The Ultimate Guide to Metal Cutting Tool Durability
In the mechanical processing tools industry, metal cutting tools are an important factor determining product quality as well as cost. Therefore, processing workshops seek to focus on optimizing the durability of metal cutting tools and minimizing the wear and tear of these tools.
The following article will help you discover what you need to know about the durability of cutting tools as well as the causes of wear and tear.
1. What is metal cutting processing?
Metalworking is one of the methods of making machine parts widely used when making mechanics. This mechanism helps to remove from the surface of the shavings a layer of metal to form parts of the size, shape, precision and smoothness required by each type. Whether the result is achieved with high accuracy depends on the capabilities and technical level of the equipment.
In addition, the method of using metal cutting tools is carried out at normal ambient temperatures. These results are higher than other forms of processing such as welding, forging, casting, or hot stamping. Thereby not only improving the surface quality of machined parts but also contributing to increasing labor productivity and economic efficiency of product production.
Machining metal cutting tools is completely possible with turning cutters, milling cutters, drill bits, grinding wheels or on metal machines. In particular, in mechanical companies, metal cutting machines gradually become more familiar and popular. The reason is that they are able to create movements according to the principle suitable for the cutting process. From that principle, it is possible to create the most accurate metal part.
2. What is the durability of metal cutting tools?
The durability of a machining tool is the continuous working time of that tool between sharpening. In other words, it is the working time calculated from the beginning until the moment the tool wears out to the permissible wear.
The allowable amount of wear will depend on the rough or fine machining method when determining the tool strength according to the front and back. The cutting mode, especially the cutting speed and the amount of tool running, will be the factor that most affects the durability of the metal cutting tool. There are types of tool abrasion that can be mentioned as follows.
2.1. Back abrasion
Back abrasion usually occurs when machining with small cutting thickness, for brittle types of machined materials.
2.2. Front abrasion
Front abrasion appears when cutting due to sliding chips forming a pressure center some distance from the cutting edge. This interval has a crescent-like shape due to the tool material being peeled off during movement. Indentations usually appear along the cutting edge and are judged by the width, depth, and distance from the blade to the wear. This phenomenon occurs when processing using metal cutting tools with a large depth.
3. Why should you focus on the durability of metal cutting tools?
The durability of mechanical cutting tools greatly affects productivity and economic factors in machining. Depending on the technical requirements of the machined part, it will affect the durable life of the metal cutting tool.
The coating on cutting tools has a great effect on reducing friction, reducing temperature extremely well. Besides, the development of the temperature field in the tool leads to reduced temperature wear and increased durability. In particular, this coating helps prevent sticking, mechanical scratches help reduce wear.
Experimental methods can determine the durable age of cutting tools, and this is often influenced by the following reasons:
· The change in hardness, microstructure, chemical composition and surface characteristics of the workpiece.
· Mechanical changes in tool materials, geometric parameters and grinding methods.
· The fluctuation of the system of machines and tools for metal cutting.
4. Causes and mechanisms causing abrasion
Abrasion of metal cutting tools is a complex process caused by the simultaneous action of mechanical and thermal stress of the cutter. Abrasion of metal pipe cutting tools also occurs with physicochemical phenomena in the contact area between the cutting tool and the chip. This operation can damage the tool, adversely affecting the machining process for the following prominent reasons.
4.1 Wear due to scratches
Abrasion due to scratching is a mechanism that occurs when cutting metal at low speed and heat. The essence of the wear process is that particles of impurities of high hardness in the machined material and chips scratch (abrade) the contact surfaces of the cutting tool with the part and chip.
Abrasion occurs when the front and back of the metal cutting tool have hard particles splashed from the workpiece peeling away the material element. From there, a scratch is formed parallel to the way of draining the embryo. The greater the hardness of the sides in contact with the tool, the higher the degree of scratching. When the knife is built-up edge, some elements will cause abrasion on the back of the cutting tool.
4.2 Wear due to adhesive melting
This is caused by adhesion between the processing material and the cutting tool material. When solid surfaces slide against each other, abrasion due to adhesive flow occurs at the contact site at the top.
When sliding, the material in this area is sliding adhering to the opposite surface or may form discrete wear fragments. Others are also produced by fatigue-induced wear at the top of the undulations. The machining process encounters great pressure on the contact surfaces, causing the plastic melted material element to stick to the chips, causing knife wear.
4.3 Oxidative wear
The nature of the cause of wear due to the peeling of the oxidizing layer. During high-temperature processing, the surface layers, materials, metal cutting tools may oxidize. Poor strength is easy to destroy and causes abrasion.
The oxidation layer is formed in a continuous succession process when the old oxidation layer is peeled off. This film is able to prevent adhesion. When working in a vacuum environment, birth wear may occur due to the inability of an oxidizing film to form.
4.4 Wear due to diffusion
This phenomenon occurs when there is a chemical similarity between the machined material and the cutting tool material. Therefore, the elements will diffuse into the chips and the processing material will cause wear on the cutting edge. The high temperature developed in the tool when cutting is a favorable condition for the diffusion process between the tool and machining.
4.5 Heat wear
This is a possible cause of overheating of metal cutting tool materials because the volume of material at the cutting edge is very small when the temperature is concentrated on the cutting site. This in turn results in the cutting edge being destroyed by heat. To minimize this phenomenon, you can use blade coolant when machining.
5. Tips to increase the service life and durability of CNC cutting tools
Here are 6 great tips to help you increase the service life and durability of your CNC cutting tools.
5.1 Proper use of coatings
Using hard coating helps to make the machined surface quality better, enhancing the wear resistance of metal CNC cutting tools. In addition, using the coating also increases surface lubrication, reducing friction forces, increasing tool life.
5.2 Choose the right metal cutting tool for each raw material and product to be machined
It is recommended to choose the right knife for the original work to increase the durability of the knife. Each workpiece, each product has a different hardness material, so it is necessary to choose a metal cutter suitable for the material and hardness of that product.
5.3 Temperature control when machining
During processing, friction between the knife and the shavings generates a lot of heat, care should be taken to reduce heat for the tool. We can use liquid CO2 directly when cutting or use cooling, cooling irrigation oil to reduce the temperature and extend the life of the tool.
5.4 Chip release control
Controlling the flow of chips released during machining will help minimize damage to the tool.
5.5 Blade cleaning
The blade should be cleaned periodically, this is also the time to review the blade damage and consider replacing it if necessary. Many methods can be used to clean the cutting blade such as using a brush to clean, sweep the shavings …
5.6 Use suitable cold irrigation oil
Choosing the right cold irrigation oil will help reduce friction forces when cutting, increasing the durability of metal CNC cutting tools.
6. Conclusions
The above is information related to the durability and wear of metal cutting tools. To learn and expand your knowledge about the field of metal processing, you can attend a large-scale industrial exhibition in Vietnam. Typically, Metalex Vietnam 2024 – one of the biggest events in machine tools and metalworking in our country as well as in Southeast Asia by RX Tradex.
At this exhibition, you will have the opportunity to visit and experience the latest products and solutions from leading companies in the industry. Register to join and discover interesting things at Metalex Vietnam 2024!
