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Corrosion properties of powder bed fusion additively manufactured stainless steels

Materials Science and Technology Conference and Exhibition 2017, MS and T 2017

Schaller, Rebecca S.; Taylor, Jason M.; Rodelas, Jeffrey R.; Mishra, Ajit; Schindelholz, Eric J.

Metal additive manufacturing (AM) has recently become a desirable process for complex parts across a broad range of applications. However, AM materials often have a varied microstructure due to non-equilibrium solidification conditions. While some adjustments have been made in manufacturing to enhance mechanical traits, very little attention has been directed at understanding the corrosion properties of these materials. The microstructural characteristics of the AM materials may lead to reduction in the corrosion resistance of the AM alloys compared to their conventional counterparts. This presentation explores the corrosion susceptibility of AM stainless steels in aqueous sodium chloride environments as well as industry relevant solutions. Further detailed corrosion studies combined with microstructural characterization provide insight into the microstructural influences on corrosion.

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The influence of salt loading density on the atmospheric corrosion of aluminum

NACE - International Corrosion Conference Series

Schaller, Rebecca S.; Schindelholz, Eric J.; Taylor, Jason M.

Corrosion of aluminum and aluminum alloys under atmospheric exposure has been well documented for outdoor conditions. While these studies expose the effects of environmental severity they do not explicitly establish the dependence of corrosion rate on salt loading. Accelerated laboratory studies have shown that initial corrosion rates are generally higher with higher salt loadings, but, over time corrosion appears to effectively stifle for low loadings of NaCl (<100 μg/cm2) under fixed humidity conditions. This has previously been attributed to the stability or passivation of the surface that is pH and, in turn, CO2 dependent. Another possible explanation could be the gettering of NaCl by corrosion product leading to surface drying and depletion of the corrosion aggressor. This paper explores the effects of selected NaCl loading densities vs. exposure time of UNS A91100 at both the macro and micro scale to illuminate the possible mechanisms leading to corrosion stifling. Through this work, an understanding of the relationship between corrosion in atmospheric systems versus the variation of a specific environmental severity factor, NaCl loading density, will be further developed.

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Characterization of fire hazards of aged photovoltaic balance-of-systems connectors

2015 IEEE 42nd Photovoltaic Specialist Conference, PVSC 2015

Schindelholz, Eric J.; Yang, Benjamin B.; Armijo, Kenneth M.; McKenzie, Bonnie B.; Taylor, Jason M.; Sorensen, Neil R.; Lavrova, Olga A.

Three balance of systems (BOS) connector designs common to industry were investigated as a means of assessing reliability from the perspective of arc fault risk. These connectors were aged in field and laboratory environments and performance data captured for future development of a reliability model. Comparison of connector resistance measured during damp heat, mixed flowing gas and field exposure in a light industrial environment indicated disparities in performance across the three designs. Performance was, in part, linked to materials of construction. A procedure was developed to evaluate new and aged connectors for arc fault risk and tested for one of the designs. Those connectors exposed to mixed flowing gas corrosion exhibited considerable Joule heating that may enhance arcing behavior, suggesting temperature monitoring as a potential method for arc fault prognostics. These findings, together with further characterization of connector aging, can provide operators of photovoltaic installations the information necessary to develop a data-driven approach to BOS connector maintenance as well as opportunities for arc fault prognostics.

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Arc fault risk assessment and degradation model development for photovoltaic connectors

2014 IEEE 40th Photovoltaic Specialist Conference, PVSC 2014

Yang, Benjamin B.; Armijo, Kenneth M.; Harrison, Richard K.; Thomas, Kara E.; Johnson, Jay; Taylor, Jason M.; Sorensen, Neil R.

This work investigates balance of systems (BOS) connector reliability from the perspective of arc fault risk. Accelerated tests were performed on connectors for future development of a reliability model. Thousands of hours of damp heat and atmospheric corrosion tests found BOS connectors to be resilient to corrosion-related degradation. A procedure was also developed to evaluate new and aged connectors for arc fault risk. The measurements show that arc fault risk is dependent on a combination of materials composition as well as design geometry. Thermal measurements as well as optical emission spectroscopy were also performed to further characterize the arc plasma. Together, the degradation model, arc fault risk assessment technique, and characterization methods can provide operators of photovoltaic installations information necessary to develop a data-driven plan for BOS connector maintenance as well as identify opportunities for arc fault prognostics.

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Results 26–42 of 42
Results 26–42 of 42