Yes, Titanium is still can be CNC machined, but not easy. Why? Because the titanium material is rigid and brittle, so Titanium cannot be machined as easily as steel, brass, bronze, or aluminum. The chip produced during machining tends to break off easily. Speeds and feeds for machining titanium should be selected with care.
Why is CNC Machining Titanium Difficult?
Titanium is 8 to 10 times harder than steel and 5 to 9 times harder than stainless steel.
Titanium tends to work harden. Hardness is resistance to localized plastic deformation. When titanium is machined, it work hardens. The harder it gets, the more it chips.
Titanium has a lower thermal conductivity. High thermal conductivity is necessary for rapid chip evacuation. So it requires special tooling, fixturing, and work holding, as well as knowledge of the machining characteristics and proper speeds and feeds.
What grade of titanium is easiest to machine?
Grade 2 titanium is easy to work with, but one must be careful with the type of coolant used. The surface of the material must be absolutely clean. Therefore avoid using any coolant that may leave an oily residue on the surface, as this could cause adhesion problems.
When machining titanium, it is good to use a higher spindle speed (200–2,000 RPM). This will prevent the tool from overheating and delaminating from the titanium. Remember to cut slowly and use a sharp tool, either carbide or HSS.
What grade of titanium is hardest to machine?
Grade 7 titanium is tough to work with, and abrasive cutting technology must be used. This grade is best machined between 1,500 and 3,000 RPM, but spindle speeds between 3,000 and 4,000 RPM are advised. An HSS tool should be used, and sharp cutting edges are critical. Avoid using coolant that may leave a fine oily residue on the surface.
What grade of titanium is easiest to weld?
Grade 5 titanium is the most accessible grade to weld. Welding parameters should be set at a 28–35 volts voltage, using DCEN polarity. Preheat is required.
Can titanium catch on fire when machining?
Titanium is a reactive metal, when machining titanium it oxidizes easily. Over time this can cause the cutting tool to dull. If the temperatures rise too high titanium can catch on fire.
The temperatures required to ignite titanium is between 25-40 Celsius. For titanium alloys, the temperature is between 450-500 Celsius.
To suppress this, coolants are used. Coolants reduce friction, lubricate, suspend and wash away chips. They can also suppress fire, but this is only effective for a short period. So fire protection is important when machining titanium.
Titanium has long held a reputation for being a problematic and expensive material to machine due to its unique properties. But as titanium parts have become more common, manufacturers have learned procedures and techniques that make CNC machining titanium more efficient and cost-effective.
At Bosetitanium, we know how to overcome the challenges of titanium CNC machining to deliver high-quality products that meet your application and budget needs, so please don’t hesitate to contact us if you want to custom some new products.