Ceramic cutting titanium alloy should start from the two aspects of reducing the cutting temperature and reducing the adhesion. It is suitable to choose tool materials with good red hardness, high bending strength, good thermal conductivity, and poor affinity with Machinable Glass Ceramic Sleeve titanium alloys. YG cemented carbide is more suitable. Due to the poor heat resistance of high-speed steel, tools made of cemented carbide should be used as much as possible. Commonly used cemented carbide tool materials include YG8, YG3, YG6X, YG6A, 813, 643, YS2T and YD15.
Coated inserts and YT-type cemented carbide will have a violent affinity with titanium alloys, which will aggravate the bonding and wear of tools, and are not suitable for cutting titanium alloys. For complex and multi-edged tools, high-vanadium high-speed steel (such as W12Cr4V4Mo) ), high-cobalt high-speed steel (such as W2Mo9Cr4VCo8) or aluminum high-speed steel (such as W6Mo5Cr4V2Al, M10Mo4Cr4V3Al) and other tool materials, suitable for making drills, reamers, end mills, broaches, taps and other tools for cutting titanium alloys.
Using diamond and cubic boron nitride as tools for cutting titanium alloys can achieve significant results. For example, the cutting speed can reach 200 m/min under the condition of emulsion cooling with natural diamond tools; if the cutting fluid is not used, the allowable cutting speed is only 100 m/min at the same amount of wear. In the process of cutting titanium alloy, the matters that should be paid attention to are:
(1) Due to the small elastic modulus of ceramics, the clamping deformation and force deformation of the workpiece during processing will reduce the processing accuracy of the workpiece; the clamping force should not be too large when the workpiece is installed, and auxiliary support can be added when necessary.
(2) If a cutting fluid containing hydrogen is used, it will decompose and release hydrogen at high temperatures during the cutting process, which will be absorbed by titanium and cause hydrogen embrittlement; it may also cause high-temperature stress corrosion cracking of titanium alloys.
(3) The chloride in the cutting fluid may also decompose or volatilize toxic gas during use. Safety protection measures should be taken when using it, otherwise it should not be used; after cutting, the parts should be thoroughly cleaned with a chlorine-free cleaning agent Machinable Glass Ceramic Sleeve in time to remove chlorine residues Things.
(4) It is forbidden to use lead or zinc-based alloy tools and fixtures in contact with titanium alloys, and copper, tin, cadmium and their alloys are also forbidden to use.
(5) All tools, fixtures or other devices in contact with the titanium alloy must be clean; the cleaned titanium alloy parts should be prevented from being contaminated by grease or fingerprints, otherwise it may cause salt (sodium chloride) stress corrosion in the future.
(6) Under normal circumstances, there is no danger of ignition when cutting titanium alloys. Only in micro-cutting, the small chips cut off will ignite and burn. In order to avoid fire, in addition to pouring a large amount of cutting fluid, it is also necessary to prevent the accumulation of chips on the machine tool. The tool should be replaced immediately after being blunt, or the cutting speed should be reduced, and the feed rate should be increased to increase the thickness of Machinable Glass Ceramic Sleeve the chip. In case of fire, fire extinguishing equipment such as talcum powder, limestone powder, dry sand should be used to extinguish the fire. Carbon tetrachloride and carbon dioxide fire extinguishers are strictly prohibited, and watering is prohibited, because water can accelerate combustion and even cause hydrogen explosion.
What kind of tools are used to process ceramics?
2021 09/13