SRS 2020: Provost's Award - Christopher Oyuela
Presentation Title: Tri Hybrid Ultra Light Composites For Bio-applications
Abstract: The current research is focused on advancing microstructure tunability by designing micro-scale powders for use in novel Tri Hybrid Ultra-Light Composites for new orthopedic implants with superior wear resistance and a modulus that matches that of bone. Previous work from our lab has shown success in dispersing titanium di-boride (TiB2) particles inside micro-scaled titanium powders to produce composite powders of Ti-TiB2. These same powders were then mixed and sintered with pure titanium powder to produce Ti-TiBw dual matrix composites (through a high temperature in situ reaction that converts TiB2 to TiBw). The idea is to produce a titanium composite where the TiBw reinforcements are not homogeneously distributed but rather occupy regions of the microstructure that are separated by pure Ti. This microstructure creates superior tailorability of the properties and allows significantly improved properties than that of conventional composite, even at the same volume fraction of TiBw. However, we have previously found that these TiBw whiskers tend to grow outside the region and go inside the supposedly pure titanium regions. Hence this project is designed to produce dual matrix composites with whiskers completely bound within the microscopic regions. This is accomplished by milling Ti-TiB2 powders followed by converting the TiB2 to TiBw through high-temperature annealing then remilling to entrap the grown whiskers back into the Ti-TiBw particles followed by mixing with titanium powder and sintering. An additional step will be to add to the Ti-TiBw/titanium powder mixtures to foaming precursor (Ti-TiH2) powders to produce tri-hybrid (partially foamed) composites.
