Cutting Wear Phenomenon in Processing
Introduction
Cutting wear is a phenomenon that occurs during machining processes and is one of the most common issues in engineering. The wear process leads to increased tool costs, decreased quality, reduced machine uptimes and increased costs in terms of lost production time. It is very important to understand the different types of wear, their causes and effects, as well as to identify efficient means of reducing the wear of cutting tools.
Definition of Cutting Wear
Cutting wear is the gradual removal of material from the cutting tool as a result of the process of cutting. It is most commonly seen in the form of clogging, abrasion, adhesion and surface fatigue damage. The wear of the cutting tool can severely affect the accuracy of machined components, leading to lost time and money for the manufacturer.
Causes of Cutting Wear
Cutting wear is caused by a variety of factors, and it is important to identify the key causes in order to effectively reduce wear. The main factors leading to wearing of cutting tools can be divided into two categories: process parameters and tool design. Process parameters include temperature, feed rate, cutting speed and lubricant, while tool design components include rake angle, cutting edge radius, coatings and material properties of the cutting tool.
Temperature has a direct correlation with the wear of cutting tools. High temperatures lead to an increase in material wear and reduced tool life. Therefore, it is important to maintain desirable temperatures during machining, as it can help reduce tool wear.
Feed rate is another factor that affects the wear of cutting tool. Feed rate can cause stress to the cutting edge, which leads to increased wear. High feed rates can also cause the temperature of the cutting edge to rise, leading to accelerated wear.
The cutting speed is also a cause of cutting wear, as it plays an important role in the laying down and displacement of material around the cutting edge. Too high of a cutting speed can cause the material being cut to stick to the cutting edge due to increased temperatures, leading to increased cutting tool wear.
The lubricant being used can significantly affect the wear of cutting tools. The type of lubricant should be selected carefully as some can cause the cutting tool to wear at a faster rate.
In addition, the shape of the cutting tool can also affect its wear. The rake angle of the cutting tool affects the forces that are applied to the cutting edge, and too steep of an angle can lead to increased wear due to excessive loading. The material of the cutting tool also affects its wear. Some metals, such as high carbon steels, are prone to wear due to their soft nature.
Effects of Cutting Wear
The effects of cutting wear can be seen in the form of scale and built-up-edges on the machined surface, poor surface finish, poor dimensional accuracy and poor dimensional stability. Wearing of the cutting tool can also lead to an increase in vibrations, which can severely affect the quality of the machined components.
Reducing Cutting Wear
Cutting wear can be reduced through a variety of methods, the most effective being to properly adjust the process parameters and optimize the tool design. Keeping the temperature to a minimum during machining can help reduce tool wear, as well as using an appropriate feed rate and cutting speed. It is also important to select an appropriate lubricant that is suitable for the material being cut.
In terms of tool design, it is important to choose the correct rake angle and cutting edge radius. It is also beneficial to use high-quality materials such as coated carbide and diamond for the production of cutting tools.
Conclusion
Cutting wear is a phenomenon that occurs during machining processes and is one of the most common issues in engineering. It is very important to understand the different types of wear, their causes and effects, as well as to identify efficient means of reducing the wear of cutting tools. Properly adjusting process parameters, optimizing the tool design and using high quality materials can help drastically reduce the wear of cutting tools.
