@article{o'brien_christudasjustus_delvecchio_birbilis_gupta_2023, title={Microstructure and corrosion of CrFeMnV multi-principal element alloy}, volume={222}, ISSN={["1879-0496"]}, DOI={10.1016/j.corsci.2023.111403}, abstractNote={A multi-principal element alloy consisting of equiatomic concentrations of Cr, Fe, Mn, and V was produced by arc melting. The combination of X-ray diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy indicated that the CrFeMnV MPEA was comprised of a BCC matrix with a dispersion of a secondary phase. Cyclic potentiodynamic polarization tests in 0.6 M NaCl revealed high corrosion resistance – superior to that of stainless steel 304L, as evident from high breakdown and repassivation potentials. X-ray photoelectron spectroscopy and time-of-flight secondary ion mass spectrometry provided insight into the formed multi-layer surface film after constant immersion and potentiostatic conditioning.}, journal={CORROSION SCIENCE}, author={O'Brien, S. P. and Christudasjustus, J. and Delvecchio, E. and Birbilis, N. and Gupta, R. K.}, year={2023}, month={Sep} }
 @article{li_nash_o'brien_qiu_gupta_birbilis_2022, title={cardiGAN: A generative adversarial network model for design and discovery of multi principal element alloys}, volume={125}, ISSN={["1005-0302"]}, url={https://doi.org/10.1016/j.jmst.2022.03.008}, DOI={10.1016/j.jmst.2022.03.008}, abstractNote={• A generative model was developed for predicting and designing MPEAs. • The model presented herein, termed cardiGAN, was demonstrated as capable of functioning with high accuracy in performance. • The cardiGAN model may be utilized to generate large numbers of candidate MPEAs with minimal computational burden, generating novel compositions. Multi-principal element alloys (MPEAs), inclusive of high entropy alloys (HEAs), continue to attract significant research attention owing to their potentially desirable properties. Although MPEAs remain under extensive research, traditional (i.e. empirical) alloy production and testing are both costly and time-consuming, partly due to the inefficiency of the early discovery process which involves experiments on a large number of alloy compositions. It is intuitive to apply machine learning in the discovery of this novel class of materials, of which only a small number of potential alloys have been probed to date. In this work, a proof-of-concept is proposed, combining generative adversarial networks (GANs) with discriminative neural networks (NNs), to accelerate the exploration of novel MPEAs. By applying the GAN model herein, it was possible to directly generate novel compositions for MPEAs, and to predict their phases. To verify the predictability of the model, alloys designed by the model are presented and a candidate produced – as validation. This suggests that the model herein offers an approach that can significantly enhance the capacity and efficiency of development of novel MPEAs.}, journal={JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY}, author={Li, Z. and Nash, W. T. and O'Brien, S. P. and Qiu, Y. and Gupta, R. K. and Birbilis, N.}, year={2022}, month={Oct}, pages={81–96} }
 @article{esteves_witharamage_christudasjustus_walunj_o'brien_ryu_borkar_akans_gupta_2021, title={Corrosion behavior of AA5083 produced by high-energy ball milling}, volume={857}, ISSN={["1873-4669"]}, url={http://dx.doi.org/10.1016/j.jallcom.2020.158268}, DOI={10.1016/j.jallcom.2020.158268}, abstractNote={The corrosion, microstructure, and hardness of nanocrystalline AA5083 were compared to that of conventional AA5083-H116 and consolidated gas atomized powder. The nanocrystalline AA5083 was produced by consolidating high-energy ball milled gas atomized powder with two methods: cold compaction and spark plasma sintering. Electrochemical impedance spectroscopy, cyclic potentiodynamic polarization, Mott-Schottky analysis, and immersion tests followed by surface analysis were used to evaluate the corrosion behavior in 0.6 M NaCl solution. Pitting corrosion resistance of the nanocrystalline AA5083 was superior to that of commercial AA5083-H116. The improved corrosion resistance was primarily attributed to the homogenous microstructure and significant grain refinement below 100 nm.}, journal={JOURNAL OF ALLOYS AND COMPOUNDS}, publisher={Elsevier BV}, author={Esteves, L. and Witharamage, C. S. and Christudasjustus, J. and Walunj, G. and O'Brien, S. P. and Ryu, S. and Borkar, T. and Akans, R. E. and Gupta, R. K.}, year={2021}, month={Mar} }
 @article{esteves_christudasjustus_o'brien_witharamage_darwish_walunj_stack_borkar_akans_gupta_2021, title={Effect of V content on corrosion behavior of high-energy ball milled AA5083}, volume={186}, ISSN={["1879-0496"]}, url={https://doi.org/10.1016/j.corsci.2021.109465}, DOI={10.1016/j.corsci.2021.109465}, abstractNote={AA5083 alloys with V additions were produced in the powder form by high-energy ball milling and consolidation by spark plasma sintering and cold compaction. X-ray diffraction and energy dispersive X-ray spectroscopy analysis indicated the formation of supersaturated solid solution and grain refinement below 100 nm. Corrosion behavior was investigated using electrochemical impedance spectroscopy, cyclic potentiodynamic polarization, and immersion corrosion tests followed by surface analysis. The composition of the passive film was obtained via X-ray photoelectron spectroscopy. The corrosion resistance of the AA5083 was significantly improved due to the addition of V and high-energy ball milling.}, journal={CORROSION SCIENCE}, publisher={Elsevier BV}, author={Esteves, L. and Christudasjustus, J. and O'Brien, S. P. and Witharamage, C. S. and Darwish, A. A. and Walunj, G. and Stack, P. and Borkar, T. and Akans, R. E. and Gupta, R. K.}, year={2021}, month={Jul} }
 @article{choudhary_s. o'brien_qiu_thomas_gupta_birbilis_2021, title={On the dynamic passivity and corrosion resistance of a low cost and low density multi-principal-element alloy produced via commodity metals}, volume={125}, ISBN={1873-1902}, DOI={10.1016/j.elecom.2021.106989}, abstractNote={Recent exploration of multi-principal-element alloys (MPEAs), which include the so-called high-entropy alloys, has revealed hitherto unreported properties and phenomena arising from investigation of broader compositional space. Herein, a low cost and lightweight alloy (equiatomic AlFeMnSi) is presented that exhibits exceptional corrosion resistance in 0.6 M NaCl solution, despite a multiphase structure and the absence of well-known passivating elements (such as Cr, Mo, Ti and Nb). In-line inductively-coupled plasma mass spectroscopy (ICP-MS) analysis of alloy dissolution and angle-resolved X-ray photoelectron spectroscopy (AR-XPS) of the surface film revealed that the alloy passivates by a unique mechanism involving dissolution–precipitation of Si. The dynamic precipitation of a Si hydroxide surface film results in excellent passivity of the alloy, revealing the possibility of developing low-cost corrosion-resistant alloys from metals available from waste streams.}, journal={ELECTROCHEMISTRY COMMUNICATIONS}, author={Choudhary, S. and S. O'Brien and Qiu, Y. and Thomas, S. and Gupta, R. K. and Birbilis, N.}, year={2021}, month={Apr} }