Surface hardness changes induced by O-, Ca- or P-ion implantation into titanium

Area of Science:

• Biomaterials Science
• Surface Engineering
• Materials Science

Background:

• Titanium and its alloys are highly sought after for biomedical applications due to their favorable properties.
• Understanding surface modifications is crucial for optimizing titanium's performance in biological environments.

Purpose of the Study:

• To investigate the effects of implanting biocompatible elements (oxygen, calcium, phosphorus) into titanium.
• To quantify changes in surface hardness and correlate them with ion implantation parameters.

Main Methods:

• Surface hardness profiles were measured using an ultra-micro indenter (UMIS-2000) with a multiple load-partial unload technique.
• Ion concentration depth profiles were analyzed using secondary ion mass spectrometry (SIMS).

Main Results:

• Oxygen and phosphorus implantation dose-dependently increased titanium's surface hardness, with oxygen achieving up to a 2.2-fold increase.
• Calcium implantation resulted in a minor, dose-independent hardness increase and a significantly thicker surface oxide layer.
• The depth of maximum hardness correlated with the energy of implanted ions, occurring at depths one-third to one-eighth of the ions' mean range.

Conclusions:

• Surface hardness of titanium can be effectively enhanced through ion implantation of specific biocompatible elements like oxygen and phosphorus.
• The choice of implanted element and its energy significantly influences the resulting surface properties, including hardness and oxide layer formation.
• These findings provide valuable insights for designing advanced titanium-based biomedical implants with tailored surface characteristics.