Advanced surface modification of CoCr alloys for biomedical Applications: The impact of TiB2 and BN coatings on wear, hardness, and radiation shielding

Abstract

This research looks into how Boron Nitride (BN) and Titanium Diboride (TiB2) coatings change the surface properties of biomedical CoCr alloys made with selective laser melting (SLM) technology. SEM analyses confirmed uniform coating thicknesses compatible with theoretical calculations. Radiation attenuation tests demonstrated increased linear attenuation coefficients (LAC) and mass attenuation coefficients (MAC) at 1.173 MeV for both coatings, with TiB2 providing superior performance. Mechanical tests revealed significant improvements in hardness, with TiB2 and BN increasing it by 16.2 % and 15.9 %, respectively. Wear tests showed that BN coatings reduced friction coefficients, while TiB2 increased wear resistance. HVL, TVL, and MFP parameters showed improved gamma shielding at 1.173 MeV, though less effectiveness at 1.332 MeV. These results indicate that BN and TiB2 coatings enhance the mechanical, wear, and radiation attenuation properties of CoCr alloys, making them suitable for long-lasting biomedical implants