A. Antalfy, G. Jiang, Alfred Mann Foundation, Valencia, CA
Zirconia ceramics and noble metals have been used for biomedical applications due to their excellent mechanical properties, high corrosion resistance and favorable biocompatibility. Some applications, such as electrical sensors or stimulators that are implanted in a human body, require these two materials to be joined, as a composite, to combine their individual properties. A novel bonding method of Yttria Stabilized Zirconia Tetragonal Polycrystals (Y-TZP) to 90 wt. % Platinum / 10 wt. % Iridium alloy is presented. Test specimens were produced by brazing Zirconia ceramic to Platinum alloy in vacuum using clad Titanium / Nickel filler metal. Four types of braze performs were used with different Titanium / Nickel weight percent compositions. After brazing, the joint strength was determined by means of shear testing. Scanning Electron Microscopy observation, Energy Dispersive Microanalysis and X-Ray Diffraction was carried out on fracture surfaces and cross sections to study the microstructure evolution of the Zirconia to Platinum braze. The biocompatibility of the joint is discussed and an optimal Titanium / Nickel filler metal composition is suggested.
Summary: Zirconia ceramics and noble metals have been used for biomedical applications due to their excellent mechanical properties, high corrosion resistance and favorable biocompatibility. Some applications, such as electrical sensors or stimulators that are implanted in a human body, require these two materials to be joined, as a composite, to combine their individual properties. The present work will discuss a novel bonding method of Yttria Stabilized Zirconia Tetragonal Polycrystals (Y-TZP) to 90 wt. % Platinum / 10 wt. % Iridium alloy. Microstructure evolution and braze joint biocompatibility will be discussed.
