even today, these are used in certain metalworking fluid formulations. Some of the most effective known lubricants have been provided by nature. Only by inference, since records of their early use have not been found, can we speculate that these lubricants must have been used as metalworking fluids in the earliest metalworking processes.
1.4 HISTORY OF TECHNOLOGY
1.4.1 GREEK AND ROMAN ERA
The explanation for the lack of early historical documentation might be found by examining the writings of the ancient Greek and Roman philosophers on natural science. It is readily seen that there was little interest among the āintelligentsiaā for the scientific foundations of the technology of the era.
As Singer points out in his History of Technology, the craftsman of that era was relegated to a position of social inferiority because knowledge of the technology involved in the craft process was scorned as unscientific. It was neither studied nor documented, evidently not considered as being worthy of preservation.7 Consequently, the skills and experience of the craftsman became valuable personal possessions to be protected by secrecy; the only surviving knowledge was handed down through the generations.8
1.4.2 THE RENAISSANCE (1450ā1600)
During the Renaissance, plain bearings of iron, steel, brass, and bronze were increasingly used, especially da Vinciās roller disk bearings in clock and milling machinery as early as 1494; Agricola confirmed the wide use of conventional roller bearings in these applications.9 Although machines were developed to make these parts, there is no record that any type of metalworking lubricant was used in bearing, gear, screw, or shaft manufacture. It is possible that those parts that were made of soft metals such as copper and brass did not require much, if any, lubrication in the manufacturing process, but it would seem logical th...