Dongguan CNC processing plant is here to introduce advanced manufacturing technology suitable for titanium alloy processing, which can greatly improve production efficiency and processing quality-ultra-high-speed cutting.
1): Overspeed cutting characteristics and scope of application
Dongguan CNC processing plant is a breakthrough in the understanding of traditional cutting in the cutting principle of ultra-high-speed cutting. The cutting mechanism is different from conventional cutting. Ultra-high-speed cutting has its own characteristics and scope of application.
a. The temperature rise of the workpiece is small to reduce the thermal deformation of the workpiece
In ultra-high-speed cutting, although a lot of heat is generated, because the chips are cut away from the workpiece at a fast speed, more than 90% of the cutting heat is taken away by the chips, and the heat transferred to the workpiece is very small, and the workpiece accumulates very little heat, so cutting At this time, the temperature of the workpiece will not rise more than 3°C.
b. Low cutting force
Due to the high cutting speed, the Dongguan CNC processing plant narrows the shear deformation zone, increases the shear angle, reduces the deformation coefficient, and the chip flow rate is faster, which can reduce the cutting deformation and the cutting force. It is 30% lower than the conventional cutting force. %～90%, the tool durability is increased by 70%, especially suitable for processing thin-walled workpieces with poor rigidity.
c. High material removal rate and high surface quality
The feed rate of the Dongguan CNC processing plant during ultra-high-speed cutting can be increased by 5-10 times as the cutting speed increases. In this way, the material removal rate per unit time can be increased by 3 to 5 times. In addition, as the cutting speed increases, the chips can be quickly cut away from the workpiece, so the residual stress on the surface is very small. Due to the increase in the temperature of the cutting point, the height of the scale on the surface of the workpiece will be significantly reduced or even disappear completely.
2): Ultra-high speed cutting titanium alloy
Ultra-high-speed cutting of titanium alloy improves its machining performance under the action of high strain rate response, thereby obtaining high machining quality. The speed of ultra-high-speed cutting of titanium alloy is generally controlled in the range of 150-1000m/min. In addition to cutting speed, the key technology for ultra-high-speed cutting of titanium alloys also includes many factors such as tool spindle unit and feed unit manufacturing technology, machine tool support and auxiliary unit manufacturing technology, processing and testing technology. This article focuses on the tool materials that have a great impact on tool durability, machining efficiency and machining quality in the process of ultra-high-speed cutting of titanium alloy, in order to find the best match between the tool and the titanium alloy.
a. Tool materials for ultra-high-speed cutting
Because the ultra-high-speed cutting speed is several times or even ten times higher than the conventional cutting speed, and the cutting temperature is very high, the ultra-high-speed cutting puts forward higher requirements for tool materials. The tool material should have high heat resistance, thermal shock resistance, good high temperature mechanical properties and high reliability. At present, the main tool materials used for ultra-high-speed cutting at home and abroad are: coated cemented carbide, TiC(N)-based cemented carbide, ceramic tools, polycrystalline diamond PCD and cubic boron nitride.
Coated carbide cutting tools Coated cutting tools are coated with one or more layers of refractory compounds with good wear resistance on the tough tool body, so that the tool has both high toughness and high hardness and resistance. Grindability, the service life of coated tools is 2 to 5 times longer than that of uncoated tools.
Polycrystalline diamond tools Natural diamond tools are brittle in nature and easily break along the physical surface of the crystal, leading to large chippings. In many cases, they have been replaced by polycrystalline diamond (PCD). PCD is made by adding graphite as raw material to catalyst and sintering at high temperature and high pressure. It has good thermal conductivity, abrasion resistance and high hardness.
Polycrystalline cubic boron nitride tool Polycrystalline cubic boron nitride (PCBN) is a polycrystalline material obtained by sintering fine cubic boron nitride (CBN) materials together under high temperature and pressure. PCBN tools have the advantages of CBN. , Is also easier to manufacture than CBN, so PCBN has been developed quickly. PCBN has high thermal stability, can withstand cutting temperatures above 1200 ℃, and has high hardness and high wear resistance.
b. Titanium alloy requirements for tool materials
According to the processing characteristics of the titanium alloy material itself, the CNC processing plant in Dongguan requires that the tool material should have high deformation strength, high hardness, good toughness, good thermal hardness, good wear resistance and good heat dissipation.
In addition to the above, because titanium-containing tool materials are easily compatible with titanium alloys at high temperatures, titanium-containing tool materials must not be used.