1. 前刀面磨损 2. 后刀面磨损 3. 边界磨损( 前、后刀面同时磨损)
从对温度的依赖程度来看，刀具正常磨损的原因主要是机械磨损和热、化学磨损。机械磨损是由工件材料中硬质点的刻划作用引起的，热、化学磨损则是由粘结（刀具与工件材料接触到原子间距离时产生的结合现象） 、扩散（刀具与工件两摩擦面的化学元素互相向对方扩散、腐蚀) 等引起的。
There are the following types of normal tool wear:
1. Front blade wear 2. Back knife surface wear 3. Boundary abrasion(both front and rear blade)
Judging from the degree of dependence on temperature, the normal wear of the tool is mainly due to mechanical wear and thermal and chemical wear. Mechanical wear is caused by the engraving of hard points in the workpiece material. Heat and chemical wear are caused by adhesion(the combination of the tool and the workpiece material when they come into contact with the distance between atoms), diffusion(the chemical elements of the friction surface between the tool and the workpiece spread to each other, corrosion), etc..
(1) Grinding wear
In the process of cutting, the tool is often carved by some hard points with different depths of groove. The abrasion effect of abrasive grains on high speed steel is more obvious.
(2) Adhesive wear
The binding phenomenon that occurs when the tool and the workpiece material come into contact with the distance between atoms is called bonding. Adhesive wear is caused by the shear failure caused by the sliding of the contact surface at the bond. Glue wear is the main wear cause of cemented carbide tools in low and medium speed cutting.
(3) Diffusion wear
During cutting, under the action of high temperature, the molecular activity energy between the contact surfaces is large, resulting in the diffusion and replacement of alloy elements, which reduces the mechanical properties of the tool material. If the tool is subjected to friction, the tool is easily worn. Diffusion wear is a chemical wear.
(4) Phase change wear
When the maximum temperature on the tool exceeds the material phase temperature, the metallographic structure of the tool surface changes.
(5) Oxidation wear
Oxidation wear is a chemical wear.