When the hardness of titanium alloy is higher than HB350, it is particularly difficult to process. When the hardness is lower than HB300, it is easy to stick to the tool and difficult to cut. Therefore, titanium processing problems can be solved from the blade. The blade groove wear that occurs when machining titanium alloys is the local wear of the back and front in the direction of the cutting depth. It is often caused by the hardened layer left over from previous treatment. Chemical reaction and diffusion between tool and workpiece material at processing temperature above 800°C is also one of the causes of groove wear. Because during the machining process, the titanium molecules in the workpiece accumulate in front of the blade and are “welded” to the blade under high pressure and high temperature, forming an accumulated edge. When the built-up edge separates from the cutting edge, it takes the carbide coating on the insert with it. Machining titanium therefore requires special materials and insert geometries.
(1) Use inserts with positive angle geometry to reduce cutting force, cutting heat and workpiece deformation.
(2) Maintain a constant feed to avoid hardening of the part. The tool must always be in a leading state during the cutting process. The radial cutting amount ae should be 30% of the radius during milling.
(3) Use high pressure and high flow cutting fluid to ensure the thermal stability of the machining process and avoid workpiece surface degeneration and tool damage caused by excessive temperature.
(4) Keep the edge of the blade sharp. Dull tools cause heat buildup and wear, which can easily lead to tool failure.
(5) Process titanium alloys to the softest state possible, because the material becomes more difficult to process after quenching, and heat treatment increases the strength of the material and increases blade wear.
(6) Use a large tool tip arc radius or chamfer to insert as much of the tool edge into the cut as possible. This reduces cutting force and heat at all points and prevents local breakage. When milling titanium alloy, among the cutting parameters, cutting speed has the greatest impact on tool life vc, followed by radial tool engagement (milling depth ) ae.
It is worth mentioning that because titanium alloys generate a large amount of heat during machining, a large amount of high-pressure cutting fluid should be sprayed onto the cutting edge quickly and accurately in order to quickly discharge the heat. heat. Nowadays, there are also unique structures of milling cutters specifically used for processing titanium alloys on the market, which can be better suited to processing titanium alloys.
Daguang focuses on providing solutions such as precision CNC machining services (3-axis, 4-axis, 5-axis machining), CNC milling, 3D printing and rapid prototyping services.
