Alloy

About: Alloy is a research topic. Over the lifetime, 171884 publications have been published within this topic receiving 1719420 citations. The topic is also known as: alloys.

Microstructure and phase stability of INCONEL alloy 617

Abstract: INCONEL alloy 617 (54 Ni, 22 Cr, 12.5 Co, 9 Mo, 1 Al, 0.07 C) is a solid-solution alloy with good corrosion resistance and an exceptional combination of high-temperature strength and oxidation resistance. A laboratory study was performed to determine the effects of long-time (215 to over 10,000 h) exposure to temperatures up to 2000°F (1093°C) on the microstructure and phase stability of the alloy. To investigate the strengthening response exhibited by the alloy during high-temperature exposure, microstructures were correlated with mechanical properties. The major phase present in the alloy after exposure to all temperatures from 1200 to 2000°F (649 to 1093°C) was found to be M23C6. The phase precipitated as discrete particles and remained stable at au temperatures. No MC or M6C carbides were found. A small amount of gamma prime was found in samples exposed at 1200°F (649°C) and 1400°F (760°C). A PHACOMP analysis indicated 0.63 pct gamma prime could form. No topological close-packed phases such as sigma, mu, and chi were found. Strengthening of the alloy during exposure to temperature was found to result primarily from the precipitation of M23C6. The phase provides effective strengthening because it precipitates in discrete particles and remains stable at temperatures to 2000°F (1093°C). The amount of gamma prime formed is not sufficient to cause appreciable hardening, but it does provide some strengthening at 1200 to 1400°F (649 to 760°C).

Microstructure and Compressive Properties of NbTiVTaAl x High Entropy Alloys

Abstract: The novel refractory high entropy alloys with the compositions of NbTiVTaAl x were prepared under a high-purity argon atmosphere and their microstructure and compressive properties at room temperature were investigated. Despite containing many constituents, all alloys had a single solid solution phase with body-centered cubic (BCC) structure, and possessed high compressive yield strength and ductility, which should be attributed to solid solution strengthening. © 2011 Published by Elsevier Ltd. Selection and/or peer-review under responsibility of MRS-Taiwan Keywords: High entropy alloy; solid solution; yield strength; ductility; solid solution strengthening 1. Introduction Recently, high-entropy alloys (HEAs), defined as alloys that generally have at least 5 major metallic elements and each of which has an atomic percentage between 5 % and 35% [1], have attracted increasing attentions. According to the regular solution model, the alloys have very high entropy of mixing, which makes HEAs usually form FCC and/or BCC solid solutions rather than intermetallic compounds or other complex ordered phases, and the total number of phases is well below the maximum equilibrium number allowed by the Gibbs phase rule [1-4]. In the past decade, a number of these HEAs have been explored

Dehydrogenation of TiH2

Abstract: Hydrogen is a unique alloying element for titanium because it can be introduced into the metal to form solid solutions or stoichiometric compounds by exposure to the gas at elevated temperatures and removed by vacuum annealing Studies on dehydrogenation of fine titanium hydride are important for several applications such as thermohydrogen processing of Ti and Ti based alloy components, hydrogen storage materials and bonding of metals and ceramics using TiH2 Effect of particle size on dehydrogenation of TiH2 is studied here, using thermal analysis along with structural investigations Dehydrogenation of nanocrystalline hydride powder differs considerably from the micron size starting powder A two step dehydrogenation process, (TiH2 → TiHx → α-Ti) where 07