What Are The Common Machining Processes For Titanium Alloys?

What are the common machining processes for titanium alloys?

Due to its high specific strength and good corrosion resistance, the use of titanium alloys in the aerospace and medical implant fields continues to grow. However, many factories have repeatedly encountered troubles during turning and boring. The three problems of high cutting temperature, rapid tool wear, and large chip rebound have caused many operators extreme headaches. In fact, as long as the appropriate processing conditions are controlled, turning and boring are not as difficult as rumored.

Carbide tools are preferred for continuous cutting

For continuous cutting of titanium alloy parts or titanium alloy parts for mass production, as well as titanium alloy parts with large amounts of metal removal, carbide cutting tools will be the preferred choice for most factories. This material has the ability to withstand higher cutting temperatures and maintain a stable cutting edge at high speeds. There is an aviation parts factory in Jiangsu that conducted actual measurements at the end of 2025. It used carbide tools to turn TC4 titanium alloy, and finally found that the tool life was increased by 5 times compared with high-speed steel.

When intermittent processing such as forming cutting, grooving or cutting is required, high-speed steel cutting tools have more advantages. High-speed steel has better toughness and can withstand impact loads during cutting. There is a medical device company in Shenzhen. When processing the undercut grooves of titanium alloy bone screws, the chipping rate was reduced by 80% after switching to high-speed steel tools.

Applicable scenarios for cermet tools

In titanium alloy finishing, cermet cutting tools are being used more and more, especially in those situations where good surface finish is required. This kind of tool has the characteristics of high hardness for boring processing , and its friction coefficient is also low for boring processing , which can effectively reduce the heat accumulation in the cutting area. A precision machinery factory in Chengdu used cermet tools to boring titanium alloy thin-walled sleeves during the test in January 2026, and the surface roughness reached Ra0.8 microns.

However, cermet cutting tools are relatively sensitive to cutting parameters and are not suitable for heavy-duty roughing. Its bending strength is lower than that of cemented carbide, and if the feed rate is too large, it will easily cause the cutting edge to peel off. Therefore, it is recommended to use it in the finishing stage. The cutting speed needs to be controlled in the range of 40 to 60 meters per minute, and the feed per revolution cannot exceed 0.08 mm.

Forced feed and cutting parameter selection

Always use a constant forced feed method to prevent any kind of cutting interruption. This is one of the core principles of titanium alloy processing. If a sudden stop or deceleration occurs during the cutting process, the tool will rub on the hardened surface, immediately producing very high temperatures and severe tool wear. When programming, the operator should ensure that there are no pause points in the entire tool path.

Before forging, the oxygen-rich layer on the surface of the original bar needs to be turned, which requires the use of carbide tools, and the cutting depth must be greater than the thickness of the oxygen-rich layer. In actual production, the depth of the oxygen-rich layer of titanium alloy bars is generally between 0.3 and 0.5 mm, so the cutting depth of the first knife is recommended to be set at 0.8 to 1.0 mm. The recommended cutting speed is 20 to 30 meters per minute, and the feed rate should be controlled at 0.1 to 0.2 mm per revolution.

The correct method of cooling and lubrication

Do not use dry cutting when turning and boring titanium alloys. Sufficient cooling must be carried out. The purpose of cooling is to take away the cutting heat, reduce the adhesion between the tool and the chips, and prevent titanium chips from forming built-up edge on the rake face of the tool. Many workshops have found that when the coolant supply is insufficient for boring processing , the wear of the tool flank surface will accelerate rapidly.

It is recommended to use two coolants, one is a 5% sodium nitrate aqueous solution, and the other is a soluble oil emulsion diluted to 1/20. Sodium nitrate solution can effectively inhibit the chemical reaction between titanium and tool materials, and soluble oil emulsion has better lubrication performance. The coolant flow rate should reach 15 to 20 liters per minute and must be sprayed directly into the cutting area, not just poured on the left chips.

Tips for preventing burning and deformation during boring processing

In titanium alloy finishing, boring is an important process, especially for thin-walled products. It shoulders two key tasks, namely preventing burns and ensuring that parts are clamped without deformation. Thin-walled titanium alloy parts have poor rigidity. If the clamping force is too large, the workpiece will be out of round. After boring, the dimensions will exceed the tolerance range due to springback. When processing titanium alloy thin-walled shells, an aerospace company in Shanghai used low-stress soft claws and axial compression methods to successfully control the clamping deformation within 0.01 mm.

Rely on controlling cutting heat and sufficient cooling to prevent burns. During boring, the cutting speed should not be too high. The recommended value for rough boring is twenty to twenty-five meters per minute, and the recommended value for fine boring is twenty to twenty meters per minute. Five to thirty meters, the boring tool needs to use a blade with a sharp positive rake angle, and ensure that the arc radius of the tool tip does not exceed 0.2 mm. After each part is processed, check whether the cooling nozzle is aligned with the position of the boring tool tip.

Details that are easily overlooked in actual production

An invisible killer in titanium alloy processing is that the cutting springback is very large and the elastic modulus of the material is low. The machined surface will rebound outward during cutting, which causes continuous friction between the flank surface and the workpiece. The heat generated by this friction is more concentrated than the chip deformation heat, which accelerates the bonding wear and diffusion wear of the tool. To solve this problem, the clearance angle must be kept small enough and a sharp cutting edge must be used.

When machining, try not to cut, but maintain sufficient cooling. This statement is easily misunderstood. The correct understanding is that do not stop cutting to clean the chips. Use high-pressure coolant to directly wash away the chips. The cutting speed, feed rate and The three cutting depths must be matched reasonably. A proven starting parameter is that the cutting speed is 25 meters per minute, the feed is 0.12 mm per revolution, and the cutting depth is 1.5 mm, and then fine-tuned according to the tool wear.

What are the common machining processes for titanium alloys when turning titanium alloys? , what is the most troublesome and difficult tool wear problem you have ever encountered? When boring titanium alloys, what is the most difficult and particularly difficult tool tip wear condition you have encountered? Welcome to share the parameters you use during processing and the processing methods you adopt in the comment area. The three friends with the highest likes will receive an electronic version of the titanium alloy processing manual.