Analysis Of Forms And Causes Of Wear In CNC Turning Tool | CNCLATHING

The wear forms and causes of CNC turning tools are mainly divided into the following 3 types:

1. Rake face loss of CNC turning tool

The rake face loss of CNC turning tool is also called crescent wear. The reason is that when cutting plastic materials at a high speed, the rake face is close to the cutting force, and under the action of the force, it is easy to wear into a crescent concave. At the initial stage, the cutting condition can be improved, which is conducive to the chip curling and breaking, because the tool rake angle increases at the initial stage. However, when the crater is further enlarged, the cutting edge strength is greatly weakened, and eventually the cutting edge is broken. When cutting brittle materials or plastic materials with low cutting speed and thin cutting thickness, crater wear usually does not occur.

2. Tool tip wear of CNC turning tool

The wear of CNC turning tool tip is the extension of the wear of the tool flank, which is the flank of the arc of the tool tip and the adjacent flank. This is because the heat dissipation condition of this part is poor and the force is relatively concentrated, so the wear speed is much faster than that of the flank. Sometimes, a series of small grooves with spacing equal to the feed rate are formed on the flank, which is called groove wear. This is mostly due to the hardened layer and cutting lines on the machined surface. When cutting hard cutting materials with high work hardening tendency, it is especially easy to cause groove wear. The wear degree of the tool tip has different influence on the surface roughness and machining accuracy of the workpiece.

3. Flank wear of CNC turning tool

The reason for the wear of the flank of CNC turning tool is that when the plastic material is cut with a large cutting thickness, the chip accumulation is produced, and the flank of the tool may not contact with the workpiece. In addition, when the flank is in contact with the workpiece, a wear band with 0 rake angle will be formed on the flank. In the middle of the working length of the cutting edge, the wear of the flank is relatively uniform, so the wear degree of the flank can be measured by the width VB of the flank wear band of the cutting edge. No matter what type of tool, in different cutting conditions, there will be flank wear, especially when cutting plastic materials or brittle materials with a small cutting thickness. The tool wear mainly comes from the flank. It is easy to measure the width of the wear band VB, so VB is often used to express the degree of tool wear. The larger the V8 is, the easier it is to increase the cutting force, It causes cutting vibration, which affects the wear of the tool tip arc, and finally affects the quality and accuracy of the machined surface.