Evaluation of Biomedical Ti/ZrO2 Joint Brazed with Pure Au Filler: Microstructure and Mechanical Properties
Yuzhen Lei, Hong Bian, Wei Fu, Xiaoguo Song, Jicai Feng, Weimin Long, Hongwei Niu
Abstract
Titanium and zirconia (ZrO2) ceramics are widely used in biomedical fields. This study aims to achieve reliable brazed joints of titanium/ZrO2 using biocompatible Au filler for implantable medical products. The effects of brazing temperature and holding time on the interfacial microstructures and mechanical properties of titanium/Au/ZrO2 joints were fully investigated by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results indicated that the typical interfacial microstructure of the titanium/Au/ZrO2 joint was titanium/Ti3Au layer/TiAu layer/TiAu2 layer/TiAu4 layer/TiO layer/ZrO2 ceramic. With an increasing brazing temperature or holding time, the thickness of the Ti3Au + TiAu + TiAu2 layer increased gradually. The growth of the TiO layer was observed, which promoted metallurgical bonding between the filler metal and ZrO2 ceramic. The optimal shear strength of ~35.0 MPa was obtained at 1150 °C for 10 min. SEM characterization revealed that cracks initiated and propagated along the interface of TiAu2 and TiAu4 reaction layers.