Microstructure-Based Estimation of Strength and Ductility Distributions for $$\alpha +\beta $$ Titanium Alloys

Titanium alloys are processed to develop a wide range of microstructure configurations and therefore material properties. While these properties are typically measured experimentally, a framework for property prediction could greatly enhance alloy design and manufacturing. Here a microstructure-sensitive framework is presented for the prediction of strength and ductility as well as estimates of the bounds in variability for these properties. The framework explicitly considers distributions of microstructure via new approaches for instantiation of structure in synthetic samples. The parametric evaluation strategy, including the finite element simulation package FEpX, is used to create and test virtual polycrystalline samples to evaluate the variability bounds of mechanical properties in Ti-6Al-4V. Critical parameters for the property evaluation framework are provided by measurements of single crystal properties and advanced characterization of microstructure and slip system strengths in 2D and 3D. Property distributions for yield strength and ductility are presented, along with the validation and verification steps undertaken. Comparisons between strain localization and slip activity in virtual samples and in experimental grain-scale strain measurements are also discussed.

     

Substrate Stimulated Orientation for Pure Aluminum

Oriented materials are of great importance, but their formation is rarely described. Here, nine Al/Al₂O₃ systems were designed to identify the dominant factors. Electron back-scattered diffraction indicates that the new Al crystal(s) with one or multiple orientation(s) can be stimulated by one single-crystal Al₂O₃ substrates. Synchrotron radiation diffraction shows that the preferred orientation(s) is/are determined based on the initial stage of the liquid–solid transition. The nonpreferred orientation can be suppressed through competition.

     

Accelerated Design of Eutectic High Entropy Alloys by ICME Approach

Eutectic high entropy alloy with seven components is designed based on the integrated computational materials engineering (ICME) framework. The framework includes thermodynamic prediction using calculation of phase diagrams (CALPHAD), microstructure simulation using phase-field method, and experimental validation. The designed alloy shows the eutectic structure consisting of FCC and laves phase in the composition range from 8.25 to 10 at. pct Ta. The simulation and experimental results are co-related and a framework is proposed that can be used for high entropy alloy design subjected to various manufacturing processes.

     

Microstructural Features of Low-Alloy Pipeline Steels that Determine Impact Strength of Welded Joint Heat-Affected Zone

Metallurgist - Microstructural mechanisms reducing the impact strength values of a coarse grained heat-affected zone are studied for two K60 microalloyed steels. Research is conducted on specimens...     

Sintering and Briquetting Synergy in Blast Furnace Smelting

Metallurgist - The article describes the concept of partially replacing the sinter in a blast furnace charge with extrusion briquettes to form the basis for sintering and briquetting synergy. The...     

Remelting of Iron Shavings with the Synergistic Effect of Minimum Metal Loss

Metallurgist - The well-known technologies of remelting iron shavings lead to significant (30%) losses of metal. An electroslag smelting furnace with graphite electrodes is proposed for remelting...     

Combustion in Ni–Al System with Cu Additive (Powder or Rod). Experiment and Mathematical Model

Russian Journal of Non-Ferrous Metals - Experimental studies have been carried out with theoretical calculations of wave synthesis in the Ni–Al–Cu system using a mathematical model....     

Ensuring Strength in Laser Welds Made Using the Dispersion-Hardened EP693 Nickel Alloy

Russian Journal of Non-Ferrous Metals - The process of making a weld using the heat-resistant EP693 alloy (Ni–Cr–W–Co–Co–Mo system) to make assemblies and components...     

Grain Refinement of Casting Aluminum Alloys of the Al–Mg–Si System by Processing the Liquid Phase Using Nanosecond Electromagnetic Pulses

Russian Journal of Non-Ferrous Metals - In this paper, using the AA 511 alloy of the Al–Mg–Si system as an example, it is shown that the irradiation of aluminum melts with nanosecond...     

The Influence of Hydrogen Concentration in an Ar–H2 Mixture on the Electrical Properties of Solid Oxide Fuel Cells

Powder Metallurgy and Metal Ceramics - Fuel cells are today among the most efficient and environmentally friendly devices for the production of electricity. They are developing rapidly and are...