Ceramic bonding to biocompatible titanium alloys obtained by powder metallurgy

Abstract

The shear bond strength between a ceramic material (Titankeramik® , Vita Zahnfabrik, Germany) and two biocompatible titanium alloys was investigated. Ti-13%Nb-13%Zr (TNZ) and Ti-35%Nb-7%Zr-5%Ta (TNZT) alloys were obtained based on the blended elemental technique followed by a sequence of cold uniaxial and isostatic pressing and sintering. Characterization involved microstructural analysis (SEM) and crystalline phase identification (XRD). Subsequently, samples were machined to 4 x 4 mm with a base of 5 x 1 mm. The base metals were blasted with Al2O3 particles followed by the application of a coupling agent and opaque ceramic. After ceramic firing, the specimens were loaded in a universal testing machine (0,5mm/min). XRD revealed the presence of α and β-phases for TNZ, and peaks related to β phases and Nb and Ta for the TNZT alloy. SEM evaluation (TNZ) depicted remaining pores and biphasic microstructure formation. SEM micrographs of the TNZT alloy revealed good densification and a homogeneous β structure. Shear bond strength data (MPa) were statistically analyzed (one-way ANOVA and Tukey test, α=.05) revealing that TNZT (37.6 ± 2.91) presented significant higher values (p=0.0002) compared to TNZ (26.03 ± 2.92). In conclusion, it seems that Ti alloy composition plays a significant role on ceramic bonding.