Hip replacement surgery or total hip arthroplasty, involves removing a diseased hip joint and replacing it with an artificial joint, called a prosthesis /
Hip implants consist of:
- a socket (acetabular cup/shell), which has an insert or liner made of plastic, ceramic or metal
- a ball component (femoral head), made of metal or ceramic
- a metal stem (femoral stem) are made of titanium- or cobalt/chromium-based alloys (In some designs, the stem and ball are one piece; other designs are modular, allowing for additional customization)
Hip implants are usually made of cobalt chrome (e.g. ASTM F1537), titanium (e.g. Ti6Al4V ELI) or medical Grade Stainless Steel (316LVM).
The machines that are typically used for the component include Multi Axis Machines, 3 axis lathes, 5 axis VMC and Multi Task machines (e.g. Mazak Intergrex E410e).
- Fixturing is a challenge
- Small batch production
- Some forged and cast blanks for the stem
- Bar work for the Femoral Head and Cup
Circular ramping machining of the internal sphere is a highly effective and secure process with the benefits of longer tool life, less tool breakage and short cycle time resulting in a high quality surfaces. Preferably use positive round inserts
Benefits when machining the external sphere include increased tool life and a secure process.
External head machining gives high quality surfaces and increased tool life in a secure process. Preferably use positive round inserts.
Head taper hole machining is an effective process for flat bottom.