Out-of-plane magnetic patterning on austenitic stainless steels using plasma nitriding

This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics.A correlation between the grain orientation and the out-of-plane magnetic properties of nitrogen-enriched polycrystalline austenitic stainless steel surface is performed. Due to the competition between the magnetocrystalline anisotropy, the exchange and dipolar interactions, and the residual stresses induced by nitriding, the resulting effective magnetic easy-axis can lay along unusual directions. It is also demonstrated that, by choosing an appropriate stainless steel texturing, arrays of ferromagnetic structures with out-of-plane magnetization, embedded in a paramagnetic matrix, can be produced by local plasma nitriding through shadow masks

A combinatorial study of the mechanical and magnetic properties of a gradually nitrided austenitic stainless steel single crystal

The mechanical and magnetic properties of a nitrided austenitic stainless steel are studied using a combinatorial approach. Plasma nitriding of a [100]-oriented 316L single crystal is carried out using a loose shadow mask to produce an in-plane lateral gradient of nitrogen concentration that extends up to 100 μm. The local mechanical and magnetic properties across the gradually nitrided area are resolved by nanoindentation and the polar magneto-optic Kerr effect, respectively. The hardness, reduced Young's modulus and remanence qualitatively depict the nitrogen profile, suggesting that the nitrogen concentration is a central effect for these observed dependencies. Conversely, the coercivity exhibits a non-monotonic behaviour due to the interplay between magnetic anisotropy and the strength of the induced ferromagnetism. Fingerprints of the expected transition from a nitrogen supersaturated solid solution to a multiphase nature of expanded austenite are evidenced along the gradually nitrided area. © 2014 the Partner Organisations

Mechanical failure analysis of thin film transistor devices on steel and polyimide substrates for flexible display applications

The crack onset strain (COS) of 4-level thin film transistor (TFT) devices on both steel foils and thin polyimide (PI) films was investigated using tensile experiments carried out in situ in an optical microscope. Cracks initiated first within the SiO2 insulator layer for both types of substrates. The COS was found to be equal to 1.15% and 0.24% for steel and PI, respectively. The influence of loading direction on failure of the TFT stack with anisotropic geometry was moreover found to be considerable, leading to recommendations for backplane design. The large difference in critical strain of the SiO2 layer on the two substrates was analyzed using an energy release rate approach, and found to result from differences in layer/substrate mechanical contrast and in internal stress state. Based on this analysis a correlation between layer/substrate elastic contrast and tensile failure behavior was devised. (C) 2010 Elsevier Ltd. All rights reserved

Knowledge Boundary Spanning Mechanisms in a Shared Services Centre Context

This study focuses on the roles of knowledge boundary spanning mechanisms and intellectual capital (human, structural, and relational) in managing knowledge sharing in an IT-specialized shared services centre (IT-SSC) context. Although the literature stresses the growing utilization of the SSC as an outsourcing model, there is a lack of studies that examine the dynamic process of knowledge sharing across the organizational boundaries in this specific business model. Drawing on the literatures on SSC and on cross-boundary knowledge sharing we propose a conceptual framework based on four research propositions that were validated with primary and secondary data. The results suggest that IT-SSCs present high human capital, but encounter challenges developing relational and structural capitals. It also appears that IT-SSC management tends to prefer the utilization of boundary spanners and boundary objects instead of boundary discourses and boundary practices as mechanisms for efficient boundary spanning

On the nitrogen-induced lattice expansion of a non-stainless austenitic steel, Invar 36®, under triode plasma nitriding

Chromium, as a strong nitride-forming element, is widely regarded to be an “essential” ingredient for the formation of a nitrogen-expanded lattice in thermochemical nitrogen diffusion treatments of austenitic (stainless) steels. In this article, a proprietary “chrome-free” austenitic iron-nickel alloy, Invar® 36 (Fe-36Ni, in wt pct), is characterized after triode plasma nitriding (TPN) treatments at 400 °C to 450 °C and compared with a “stainless” austenitic counterpart RA 330® (Fe-19Cr-35Ni, in wt pct) treated under equivalent nitriding conditions. Cr does indeed appear to play a pivotal role in colossal nitrogen supersaturation (and hence anisotropic lattice expansion and superior surface hardening) of austenitic steel under low-temperature (≤ 450 °C) nitrogen diffusion. Nevertheless, this work reveals that nitrogen-induced lattice expansion occurs below the nitride-containing surface layer in Invar 36 alloy after TPN treatment, implying that Cr is not a necessity for the nitrogen-interstitial induced lattice expansion phenomenon to occur, also suggesting another type of γN

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