Formed cemented carbide milling cutters are widely used because of their small shape tolerances. Because the blades cannot be replaced directly, most of the milling cutters are scrapped after chipping, which greatly increases the processing cost.
1. Processing material properties
When cutting titanium alloys, due to the poor thermal conductivity of titanium alloys, the chips are easy to adhere to the tool tip or the edge of the tool or form a built-up edge. High temperature areas are formed on the front and flank surfaces near the tool tip, causing the tool to lose its hardness and wear. Intensify. In continuous cutting under high temperature conditions, the adhesive and weld are impacted by subsequent processing, and part of the tool material will be taken away in the process of being forced to wash away, resulting in tool defects and breakage. In addition, when the cutting temperature reaches above 600°C, a hardened hard layer will form on the surface of the part, which will cause a strong wear on the tool. Titanium alloy has low modulus of elasticity, large elastic deformation, and large rebound of the workpiece surface close to the flank surface, so the contact area between the processed surface and the flank surface is large, and the wear is serious.
2. Normal wear and tear
In normal production and processing, when the allowance of continuous milling of titanium alloy parts reaches 15mm-20mm, severe blade wear will occur. The efficiency of continuing milling is extremely low, and the surface finish of the machined parts is very poor, which cannot meet the production and quality requirements.
3. Improper operation
In the process of producing and processing titanium alloy casting boxes and lids, improper operations such as improper clamping, inappropriate cutting depth, excessively fast spindle speed, and insufficient cooling can cause tool chipping, breakage, and breakage. In addition to not being able to effectively mill this type of defective milling cutter, it will also cause surface defects such as depressions on the machined surface due to "gnawing the cutter" during the milling process, which not only affects the processing quality of the milled surface, but also causes the machined parts to be scrapped in severe cases.