- When processing titanium for use in surgical implants, the most essential characteristic is biocompatibility.
- This means the material must be able to coexist within the human body without causing any adverse reactions such as inflammation, toxicity, or rejection. Titanium is widely used in medical implants because it has excellent biocompatibility, allowing it to integrate well with bone and soft tissues.

- While corrosion resistance is also important, as it prevents the implant from degrading inside the body, it is considered part of the broader aspect of biocompatibility.
- The body’s environment is highly corrosive due to bodily fluids, so implants must resist corrosion to maintain their integrity over time.

- Thermal conductivity and high electrical conductivity are not primary concerns for surgical implants.
- In fact, high electrical conductivity is generally not required and may be undesirable, as implants should not interfere with the body's natural electrical signals.

To summarize:
- Biocompatibility ensures the implant is safe and effective within the body.
- Corrosion resistance supports biocompatibility by maintaining implant stability.
- Thermal and electrical conductivity are not critical for implant performance.

Therefore, the crucial characteristic when processing titanium for surgical implants is biocompatibility.

Reference: Biomaterials Science, Volume 1, Chapter 5, Page 145