Predicting phase equilibrium,phase transformation,and microstructure evolution in titanium alloys

Phase transformation and microstructural evolution in commercial titanium alloys are extremely complex. Traditional models that characterize microstructural features by average values without capturing the anisotropy and spatially varying aspects may not be sufficient to quantitatively define the microstructure and hence to allow for establishing a robust microstructure-property relationship. This article discusses recent efforts in integrating thermodynamic modeling and phase-field simulation to develop computational tools for quantitative prediction of phase equilibrium and spatiotemporal evolution of microstructures during thermal processing that account explicitly for precipitate morphology, spatial arrangement, and anisotropy. The rendering of the predictive capabilities of the phase-field models as fast-acting design tools through the development of constitutive equations is also demonstrated. For more information, contact Y.-Z. Wang, Department of Materials Science & Engineering, Ohio State University, 2041 College Road, Columbus, OH 43221, USA; (614) 292-0682; fax (614) 292-1537; e-mail wang.363@osu.edu.     

Water-Acetonitrile Ratio in Perchlorate Cadmium Bath and the Effectiveness of the Addition of Crown-Ester

It is shown that the strongest deceleration of the electrodeposition of cadmium in inhibited media is observed in the domain of loosening the structure of a mixed solvent (0.45 x ₂ 0.25) when the molecular adsorption of organic solvent on Cd is maximum. The process is maximally facilitated in the domain of ordering the acetonitrile's (AN) structure (0.9 x ₂ 0.75), where perchlorate anions dominate at the cathode surface. Crown-ester exhibits maximum inhibition effect under the conditions of preferential adsorption of its molecules, i.e., in the domain of the prevalence of the nonaqueous component in the mixture (x ₂ 0.95).     

Change in structure of an iron-chromium alloy during service

Conclusions As the result of long high-temperature heating the structure of the iron-chromium alloy changes. After service at 1280–1300°C for 500 h light precipitates at the boundaries and in the body of the grain enriched with chromium and molybdenum are observed, which may be considered as the result of separation of the ferrite and as a preparatory stage before precipitation of -phase. In the surface zones of the feeder, nitride and oxide inclusions and products of gas corrosion are observed.Institute of Problems of Casting, Academy of Sciences of the Ukrainian SSR. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 1, pp. 29–30,January, 1985.     

Metallic compounds in the Ti−Cu system

Conclusions In alloys of the Ti–Cu system we found the Ti₃Cu phase at a concentration of 25 at % Cu formed at 1000°C by the peritectic reaction L+Ti₃Cu.Siberian Metallurgical Institute. Translated from Metallovedenie i Termicheskaya Obrabotka Metallov, No. 2, pp. 10–11, February, 1967.     

Preparation,Properties and Applications of the Hybrid Organic/Inorganic Nanocomposite Based on Nanoporous Carbon Matrix

Journal of Inorganic and Organometallic Polymers and Materials - Nanoporous carbon matrix was prepared by the sol–gel process from pyrogallol-formaldehyde (PF) mixtures in water using picric...     

Mechanical and Corrosion Properties of ZrB2–SiC Composite Ceramics with Oxide Additions

Powder Metallurgy and Metal Ceramics - Hot pressing was used to produce compact ceramic samples with the following composition (wt.%): 60 ZrB2 + 20 SiC + 20 (Al2O3 + 32 t-ZrO2). The tetragonal...     

A Heat Treatment to Produce a Coarse-α-Particle Size in Ti–6Al–4V

Metallurgical and Materials Transactions A - A heat-treatment method to develop a coarse-α-particle size in Ti–6Al–4V with a fully-globular (equiaxed) microstructure was developed....     

Processing a Sn–Pb Alloy to Produce Tin

Russian Journal of Non-Ferrous Metals - The aim of the work is to develop an optimal method for processing Sn–Pb alloy to obtain a marketable product-branded O1?O3 tin (Sn ≥...     

Interaction of Components in Glass-Forming Melts of Iron and Nickel with Titanium,Zirconium, and Hafnium II. Temperature–Concentration Dependence of Thermodynamic Mixing Functions of Liquid Alloys

Powder Metallurgy and Metal Ceramics - The thermodynamic properties of liquid alloys in glass-forming systems were described in the framework of the associated solution model (ASM) according to the...     

Using mineralogy to optimize gold recovery by direct cyanidation

The complete and accurate gold deportments of direct cyanide leach residues provide a clear picture of the occurrence of unrecovered gold and identify causes for poor extraction. Based on the independent measurement of each form and carrier of unleached gold, opportunities for recovery optimization can be assessed more accurately by providing meaningful targets and can help identify the means to achieve such targets. In ten of 14 leach plants surveyed, 23% of the unrecovered gold could be extracted without finer grinding. For more information, contact S. Chryssoulis, AMTEL, 205-100 Collip Circle, London, Ontario, Canada N6G 4X8; (519) 858-5037; fax (519) 858-5038; e-mail amtel@skynet.ca.