Palladium

Platinum Metals Review, 2005

Mineralogical Magazine, 2013

Chemical and structural data are reported for platinum-palladium intermediates from two nuggets found at Có rrego Bom Sucesso, Minas Gerais, Brazil. Three grains with simple stoichiometries (i.e. Pt x Pd 1Àx with x~0.67,~0.5 and~0.33, which correspond to Pt 2 Pd, PtPd and PtPd 2 , respectively) were characterized by single-crystal X-ray diffraction and electron-probe microanalysis. In the absence of single-crystal data it might be tempting to hypothesize that such simple stoichiometries represent distinct mineral species, however structural analyses show that all of the phases are cubic and crystallize in space group Fm3m. They are, therefore, natural intermediates in the palladium-platinum solid solution. Reflectance and micro-hardness values are reported for the samples and a comparison with the pure metallic elements made. On the basis of information gained from the chemical and structural characterization it can be concluded that there is a complete solid solution between Pt and Pd in nature. These findings corroborate results from experiments on synthetic compounds.

2006

The metal printing process, MPP; is a novel Rapid Manufacturing process under development at SINTEF and NTNU in Trondheim, Norway. The process, which aims at the manufacturing of end-use products for demanding applications in metallic and CerMet materials, consists of two separate parts; The layer fabrication, based on electrostatic attraction of powder materials, and the consolidation, consisting of the compression and sintering of each layer in a heated die. This approach leads to a number of issues regarding the interaction between the process solutions and the materials. This paper addresses some of the most critical material issues at the current development stage of MPP, and the present solutions to these.

Inkjet printing is used to deposit palladium films with different morphologies and electrical properties using different precursor thermolysis atmospheres. First, the precursor is reductively decomposed into amine-stabilized palladium clusters. In air, oxygen assists the decomposition of the organoamine ligands for the palladium clusters. Small nanoparticles are formed and fused to smooth films. In nitrogen, the residual ligands facilitate the formation of sub-micron spherical aggregates. In low vacuum, a bilayer film containing a bottom layer with fused nanoparticles and a top layer with spherical aggregates is formed. Such morphology is caused by the competition between the film formation processes in air and in nitrogen. The electrical properties of the films are determined by the whole film for the smooth film and by the bottom layer for the bilayer film. The temperature coefficient of resistance of the films can be adjusted from 0.067% /°C to -0.189% /°C by tuning the amount of semiconductive palladium oxide in the conduction path. In addition, humid air increases the resistance drift of the films by forming surface-adsorbed hydroxyl groups and/or molecular water. This study highlights the importance of precursor thermolysis atmosphere on the morphology and electrical properties of inkjet-printed palladium/palladium oxide films.

Revista de Metalurgia, 2015

In order to broaden future application of products based on platinum and palladium a comparative analysis of their high-temperature mechanical properties was performed. Platinum and palladium are of great importance and are widely used in chemical industry, electronics, for making laboratory dishes, to name a few. Mechanical properties of pure metals, such as: tensile strength, creep rate and rupture time were investigated using universal testing machine for tensile testing of materials. Microstructure of samples was investigated by optical microscopy. Based on obtained results it can be concluded that the platinum, compared to palladium, is superior for high-temperature applications.

Ultramicroscopy, 2013

A major practical challenge in heterogeneous catalysis is to minimize the loading of expensive platinum group metals (PGMs) without degrading the overall catalytic efficiency. Gaining a thorough atomicscale understanding of the chemical/structural changes occurring during catalyst manufacture/operation could potentially enable the design and production of ''nano-engineered'' catalysts, optimized for cost, stability and performance. In the present study, the oxidation behavior of a Pt-31 at% Pd alloy between 673-1073 K is investigated using atom probe tomography (APT). Over this range of temperatures, three markedly different chemical structures are observed near the surface of the alloy. At 673 K, the surface oxide formed is enriched with Pd, the concentration of which rises further following oxidation at 773 K. During oxidation at 873 K, a thick, stable oxide layer is formed on the surface with a stoichiometry of PdO, beneath which a Pd-depleted (Pt-rich) layer exists. Above 873 K, the surface composition switches to enrichment in Pt, with the Pt content increasing further with increasing oxidation temperature. This treatment suggests a route for tuning the surfaces of Pt-Pd nanoparticles to be either Pd-rich or Pt-rich, simply by adjusting the oxidation temperatures in order to form two different types of core-shell structures. In addition, comparison of the oxidation behavior of Pt-Pd with Pt-Rh and Pd-Rh alloys demonstrates markedly different trends under the same conditions for these three binary alloys.

Sensors and Actuators A: Physical, 2002

Two lift-off methods were developed for patterning platinum ®lms deposited at 400 8C via DC magnetron sputtering. Both methods are based upon the formation of multiple-layer metal lithography masks. Ti/Al and Cr/Al masks were fabricated such that the Ti or Cr layer overhangs the aluminum base layer. When using a Ti/Al lithography mask, the patterned platinum lines were broadened and the line resolution was low. Higher line resolution and cleaner line edges were obtained when a Cr/Al mask was used.

International Platinum …

to the quaternary alloys to change selected properties. As well as developing the alloys themselves, another part of the project is to compile a thermodynamic database using Thermo-Calc™. Phase diagram work has been undertaken so that the results can be input to Thermo-Calc™ so that the descriptions of the phases can be optimized. The final database will allow the phases and compositions of selected alloys to be derived, thus predicting the alloys' components without necessarily undertaking further experimental work. This will aid the development of the alloys and will be a useful tool to the final developers of the alloys. Good agreement with experimental data has been observed, which is very encouraging for usefulness of the database.

2019

Alloys of Platinum Group Metals (PGM) show outstanding characteristics for jewellery and watch making: they are precious, strong and white. 50Pt50Rh is one of the most outstanding alloys for high-end jewellery with a hardness of up to 400 HV, tensile strength up to 1200 MPa and a yellowness index of 8. At the same time, these alloys represent the most challenging materials with respect to processing, refining and high costs in capital. Powder metallurgy (PM) of PGMs is an essentially different processing practice from conventional manufacturing. We would like to give an insight into the production of platinum and palladium powders and their processing by additive manufacturing (AM) respectively laser metal fusion (LMF). Topics to be discussed cover comparisons of popular and new alloys including their material properties with respect to colour, microstructure, mechanical properties and workability. Many indicators suggest that product manufacturing from platinum and palladium alloys...

2010

to the quaternary alloys to change selected properties. As well as developing the alloys themselves, another part of the project is to compile a thermodynamic database using Thermo-Calc™. Phase diagram work has been undertaken so that the results can be input to Thermo-Calc™ so that the descriptions of the phases can be optimized. The final database will allow the phases and compositions of selected alloys to be derived, thus predicting the alloys' components without necessarily undertaking further experimental work. This will aid the development of the alloys and will be a useful tool to the final developers of the alloys. Good agreement with experimental data has been observed, which is very encouraging for usefulness of the database.