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.

Investigation and Discussion of Characteristics for Intermetallic Phases Common to Aluminum Alloys as a Function of Solution pH

Abstract: This paper presents results for corrosion potentials, pitting potentials, and electrochemical characteristics for intermetallic particles commonly present in high strength aluminum-based alloys, for tests conducted in a 01 M NaCl solution of varying pH via the use of a microcapillary electrochemical cell The intermetallics investigated were Mg2Si, MgZn2 ,A l7Cu2Fe, Al2Cu, Al2CuMg, and Al3Fe Elaboration of the results reveals that the electrochemical behavior of such compounds varies markedly with pH, with attendant ramifications for localized corrosion and protection in Al alloys Examples of this are shown for AA7075-T651, where it is shown that the localized corrosion morphology is drastically different upon the bulk alloy depending on the pH of the test environment A stochastic pitting is observed at an acid pH, near-neutral conditions result in a deterministic-type pitting, and a general corrosion is observed at an alkaline pH

On the nature of T(Al2Mg3Zn3) and S(Al2CuMg) phases present in as-cast and annealed 7055 aluminum alloy

Abstract: Aluminum alloys, encompassed by AA 7055 alloy composition, having the nominal zinc content (i.e. 8 wt.%) but varying copper and magnesium contents across the alloy composition range were examined in the as-cast form by a combination of light microscopy, scanning electron microscopy (SEM), electron probe micro analysis (EPMA) and X-ray diffraction (XRD). It is observed that for all compositions, the second phases based on η(MgZn2), T(Al2Mg3Zn3) and S(Al2CuMg) are present. The T phase dissolves copper up to 28 wt.%, whilst the S phase shows metastable solubility of zinc that may range up to 30 wt.%. In alloys with magnesium at the lower limit and the copper contents approaching the upper limit of the alloy composition, the θ phase (Al2Cu) of the constituent binary Al–Cu system is further observed. The θ phase (Al2Cu) does not dissolve either zinc or magnesium. Below the nominal composition, the alloys could be homogenized substantially using a commercially viable homogenization treatment leaving small amounts of undissolved S phase that does not contain any zinc.

Molecular dynamics study of the binary Cu_(46)Zr_(54) metallic glass motivated by experiments: Glass formation and atomic-level structure

Abstract: We have identified a binary bulk metallic glass forming alloy Cu_(46_Zr_(54) by analyzing the structure and thermal behaviors of copper mold cast samples using x-ray diffraction, transmission electron microscopy, and differential scanning calorimeter. Motivated by these experimental results, we fitted the effective Rosato-Guillope-Legrand-type force field parameters for the binary Cu-Zr alloy system and the atomistic description of glass formation and structure analysis of the Cu_(46)Zr_(54) alloy based on molecular dynamics simulation will be also presented.

Influence of Al on the Microstructural Evolution and Mechanical Behavior of Low-Carbon, Manganese Transformation-Induced-Plasticity Steel

Abstract: Microstructural design with an Al addition is suggested for low-carbon, manganese transformation-induced-plasticity (Mn TRIP) steel for application in the continuous-annealing process. With an Al content of 1 mass pct, the competition between the recrystallization of the cold-rolled microstructure and the austenite formation cannot be avoided during intercritical annealing, and the recrystallization of the deformed matrix does not proceed effectively. The addition of 3 mass pct Al, however, allows nearly complete recrystallization of the deformed microstructure by providing a dual-phase cold-rolled structure consisting of ferrite and martensite and by suppressing excessive austenite formation at a higher annealing temperature. An optimized annealing condition results in the room-temperature stability of the intercritical austenite in Mn TRIP steel containing 3 mass pct Al, permitting persistent transformation to martensite during tensile deformation. The alloy presents an excellent strength-ductility balance combining a tensile strength of approximately 1 GPa with a total elongation over 25 pct, which is comparable to that of Mn TRIP steel subjected to batch-type annealing.

The atomic structure of alloy surfaces and surface alloys

Abstract: This paper reviews the available data about the structure of bimetallic surfaces where the constituent elements are intermixed at atomic level. These systems include the surface of bulk alloys ('alloy surfaces') and systems resulting from diffusion at metal-metal interfaces ('surface alloys'). All cases where a complete surface crystallographic determination exists are listed and discussed, as well as selected cases where the structural data are not complete but can lead to a model of the atomic structure.