Engineering Commons^™

Interfacial Thermomechanical Behavior Of Hybrid Carbon Fibers, Sriraj Srihari

Doctoral Dissertations and Master's Theses

The carbon fiber/epoxy interface is of great importance in composite design due to its load transfer mechanisms from the weak epoxy to the stronger fiber. Improving the strength of the interface reduces the risk of failure at the interface and improves the load transfer to the fiber. In this study, two types of nano-species ZnO nanowires and nickel-based metal organic frameworks were grown on carbon fibers to improve the interfaces. The interfacial mechanics of the enhanced fibers are evaluated using nanoindentation studies. Composite samples with Aeropoxy matrix and vertically aligned fibers are fabricated for this purpose. A Bruker TI-980 TriboIndenter …

Fabrication Of Smooth Sac305 Thin Films Via Magnetron Sputtering And Evaluations Of Microstructure, Creep, And Electrical Resistivity, Manish Ojha

Mechanical & Aerospace Engineering Theses & Dissertations

SAC305 (96.5%Sn-3%Ag-0.5%Cu) is the leading alternative to the traditional Sn-Pb solder eutectic alloy owing to its low melting temperature, better compatibility with other components, and excellent mechanical/structural properties. In the realm of modern electronics, where devices are increasingly miniaturized, the design and characterization of thin solder joints become paramount. The orientation and size of the grains within the solder can influence its ability to withstand mechanical stresses. However, research on SAC thin films remains sparse, and these films present unique challenges and characteristics compared to their bulk counterparts, influenced by factors like interfaces, stresses, thickness, microstructure, and the nature of …

Effect Of Ion Irradiation On The Rate Dependence Of Plastic Deformation Of Extruded Zr-2.5%Nb, Konrad P. Mazurkiewicz

Electronic Thesis and Dissertation Repository

The purpose of this thesis is to examine the properties of Zr-2.5%Nb pressure tube material in the transverse direction. Through testing at room temperature, material properties such as the strain hardening, strain rate sensitivity and apparent activation volume were investigated. The effects of Zr⁺ ion-implantation occurring at 300°C, simulating irradiation-induced damage, and the strain rate of loading on these properties were also investigated.

Two methods of testing were performed: in-situ micro-pillar compressions and nanoindentation testing. Ion-implantation was observed to increase material strength and hardness. However, certain implanted micro-pillars displayed early localized failure that reduced strength. This finding warrants further …