Concept

Colored gold

Related publications (29)

A customized MOF-polymer composite for rapid gold extraction from water matrices

Wendy Lee Queen, Daniel Teav Sun, Shuliang Yang, Jun Li, Li Peng, Olga Syzgantseva

With the fast-growing accumulation of electronic waste and rising demand for rare metals, it is compelling to develop technologies that can promotionally recover targeted metals, like gold, from waste, a process referred to as urban mining. Thus, there is ...

AMER ASSOC ADVANCEMENT SCIENCE2023

Control of intermetallics in the interface in directed energy deposition of titanium on stainless steel 316L

Di Cui

Application of a single metal or alloy is often restricted by its properties from optimal combination of performance and cost. Therefore, there is a vast need of joining dissimilar metals for various applications in biomedical, aerospace, automobile and ma ...

EPFL2023

Modeling high-entropy transition metal alloys with alchemical compression

Michele Ceriotti, Sandip De, Guillaume André Jean Fraux, Nataliya Lopanitsyna

Alloys composed of several elements in roughly equimolar composition, often referred to as high-entropy alloys, have long been of interest for their thermodynamics and peculiar mechanical properties, and more recently for their potential application in cat ...

AMER PHYSICAL SOC2023

Persistence of variant selection in red gold alloys

Roland Logé, Cyril Cayron, Margaux Nathalie Dominique Larcher

Recently, a new thermally activated distortion with amplification (TADA) effect has been reported in red gold alloys caused by the A1 -> L1(0) phase transformation. The macroscopic amplification is due to the persistence of variant selection nucleated unde ...

ELSEVIER SCIENCE SA2022

Ultimate Limit for Optical Losses in Gold, Revealed by Quantitative Near-Field Microscopy

Sergejs Boroviks

We report thorough measurements of surface plasmon polaritons (SPPs) running along nearly perfect air-gold interfaces formed by atomically flat surfaces of chemically synthesized gold monocrystals. By means of amplitude-and phase-resolved near-field micros ...

AMER CHEMICAL SOC2022

Understanding Thermomechanical Treatments Induced by Laser Powder Bed Fusion Process

Hossein Ghasemi Tabasi

Additive Manufacturing (AM) is referred to technologies that produce directly 3D parts in a layer-by-layer fashion. Laser Powder Bed Fusion (L-PBF) is one of the most important AM processes, enabling production of very complex metallic objects from a compu ...

EPFL2021

Phase transformation induced distortions in red gold alloys

Margaux Nathalie Dominique Larcher

Red gold alloys owe their warm and attractive colour to the combination of gold and copper atoms. Thanks to their good mechanical properties and resistance to corrosion, red gold alloys are used in luxury industries as well as in dentistry. Around the equi ...

EPFL2021

Super adsorption performance of carboxymethyl cellulose/copper oxide-nickel oxide nanocomposite toward the removal of organic and inorganic pollutants

Shaik Mohammed Zakeeruddin

A novel nanocomposite bead based on polymeric matrix of carboxymethyl cellulose and copper oxide-nickel oxide nanoparticles was synthesized, characterized, and applied for adsorptive removal of inorganic and organic contaminants at trace level of part per ...

SPRINGER HEIDELBERG2021

Near ambient-pressure X-ray photoelectron spectroscopy study of CO2 activation and hydrogenation on indium/copper surface

Andreas Züttel, Wen Luo, Mo Li

Indium-based catalysts exhibit excellent performance for CO2 hydrogenation to methanol, yet their nature and chemical evolution under reaction conditions are still elusive, thus hindering an understanding of their reaction mechanism. In this work, near amb ...

2021

Gold-in-copper at low *CO coverage enables efficient electromethanation of CO2

Michael Graetzel, Dan Ren, Jun Li

The renewable-electricity-powered CO2 electroreduction reaction provides a promising means to store intermittent renewable energy in the form of valuable chemicals and dispatchable fuels. Renewable methane produced using CO2 electroreduction attracts inter ...

Nature Research2021

Influence of thermo-mechanical processing on ordering kinetics in 18 karat red gold alloy

Marina Garcia Gonzalez

The aim of this project is to understand the correlation between alloy composition and the build-up of internal stresses in 18 carat Au-Ag-Cu alloys under thermo-mechanical loads. The copper rich end of this ternary system exhibits order-hardening of the e ...

EPFL2020

The thermally activated distortion with amplification effect and related variant selection in red gold alloys

Roland Logé, Cyril Cayron, Margaux Nathalie Dominique Larcher

Variant selection during the A1→L10 transformation in a polycrystalline red gold alloy close to equiatomic Au-Cu composition has been extensively studied by Electron Backscatter Diffraction (EBSD) in our previous work. The use of a mathematical description ...

2020

Mapping of Chemical Heterogeneity at Surfaces with High-Throughput Wide-Field Second Harmonic Microscopy

Igor Nahálka

Many industrial processes are based on electrochemical reactions using engineered electrocatalysts. However, the current lack of theoretical knowledge obscures efforts to maximize catalysts' efficiency, and the optimization process is mostly empirical. To ...

EPFL2020

Tribological Approach to the Watch Movements

Valentine Agnès Madeleine Magnin

Mechanical watches are complex and sensitive systems that have to maintain a faultless precision over their lifetime. However, this precision can be altered by disturbances occurring during the functioning time, such as friction, lubricant drying, or wear, ...

EPFL2020

Influence of Ir Additions and Icosahedral Short Range Order (ISRO) on Nucleation and Growth Kinetics in Au-20.5Wt Pct Cu-4.5Wt PctAg Alloy

Michel Rappaz

Based on detailed EBSD analyses, Kurtuldu et al. (Acta Mater. 70:240-248, 2014) have explained the grain refinement of Au-12.5 wt pctCu-12.5 wt pctAg (yellow gold) by the addition of minute amounts of Ir in terms of icosahedral quasicrystal (iQC)-mediated ...

SPRINGER2019

Appearance of polished 18 karat gold surfaces: linking aesthetics to surface features

Leili Batooli

Impeccable appearance of surfaces is a key constraint in high-end jewelry and watch manufacturing. Based on long tradition in the industry, appearance of products is assessed by trained individuals through visual inspection in designated intervals on the p ...

EPFL2019

Influence of minor additions on Icosahedral Short-Range Order (ISRO) and its consequences on nucleation and solidification growth kinetics in fcc alloys

Michel Rappaz

The present contribution reviews the recent progress related to the influence of Icosahedral Short-Range Order (ISRO) and icosahedral Quasicrystals (i-QC) formation on the solidification of fcc alloys through minor solute element additions. From intensive ...

IOP PUBLISHING LTD2019

Tribological response of multilayered gold nickel coating deposited on fine turned surfaces

Stefano Mischler, Valentine Agnès Madeleine Magnin

Gold coating are widely used in industry due to their corrosion resistance, electrical conductivity and low contact resistance. However, friction and wear can limit their functionality and lifetime. This study addresses the degradation of a commercial fine ...

ELSEVIER SCIENCE SA2019

Predicting the reflectivity and colour of metals from first principles

Gianluca Prandini

Gold and copper are the only two elemental metals that show a characteristic colour, due to the presence of a drop in the reflectivity curve inside the visible range. Reflectivities of all other metals are in general high and flat for all visible frequenci ...

EPFL2019

Enhanced precipitate growth at reduced temperatures during chemical ordering in deformed red gold alloys

Nadine Baluc, Steven Van Petegem, Helena Van Swygenhoven, Samy Hocine, Marina Garcia Gonzalez

Manufacturing of red gold components relies widely on controlling the formation of ordered precipitates during thermo-mechanical processing. The ordered phase hardens the material, makes it less workable and introduces residual stresses. We show that an in ...

PERGAMON-ELSEVIER SCIENCE LTD2019