Date of Award
Winter 3-6-2026
Document Type
Thesis (Master's)
Department or Program
Engineering Sciences
First Advisor
Ian Baker
Second Advisor
Doug van Citters
Third Advisor
William Scheideler
Abstract
The performance of metallic materials is governed by the interplay between composition, microstructure, and service environment. This thesis investigates two complementary aspects of materials behavior relevant to biomedical and structural applications: corrosion resistance in complex alloys and deformation-induced microstructural transformation in stainless steel. First, the corrosion behavior of two high-entropy alloys (HEAs), also referred to as complex concentrated alloys (CCAs)—Fe₄₀.₄Ni₁₁.₃Mn₃₄.₈Al₇.₅Cr₆ with 1.1 at% carbon (CHEA) and Fe₄₂Mn₂₈Co₁₀Cr₁₅Si₅ (DP-5Si-HEA)—was evaluated using potentiodynamic polarization techniques. Testing was conducted at room temperature and 40 °C in simulated physiological environments, including Ringer’s solution with lactate as well as monoprotic (1 M glacial acetic acid) and diprotic (1 M sulfuric acid) acidic conditions. Post-corrosion surface morphology was examined using scanning electron microscopy. Results indicate that DP-5Si-HEA consistently exhibited lower corrosion rates than CHEA across all environments. In sulfuric acid at 40°C, CHEA reached a corrosion rate of 5.60 mm·year⁻¹, while DP-5Si-HEA measured 3.39 mm·year⁻¹. In acetic acid at the same temperature, corrosion rates were 1.14 mm·year⁻¹ for CHEA and 6.04 × 10⁻² mm·year⁻¹ for DP-5Si-HEA. Both alloys demonstrated effective passivation in neutral Ringer’s + lactate solution, with corrosion rates decreasing by several orders of magnitude.
The second part of this work examines the role of temperature on deformation-induced austenite-to-martensite transformation in SS316L stainless steel under uniaxial tension. Tensile specimens were strained to fracture at −15, 0, 10, and 20°C using a temperature-controlled experimental setup incorporating a cooling system and heat exchanger. Digital image correlation and thermal imaging were employed to capture strain and temperature evolution at 0°C and above. Together, these studies highlight how compositional complexity and thermomechanical conditions govern microstructural evolution and performance, supporting a materials-by-design approach for advanced alloy development.
Recommended Citation
Kuijer, Michael Bram, "A Potentiodynamic Study of the Corrosion of Two Novel High Entropy Alloys And Martensitic Transformation of 316L Stainless Steel Due to Temperature and Strain" (2026). Dartmouth College Master’s Theses. 275.
https://digitalcommons.dartmouth.edu/masters_theses/275
