What are the reasons for the fast wear of cutting tools for machining?
August 06, 2022
The development of modern technology has continuously led to the development of CNC machining equipment, and has also greatly promoted the advancement of cutting technology. With the continuous improvement of production technology requirements and the constant approach of automation, the material of the tool has begun to change. Tools such as titanium alloy, carbon fiber composite material and super heat-resistant alloy have emerged, which has continuously improved the quality of the tool. Key factors such as reliability, accuracy and longevity of the tool have also been greatly developed and improved.
1, tool wear form
In machining, the tool will wear out after a period of use, and the specific performance of the wear has the following three forms:
1. Losses that occur under mechanical action, such as abrasive wear or chipping;
2. Bonding and diffusion caused by high heat generated during cutting;
3. The cutting edge is softened and melted by the intrusion of chemical raw materials.
Next, we analyze the causes of these three forms of loss one by one:
(1) Causes of wear under mechanical action
When cutting difficult-to-machine materials, tool wear is very likely to occur. This is because most difficult-to-machine materials have low thermal conductivity, which affects the high temperature of the adhesive in the tool material. The bond strength in the state is lowered, thereby accelerating tool wear.
(2) Wear caused by excessive tool temperature
When cutting high-toughness and high-hardness materials, the cutting edge temperature of the tool is generally high, which will cause the tool to wear. Especially in the case of cutting short scrap scraps, there is a crescent wrinkling in the vicinity of the cutting edge, which causes the cutter to wear out in a very short time.
(3) Wear caused by chemical raw materials
For a tool, certain special components in the composition material will produce a wonderful chemical reaction with the composition of the processed material in a specific situation, causing the tool coating to fall off or even become another chemical. This phenomenon accelerates the tool. The occurrence of chipping, wear and the like.
2, the performance requirements of the tool
(1) Abrasion resistance
The current range of cutting tools varies widely, and the materials that make up the tool vary widely, from the worst white steel knives to the best diamond tools. The difference in performance between them is even more subtle.
(2) Impact resistance
A good tool needs to have good impact toughness. For tools that cut in high-speed environments, they also need excellent thermal and chemical stability.
(3) Service life
The current tool, a little better, will coat the tool with a layer of heat-resistant, high-hardness layer material or even a multi-layer coating, just to increase the cutting range of the tool and increase the tool life.
3, tool materials
(1) alloy tool steel
For alloy tool steels, it is common to have high heat hardness, and at the same time, the price is civilian, often used to make complex tools such as reamers, taps and other low-speed tools.
(2) High speed tool steel
High temperature, high hardness and high wear resistance are the advantages of high-speed tool steel. At the same time, due to its good heat treatment performance, it has high strength and good sharpness. It is often used to make forming turning tools, milling cutters, drill bits, etc. Machine tool.
(3) Cemented carbide
This is an alloy made of materials such as carbide, titanium carbide, cobalt, etc. by powder metallurgy. At present, cemented carbide has become one of the most mainstream tool materials.
