Scientific Events

Room: BDS Seminar room

MPIE-Kolloquium: Sustainable Molten Salt Route for Electro-extraction & Electro-refining of Low-grade Ores to Yield High Purity Titanium

Sustainable Molten Salt Route for Electro-extraction & Electro-refining of Low-grade Ores to Yield High Purity Titanium
Titanium is the fourth most abundant engineering material in the Earth’s crust. Although it has many beneficial properties, the cost of extraction remains a challenge and over 90% of high grade titanium is derived from the expensive and time-consuming Kroll Process. Electro-refining methods show promise but present their own special challenges. We present an overview and update of a novel molten salt process to extract and refine low-grade ores to produce high-grade powder titanium. Titanium oxycarbide produced by carbothermic reduction is electro-refined in a molten eutectic bath of NaCl:KCl salt. Anodic dissolution causes the Ti product to be plated out in the form of a dendritic product which collects on the cathode while impurities are retained in the anode. A gentle introduction to the process will be given and recent studies to apply the method to include the effect of using ilmenite and ilmenite/rutile blends as a feedstock, as well as the applicability of the process to other metals, specifically niobium (Nb) and vanadium-baring minerals presented. [more]

Opportunities for bcc refractory-metal superalloys

Reinforcement with ordered intermetallic precipitates is a potent strategy for the development of strength alongside damage tolerance and is central to the success of fcc nickel-based superalloys. Such a strategy is equally of interest within bcc-based systems for their increased melting point and acceptable cost. However, only limited studies have been made on refractory metal (RM) or titanium based alloys strengthened by ordered-bcc precipitates (e.g. B2 or L21). Are such “bcc superalloys” possible? Do they offer useful properties? In this talk, opportunities for refractory-metal-based superalloys systems will be discussed, including a review of Cr-Ni2AlTi, Mo-NiAl, Ta-(Ti,Zr)2Al(Mo,Nb) and Nb-Pd2HfAl systems together with newly developed alloys. These alloys exploit an extensive two-phase field that exists between A2 (RM,Ti) and B2 TiFe to produce nanoscale precipitate reinforced microstructures that increase strength by over 500 MPa. This work was supported through EUROfusion Researcher Grant & EPSRC Doctoral Prize Fellowships, EPSRC ‘DARE’ (darealloys.org) EP/L025213/1 and Rolls-Royce/EPSRC Strategic Partnership EP/H022309/1 and EP/H500375/1. [more]

Application of Scientific Principles to Aluminium Automotive Sheet

Abstract Aluminium has been used in the manufacture of automobiles for more than 100 years and current usage averages more than 150kg per vehicle. Recent demands for higher fuel economy, improved vehicle performance, and lower CO2 emissions are currently driving a dramatic increase in the usage of specially designed aluminium alloys in the automotive industry. Aluminium flat-rolled sheet products are currently seeing wide-spread application for many components previously produced from steel. The technical requirements for aluminium sheet include high levels of formability, high strength, corrosion resistance, surface appearance, and long term reliability of joints. While these requirements are often in direct conflict, improved understanding of microstructure and surface has enabled the economical production of sheet that can meet the necessary customer demands. Three key developments in metallurgy and surface science that have made aluminium automotive sheet possible are reviewed: control of precipitate morphology for high strength, surface microstructure for bond durability, and crystallographic texture for surface appearance after forming. [more]

Diffusion and segregation of solutes in grain boundaries: from pure metals to high-entropy alloys

Diffusion and segregation of solutes in grain boundaries: from pure metals to high-entropy alloys

Nitride coatings based on high-entropy alloys

Nitride coatings based on high-entropy alloys
The new alloying concept, known as high-entropy alloys (HEAs) or multi-principal elements alloys (MPEAs) are a new emerging class of perspective materials that possess a wide range of unique properties. Since the appearance of the first studies of HEAs, more than 1000 scientific works were published. It was investigated relationship between microstructure of new alloys, which can include SS (with BCC, FCC and HCP structures), IM and even amorphous state and their physical properties. It was shown that the HEAs possess different outstanding functional properties, like superconductivity with transition temperature Tc = 7.3 K, high level electrical resistivity, high saturated magnetization, high corrosion resistance, good hydrogen storage properties, as a template for graphene production. For achievement superior mechanical behavior and thermal stability it was designed and produced protective coatings based on HEAs. However, the research of nitride coatings based on HEA are still very limited. Clearly, the understanding of features of microstructure such non-homogeneous complex systems is essential in order to move in the improvement of the physical properties of high-entropy thin films with different intrinsic architecture. [more]

Symposium “Environmental, in-situ and time-resolved microscopy” at MC 2017 (Microscopy Conference 2017)

Symposium “Environmental, in-situ and time-resolved microscopy” at MC 2017 (Microscopy Conference 2017)

The Search For Charge Density Based Structure-Property Relationships

The Search For Charge Density Based Structure-Property Relationships
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