Use the Right Tools and Equipment
First and foremost, you must ensure that you are using the right tools and equipment for the job. This might sound pretty obvious, but it's a crucial step in any machining process. Titanium alloys are more difficult to machine due to their increased hardness. Always use high-speed steel tools and carbide-tipped bits when cutting titanium. Steel tools will dull quickly when used on this material, while carbide tips cut cleanly and last longer.
Transmit the Generated Heat into the Chip
One important aspect of efficiently machining titanium is transmitting the generated heat into the chip. This helps to keep the workpiece, the tool, and the coolant fluid at a relatively consistent temperature. The most effective way to do this is to use a horizontal spindle machine for titanium machining.
Another thing you can do to transmit the generated heat into the chip is to increase the feed rate for the part. A higher feed rate can help to keep the temperature consistent during the machining process. This can be especially helpful when machining parts with large feature sizes.
Increase Coolant Concentration and Pressure
As mentioned, titanium alloys have a higher heat conductivity than other metals. Therefore, you should increase the coolant concentration and pressure when machining these materials. Increasing the coolant concentration can help reduce the heat that builds up in the machine. It can also help to keep the workpiece and tool at a relatively consistent temperature, allowing you to increase feed rates for the part.
If you are using a water-based coolant, you can increase the concentration of this fluid by adding an antifoaming agent. A good option for an antifoaming agent is sodium salts, which help increase water's boiling point and viscosity.
Avoid Galling
Titanium alloys typically have a lower lubricity than other metals. This means that they are more likely to gall during machining. Galling is a phenomenon that occurs when two opposing pieces of metal come into contact, and one piece becomes trapped between the two. Galling can cause the machining process to become much more difficult and significantly reduce tool life.
You can help to avoid galling when machining titanium alloys by using a smaller feed rate and a lower spindle speed. In addition, if you are already experiencing galling, you can often fix the problem by increasing the coolant concentration. This can help break the existing gall and allow you to continue the machining process.
