Search results for "alloying"
showing 8 items of 8 documents
Evaluating the material resource efficiency of secondary aluminium production: A Monte Carlo-based decision-support tool
2019
The contamination of aluminium streams during the different life cycle stages by alloy mixing and/or accumulation of foreign elements, in combination with the limited melt purification options during remelting, represents an important limiting factor in recycling. Consequently, in secondary aluminium production, primary aluminium is used to dilute the concentration of the residual elements, and alloying elements are added to adjust the composition to the target alloy specifications. However, adding elements, for which their refinement in a subsequent recycling step is problematic, results in permanent down-cycling or ‘quality losses’. Hence, it is crucial to more efficiently control the com…
Effects of ball-milling on the hydrogen sorption properties of LaNi5
2009
Abstract Pressure–composition isotherms of LaNi 5 alloys were studied as function of ball-milling time. Results indicate that ball-milling convert a part of the LaNi 5 to a non-absorbing state—a state which does not absorb hydrogen under conditions where un-milled LaNi 5 powders absorb and transform to LaNi 5 H 6 , in addition to particle size reduction and creation of defects. The non-absorbing fraction in the milled sample is found to grow with increase in the ball-milling time. The resistance to the hydride formation of the long-time ball-milled LaNi 5 samples is found to continue even after a 1-h high vacuum annealing at around 1000 K. This indicates that the hydrogen-absorption-resist-…
Investigation of precipitate in an austenitic ODS steel containing a carbon-rich process control agent
2018
This work has been carried out within the framework of the German Helmholtz Association and has received funding from the topic “Materials Research for the Future Energy Supply”. The work of M. Parish and Rainer Ziegler is gratefully acknowledged. Thanks are also due to the team of the chemical laboratory at the KIT for performing the chemical analysis. The help of the beamline staff at ELETTRA (project 20140052 ) synchrotron radiation facility is acknowledged. We acknowledge support by Deutsche Forschungsgemeinschaft and Open Access Publishing Fund of Karlsruhe Institute of Technology.
Comparison of the effect of non-polluted and underwater-volcano-polluted seawater on the corrosion resistance of different stainless steels
2015
This work compares the effect of non‐polluted and underwater‐volcano‐polluted seawater on the electrochemical behavior of two different alloys, notably an austenitic stainless steel (SS) and a duplex stainless steel. Polarization measurements, potentiostatic passivation tests, electrochemical impedance spectroscopy and capacitance measurements were performed. Results show that the composition of the polluted seawater negatively affects the passivation kinetics of both AISI 316 SS and Alloy 900, decreasing the corrosion resistance of both alloys. Additionally, when both steels are compared, it can be concluded that passive films formed on Alloy 900 presented better protective properties than…
Partial cation-substitution in the sulphide kesterite: Absorber and heterojunction engineering
2019
International audience; The kesterite-based solar cells still suffer from a low conversion efficiency due to the large defect of the open circuit voltage Voc. This defect is mainly due to several problems related to the absorber material and the device interfaces. It has been reported that the partial cation substitution in the kesterite structure, can improve many properties of the absorbent layer and the device, i.e. improve the grain size, minimise the anti-site defects and disorder in the Cu-Zn plane, ameliorate the charge separation at the buffer/absorber interface. In this work, thin films of suphide kesterite are made by substituting copper (Cu) with silver (Ag) and zinc with mangane…
Structural and hydrogenation study on the ball milled TiH2–Mg–Ni
2015
International audience; With the aim of further understanding for TieNieMg alloys and their hydrogenation behavior, powders of TiH2, Mg and Ni with the molar ratio of 3:1:2 have been mechanically milled for 10 h, 20 h, 30 h, 40 h according to the stoichiometry (TiH2)1.5Mg0.5Ni. Microstructures of the milled sample were analyzed and their hydrogenation properties as negative electrodes for Ni-MH batteries were studied. Phase change with milling time revealed the fast formation of the Ti-Mg-H FCC phase. The alloying priority among Ti, Mg and Ni was demonstrated by comparing phase compositions in different milling time. Hydrogen capacities evaluated by both solidegas reaction and electrochemic…
ODS tērauda izejmateriālu lokālās struktūras analīze izmantojot Ti un Y K-malas rentgenabsorbcijas spektroskopiju
2017
Šajā darbā tika izmantota rentgenstaru absorbcijas spektru analīze oksīdu stiprinātam tēraudam (ODS), kas ir perspektīvs materiāls dažādās jomās, piemēram, saules elektrostacijās, reaktīvos dzinējos, ķīmiskos reaktoros un kodolreaktoros, jo materiālam piemīt tādas īpašības kā laba siltumvadītspēja un zema termiskās izplešanās apvienojumā ar augstu temperatūras izturību, korozijas un radiācijas pretestību. Darbā tiek iegūta informācija par ar dažādām metodēm izgatavotu ODS tēraudu lokālās atomārās struktūras izmaiņu ap itrija (Y) un titāna (Ti) atomiem, analizējot Y un Ti absorbcijas K-malu.
Ti Alloyed α-Ga2O3: Route towards Wide Band Gap Engineering
2020
The suitability of Ti as a band gap modifier for &alpha