Integrated processing of Al2O3/ZrO2 eutectic implants with bioactive Ca-P coatings by laser cladding

Al(2)O3/ZrO2 composites are currently popular for orthopaedic and dental restorations. However, the long-term reliability of Al(2)O3/ZrO2 implants should be further improved by reducing the aging sensitivity and enhancing the osteointegration performance. In this paper, melt-grown Al(2)O3/ZrO2 eutectics with bioactive Ca-P coatings are successfully pre -pared by successive laser cladding technique. The processing strategy is studied to show that the laser power has a significant influence on the phase constituent, surface morphology and mechanical properties of Ca-P coatings. The aggravated elements inter -diffusion and strong metallurgical bonding between coating and substrate is found with increased laser power from 50 W to 70 W under the same laser energy density, which leads to reduced bioactivity and enhanced adhesion strength of Ca-P coating (3.5 +/- 1.1 N to 14.9 +/- 1.4 N). The bioactivity of Al(2)O3/ZrO2 eutectics is greatly improved by the coating of highest content of 55.9% Ca-P phase under the optimized parameters with laser power of 50 W and scanning rate of 50 mm/s. A thick bone-like apatite layer with Ca/P of 1.71 similar to that of bone can be observed on the coating surface after soaking tests. Thus, laser cladding is a potential and efficient strategy to modify Al(2)O3/ZrO2 eutectics with desired biological properties, which may be applied as load-bearing implants for clinical application. (C) 2022 The Author(s). Published by Elsevier B.V.

Automated summary

This paper focuses on the development of Al(2)O3/ZrO2 composites with bioactive coatings using the laser cladding technique. The study reveals that the laser power significantly affects the phase constituent, surface morphology, and mechanical properties of the coatings. Increasing the laser power results in enhanced inter-diffusion and metallurgical bonding, leading to reduced bioactivity but increased adhesion strength of the coatings. By optimizing the parameters, the bioactivity of the composites is greatly improved with a high content of 55.9% Ca-P phase.