Facile fabrication of boronized Ti6Al4V/HA composites for load-bearing applications

Fabrication of Boronized Ti6Al4V/HA Composites by Microwave Sintering in Mixed Gases

“…The boronized Ti6Al4V/HA composite obtained in the atmosphere consisting of both Ar and H 2 exhibited the optimal mechanical properties and wettability, meeting the corresponding requirements of most load-bearing implantation applications, such as dental implantation, which is one of the main methods for repairing the missing teeth. 31 In fact, it possessed higher compressive strength and modulus than those of the similar product reported in the literature (148.59 vs 93 MPa, 13.9 GPa vs 2.9 MPa, respectively). 5 It may also have very attractive biological properties, which have been partially verified by the desirable biological activities of relevant Ti6Al4V-based composites with similar compositions.…”

“…Volumetric heating might also occur during the process as the alloy matrix particles had sizes that matched with the corresponding micrometer-scale skin depth of microwave, enabling heating of all matrix particles. The combined microwave selective and volumetric thermal effects could result in a more efficient fabrication of the composite under microwave irradiation than the conventional approach, as verified by the significant reductions of sintering temperature and time (approximately 200 °C and over 1.5 h) in relevant previous studies. , …”

“…The combined microwave selective and volumetric thermal effects could result in a more efficient fabrication of the composite under microwave irradiation than the conventional approach, as verified by the significant reductions of sintering temperature and time (approximately 200 °C and over 1.5 h) in relevant previous studies. 31,36 Figure 5 shows the bulk densities of the composites obtained by microwave sintering in different atmospheres. The composite obtained in the mixed gas of Ar + CO had the lowest bulk density.…”

“…It should be pointed out that for typical load-bearing implant applications, the compressive strength is usually at least 77 MPa. 31 From this perspective, only the composite fabricated in the mixed gas of Ar + H 2 met the standard.…”

“…It explained the noticeable observation of TiN and TiC in the corresponding XRD patterns (Figure ) and SEM micrographs (Figure ). Meanwhile, the generations of these compounds restrained the production of TiB layer, which was intensified by the “lens effect” of the microwave electric field . For this reason, the loose microstructures of the composites were more apparent when sintered in mixed gases of Ar + N 2 and Ar + CO. On the other hand, the phase components were intertwined and distributed relatively evenly in the composite synthesized in the mixed gas of Ar + H 2 , in spite of the existence of incompletely eliminated interfaces and a few entrapped micropores due to the gas emission from the partial decomposition of HA to β-TCP (eq ) and to the different coefficients of thermal expansion of the alloy matrix and HA (8.2 × 10 –6 /°C for Ti vs 16 × 10 –6 /°C for HA). , Note that as a result of the selective thermal effect, the microwave could contribute to the low decomposition of HA because of its poor microwave absorptivity .…”