There are many methods for using titanium alloys in mechanical processing, including turning, milling, boring, drilling, grinding, tapping, sawing, electrical discharge machining, etc.

1. Turning and boring of titanium alloy

The main problems with turning titanium alloys are: high cutting temperature; The tool wear is severe; The cutting rebound is large. Under appropriate mechanical processing conditions. Turning and boring are not particularly difficult processes. For continuous cutting, mass production, or cutting with large metal removal, hard alloy cutting tools are generally used. When performing forming cutting, grooving, or cutting, adjusting steel cutting tools are suitable, and metal ceramic cutting tools are also used. Like other machining operations, always using a constant forced feed can avoid cutting interruptions. Do not stop or slow down during the cutting process. Generally, cutting should not be carried out, but sufficient cooling should be carried out; The coolant can be a 5% sodium nitrate aqueous solution or a 1/20 soluble oil emulsion aqueous solution. Before forging, hard alloy cutting tools are used to turn the oxygen rich layer on the surface of the original bar material. The cutting depth should be greater than the thickness of the oxygen rich layer, with a cutting speed of 20-30m/min and a feed rate of 0.1-0.2mm/r. Boring is precision machining, especially for thin-walled titanium alloy products. During boring, it is necessary to prevent burns and deformation of parts during clamping.

2. Drilling and machining of titanium alloys

When drilling titanium alloys, it is easy to generate long and thin curled chips, and the drilling heat is high, which can cause excessive accumulation or adhesion of chips to the drilling edge. This is the main reason for the difficulty in drilling titanium alloys. Short and sharp drill bits and low-speed forced feed should be used for drilling, and the support bracket should be tightened and adequately cooled repeatedly, especially for deep hole drilling. During the drilling process, the drill bit should remain in the drilling state inside the hole and not be allowed to idle in the borehole, and should maintain a low and constant drilling speed. Drilling through the hole should be done carefully. When it is about to be drilled through, in order to clean the drill bit and drill hole, and remove drilling debris, it is best to retract the drill bit. When the hole is finally broken, forced feed should be used to obtain a smooth hole.

3. Tapping of titanium alloy

Tapping of titanium alloy may be the most difficult mechanical machining process. When tapping, the limited removal of titanium chips and severe biting tendency will result in poor thread fit, causing the tap to get stuck or break. When tapping is completed, titanium alloy tends to dry and compact on the tap. Therefore, blind holes or excessively long through holes should be avoided as much as possible to prevent the surface roughness of internal threads from increasing or the occurrence of cone breakage. At the same time, continuous improvement should be made in the tapping method, such as grinding off the trailing edge of the tap. Grind axial chip grooves along the length of the tooth edge at the tooth tip. On the other hand, taps with surfaces treated with oxidation, oxidation, or chrome plating are used to reduce biting and wear.

4. Sawing and processing of titanium alloys

When sawing titanium alloys, low surface speed and continuous forced feeding should be used. Experimental results have shown that high-speed steel saw bars with coarse teeth ranging from 4.2mm to 8.5mm are suitable for sawing titanium alloys. If using a band saw to saw titanium alloy, the tooth pitch of the saw blade is determined by the thickness of the workpiece, generally ranging from 2.5mm to 25.4mm. The thicker the material thickness, the larger the tooth pitch. At the same time, it is necessary to maintain the forced feeding capacity and the required coolant.

5. Electric discharge machining of titanium alloy

The electrical discharge machining of titanium alloy requires an operating gap between the tool and the workpiece. The optimal gap range is 0.005mm to 0.4mm. Smaller gaps are commonly used for precision machining that requires smooth surfaces, while larger gaps are used for rough machining that requires rapid removal of metal. It is best to use copper and zinc as electrode materials.