Fatigue Behavior of Electrodeposited Nanocrystalline Nickel Films

AbstractMaterial characterization of thin film for MEMS/nano structures is a building block for the reliability assessment. One of the most significant barriers for reliable MEMS/nano structure is the long term reliability which is different from those of bulk materials. Nano-indenter has been used widely to get the elastic modulus of materials in a very simple way but other testing machines are required for tensile and endurance properties. For the long term reliability assessment of micro/nano structures, a new micro fatigue testing machine was developed to obtain the high cycles fatigue behavior of thin films. Nanocrystalline nickel thin films exhibited significant rate dependency on tensile and fatigue behavior even in room temperature due to grain size related behavior in contrast to coarse grained wrought nickels

Oxidation of Titanium and Ti/(TiB+TiC) Composite

Titanium and titanium matrix composite reinforced with 10 vol. %(TiB+TiC) (10TMC) were oxidized at 700, 800 and 900 oC for 30, 50 and 70 h, and their oxidation behavior was studied. Oxidation of Ti and 10TMC in air led to the formation of rutile-TiO2 without any other oxides. The oxide scale thickened with an increase in the oxidation time and temperature. Significant growth of the rutile oxide caused thermal stresses which generated during oxidation and voids formed at the scale/matrix interface, and the oxide scales were susceptible to cracking.

Learning Transferable Adversarial Robust Representations via Multi-view Consistency

Despite the success on few-shot learning problems, most meta-learned models only focus on achieving good performance on clean examples and thus easily break down when given adversarially perturbed samples. While some recent works have shown that a combination of adversarial learning and meta-learning could enhance the robustness of a meta-learner against adversarial attacks, they fail to achieve generalizable adversarial robustness to unseen domains and tasks, which is the ultimate goal of meta-learning. To address this challenge, we propose a novel meta-adversarial multi-view representation learning framework with dual encoders. Specifically, we introduce the discrepancy across the two differently augmented samples of the same data instance by first updating the encoder parameters with them and further imposing a novel label-free adversarial attack to maximize their discrepancy. Then, we maximize the consistency across the views to learn transferable robust representations across domains and tasks. Through experimental validation on multiple benchmarks, we demonstrate the effectiveness of our framework on few-shot learning tasks from unseen domains, achieving over 10\% robust accuracy improvements against previous adversarial meta-learning baselines.Comment: *Equal contribution (Author ordering determined by coin flip). NeurIPS SafetyML workshop 2022, Under revie

Вплив параметрів модифікувального кисневмісного середовища на оксинітрування титанових сплавів

Досліджено вплив параметрів модифікувального кисневмісного середовища (ступеня розрідження, температури та тривалості модифікування) на оксинітрування титанових сплавів. Показано, що зі збільшенням розрідження середовища та зниженням температури модифікування фазоутворення на поверхні титанових сплавів еволюціонує у бік оксинітридоутворення, в той час як тривалість модифікування не змінює структурно-фазового стану. Зі зменшенням вмісту кисню склад оксинітриду титану наближається до еквіатомного. Це забезпечує зростання поверхневої мікротвердості та поліпшення корозійної тривкості титанових сплавів у безкисневих кислотах.Исследовано влияние параметров модифицирующей кислородсодержащей среды (степени разрежения, температуры и длительности модифицирования) на оксинитрирование титановых сплавов. Показано, что с увеличением разрежения кислородсодержащей среды и понижением температуры модифицирования фазообразование на поверхности титановых сплавов смещается в сторону оксинитридообразования, в то время как длительность модифицирования не изменяет структурно-фазового состояния. С уменьшением содержания кислорода состав оксинитрида титана приближается к эквиатомному, что повышает поверхностную микротвердость и улучшает коррозионную стойкость титановых сплавов в бескислородных кислотах.The influence of parameters of modifying oxygen-containing medium (degree of rarefaction, temperature and duration of modification) on the titanium alloys oxynitriding has been investigated. It has been shown that with increasing rarefaction of oxygen-containing medium and decreasing temperature of modification the phase formation on the surface of titanium alloys is shifted towards the oxynitride formation, while the duration of modification does not change the phase-structural state. The decrease of oxygen content approaches the titanium oxynitride composition to equiatomic one. It provides the increase of surface microhardness and improvement of corrosive resistance of titanium alloys in the oxygen-free acids