Classification of Water-Based Cutting Fluids
Over the years, cutting fluids have been used in machining operations to cool and lubricate the cutting tool and workpiece in order to decrease the cutting forces, improve surface finish of the machined part, and increase tool life. The two main types of cutting fluids used for machining are mineral oil- and water-based. Water-based cutting fluids are further divided into three categories: soluble oils, synthetic fluids and semi-synthetics. Each type of cutting fluid has its own advantages and disadvantages which depend on the specific machining operations that are being performed. In this article, the key characteristics and applications of each type of water-based cutting fluid will be discussed.
Soluble Oils
Soluble oil cutting fluids are the most popular and widely used type of water-based cutting fluids. They are composed of mineral oil, emulsifier and water. These are the most efficient in terms of lubrication and cooling, and they can provide excellent protection against corrosion and rust. Although they are not as stable as synthetics, soluble oils can be effective for a wide range of machining operations including drilling, turning and milling.
Synthetic Fluids
Synthetic fluids are composed of a mix of water, oil and chemical additives. The oil additives used can range from organic esters and polyalkylene glycols (PAG) to synthetics. Synthetic fluids are very stable, free from bacteria and offer excellent lubrication and cooling. However, they can be quite expensive and require frequent additive top ups. Synthetic fluids are generally suitable for difficult machining operations such as deep hole-drilling and grinding.
Semi-Synthetics
Semi-synthetic fluids are blends of soluble oils and synthetics. They offer a good balance between performance, cost and health and safety. They are frequently used for operations such as turning, tapping and reaming, as well as for heavy machining operations that are not suitable for soluble oil or synthetic fluids.
In conclusion, water-based cutting fluids can be divided into three broad categories – soluble oils, synthetics and semi-synthetics. Each type of cutting fluid has its own set of application and performance characteristics, which makes it suitable for certain machining operations. It is important to carefully consider the type of cutting fluid that is most suitable for the machining operations that are being performed in order to obtain maximum efficiency, productivity and cost savings.
