90% of the implanted parts of medical parts and devices are made of ti6al-4v titanium alloy, which is light, high strength and high biocompatibility. Titanium alloy 6Al-4V has become the most commonly used material for medical implanted medical parts and devices. Titanium alloy 6Al-4V is usually used in the manufacture of hip joint, bone screw, knee joint, bone plate, implant teeth and spinal connecting elements

Titanium alloy has the property of work hardening. The cutting angle is large, the chip is thin, and a relatively small contact area is formed on the tool. In addition, the high cutting force combined with the friction of chip flow will lead to the high cutting heat of the tool. However, due to the poor thermal conductivity of titanium alloy, the cutting heat can not be transferred quickly. Therefore, a lot of cutting heat is concentrated on the cutting edge and tool surface. High cutting force and cutting heat will cause crater and tool failure.

The relatively low elastic modulus makes titanium alloy more elastic than steel. Therefore, excessive cutting force should be avoided to ensure small rebound of workpiece. Thin walled parts tend to deform under tool pressure, causing chatter, friction and even tolerance problems. The key to solve the problem is to ensure the rigidity of the whole system. It is necessary to use sharp cutting edge and correct geometric tool. In addition, titanium alloy has the tendency of chemical reaction alloying with cutting tools at high temperature, and its chips have the tendency of welding to the tool surface.

Medical device processing equipment needs to be able to process small and complex parts made of difficult to process materials (such as titanium alloy or stainless steel) with high precision requirements, such as processing bone and joint substitutes. Due to the poor machinability of the material to be machined, the blank is usually a bar stock - which means that a large amount of metal needs to be removed. As a result, some of the parts are cast into a shape close to the finished product, but this also adds to the trouble of making complex and expensive fixtures. Another factor that increases the complexity of machining is the narrow tolerance range.

Medical device parts have high requirements for workpiece material, machining accuracy and surface finish, which requires high reliability of the machining system. Thus, it also puts forward high requirements for machine tools, fixtures, cutting tools, CAM software, etc. The workpiece is usually processed on Swiss automatic lathe, multi spindle machine tool, rotary table and other advanced medical equipment. Most of these machine tools are characterized by very small size and very compact structure.