Ph.D. Research: Certain spring applications require a material with a combination of high strength, stiffness, and electrical conductivity. An alloy consisting of Cu-15Ni-8Sn (C72900) is one of several copper based alloys which can be heat treated/processed to form a metallic nano-structured alloy with good combinations of yield strength and
electrical conductivity. For certain heat treatment conditions, this alloy
decomposes spinodally from a face centered cubic disordered phase to form tin-rich and tin-lean composition fluctuations that are only 10-100nm thick.
Additional time at temperature produces ordering of the tin-rich regions.
Uniaxial tensile tests have been used to identify aging conditions having high yield strength. Tensile and flexural fatigue properties of the various heat-treated conditions will be compared with observed fracture surfaces and microstructures in an effort to identify the failure mechanisms of the various time and temperature evolved microstructures. Optical metallography, transmission electron microscopy, differential scanning calorimetry traces and X-Ray diffraction spectra are included in order to map the evolution of specific micro- and nano-structural features with various heat treatments.
Conference Posters:
Journal Papers:
Post-doctoral studies: The effects of changes in test temperature, thermal exposure, and strain rate on the mechanical behavior of both Ca-based and Mg-based metallic glasses are being determined. Toughening approaches based on both intrinsic (e.g. Chemistry, deformation characteristics) and extrinsic (e.g. Composite approaches, lamination, etc.) are being explored.
Conference Posters:
- Temperature and Loading Rate effects on the Mechanical Behavior of Ca based BMG
