Development of tool geometry

Significant differences between the specifications of the grinding wheels can also be observed on the rake face. Although the feed rates between VF = 10 mm / min and 50 mm / min are very small, the difference in the surface quality between the wheel specifications is significant for the feed speed VF = 90 mm / min. At this point of operation, the best surface quality of ceramic bond wheel is produced, while the highest ten point roughness Rz is produced based on metal / resin mixed grinding wheel. The explanation for this can be indicated by the grinding force. Increasing the specific normal force F'n may be a sign of higher friction, which is probably due to the structure and structure of vitrification.

The milling test is carried out on the 3 axis milling machine 10V HSC of Dresden Mikromat company. The milling force is recorded by 9257A in the 3 component measurement system of Kistler Instrumente AG of Switzerland Winterthur.

 

Based on the geometric characteristics of the tools evaluated in the preliminary investigation, the geometric characteristics of the end mills are different. For all test geometries, the tool diameter is a constant D = 8mm, while other related tool geometric parameters spiral angle, the number of teeth Z, the depth TN of the slot, and the front angle and the rear angle alpha are changed. Table 3 outlines the various geometric features.

In Figure 4, the feed force Ff of thirteen test tool geometries during circumferential milling is shown. For each geometric shape, two identical end mills enter the milling process, and the milling force is evaluated after Lc = 3.5m tool life path. Regarding the feed force, we can see the clear correlation between the tooth number Z and the clearance angle alpha. It can be seen that the optimized tool geometry shows a relatively minimum feed force. In addition to the analysis of milling force, the working results and wear behaviors were also taken into consideration, so as to develop optimized tool geometry.