Alloy information helps prioritize material criticality lists

Materials scientists employ metals and alloys that involve most of the periodic table. Nonetheless, materials scientists rarely take material criticality and reuse potential into account. In this work, we expand upon lists of “critical materials” generated by national and regional governments by showing that many materials are employed predominantly as alloying elements, which can be a deterrent to recovery and reuse at end of product life and, likely as a consequence, have low functional end-of-life recycling rates, among other problematic characteristics. We thereby single out six metals for enhanced concern: dysprosium, samarium, vanadium, niobium, tellurium, and gallium. From that perspective, the use of critical metals in low concentrations in alloys unlikely to be routinely recycled should be avoided if possible. If not, provision should be made for better identification and more efficient recycling so that materials designated as critical can have increased potential for more than a single functional use.

Heavy Loaded Parts of Petrochemical Equipment Destruction Cause Investigation

The problem of using specialized passivating metals and alloys lies in a rather narrow range of the protecting film performance. With a slight change in operating conditions, the film is destroyed and an avalanche-like process of local corrosion begins at the place of film breakdown. A sequence has been developed for determining parts destruction causes, including a sequential analysis of operating conditions; nature of the part destruction; corrosion products composition; phase inversion in the alloy during overheating or mechanical stress in the part.

Development of a method for calculating the LTEC anisotropy of Zr alloys

The accuracy of determining the LTEC with respect to metals and alloys with an HCP lattice based on inverse pole figures (IPF) is analyzed depending on the number of experimental points on the IPF using three averaging options: (1) taking into account the irregular arrangement of reflections on the stereographic triangle according to Morris; (2) by the multiplicity factor and (3) with the same weight of each orientation. It is shown that when evaluating the LTEC for semi-finished products with a basal texture, 17 reflections on the IPF are sufficient to provide an error of <1% when using Morris averaging and the multiplicity factor; in the case of a prismatic texture, an error of <1% is provided by all three averaging options, while Morris averaging is minimal.

Creep and Deformation of Metals and Alloys at Elevated Temperatures

Various aspects of creep and deformation behaviors of metals and alloys at elevated temperatures are of great interest to materials scientists [...]

Monitoring of the atmospheric corrosivity by resistive sensors

Atmospheric corrosivity is classified according to EN ISO 9223 Corrosion of metals and alloys – Corrosivity of atmospheres – Classification, determination and estimation. For the determination and estimation of the corrosivity category, standardized approaches are used. Monitoring of corrosivity with the application of various sensors is an actual trend. The paper gives results of verification of some types of sensors for this monitoring with standardized flat samples at atmospheric test sites in the Czech Republic. The trend of decreasing atmospheric corrosivity is evident in the last decade. Monitoring of the corrosion rate and mapping of the corrosivity become a very important step in preventing failures in long-term atmospheric exposition. This type of monitoring was used on bridge construction to estimate the seasonal effect of de-icing salts deposition, too.