A1-L1&lt;sub&gt;2&lt;/sub&gt; Structures in the Al-Co-Ni-Ti Quaternary Phase System

Minshull, J. P.; Neumeier, Steffen; Tucker, Matthew G.; Stone, H.J.

doi:10.4028/www.scientific.net/amr.278.399

Cited by 19 publications

(19 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such modifications were shown to confer benefits to both the strength and microstructural stability of both cast & wrought [47][48][49][50][51] and powder processed [52,53] alloys. In parallel, fundamental studies of the underpinning Ni -CoAl -Ti system were performed and determined that the A1 -L1 2 two-phase field is continuous between Ni -Ni 3 Al and Co -Co 3 Ti [54,55]. More recently, Oni et al [56] employed a range of advanced characterisation techniques to study the site occupancies and lattice misfit strains in quaternary Ni-Co-Al-Ti alloys, and demonstrated a more complicated partitioning and site occupancy behaviour for Co than initially expected.…”

Section: Introductionmentioning

confidence: 99%

The microstructure and hardness of Ni-Co-Al-Ti-Cr quinary alloys

Christofidou

Jones

Pickering

et al. 2016

Journal of Alloys and Compounds

View full text Add to dashboard Cite

The effects of Ni:Co and Al:Ti ratios on the room temperature microstructure, hardness and lattice parameter of twenty-seven quinary Ni-Co-Al-Ti-Cr alloys have been evaluated. All of the alloys exhibited a uniform γ-γ′ microstructure. Differential scanning calorimetry (DSC) showed that the liquidus and solidus temperatures of the alloys, increase with greater Al:Ti ratios, decrease with Cr concentration and remained largely unchanged with respect to the Ni:Co ratio. Neutron diffraction measurements of the γ and γ′ lattice parameters revealed that the lattice misfit in all of the alloys was positive and increased with Ti concentration (i.e. lower Al:Ti ratio) regardless of the concentration of Cr, or the ratio of Ni:Co. Importantly, alloys with a Ni:Co ratio of 1:1, were found to have consistently greater lattice misfits than alloys with Ni:Co ratios of either 1:3 or 3:1. The measured lattice misfits were found to be strongly correlated with the Vickers hardness of the alloys, suggesting that lattice misfit plays a key role in the strengthening of γ-γ′ alloys of this type.

show abstract

Section: Introductionmentioning

confidence: 99%

The microstructure and hardness of Ni-Co-Al-Ti-Cr quinary alloys

Christofidou

Jones

Pickering

et al. 2016

Journal of Alloys and Compounds

View full text Add to dashboard Cite

show abstract

“…[14] From the lattice constants of the phases, a g and a g 0 , the lattice misfit d was calculated then by the following formula: A specimen with a diameter of 5 mm was investigated in transmission geometry with a photon energy of 87 keV (l ¼ 0.1425 A ).…”

Section: Methodsmentioning

confidence: 99%

Influence of Iridium on the Properties of γ′‐Strengthened Co‐Base Superalloys

et al. 2014

Self Cite

View full text Add to dashboard Cite

The influence of iridium on the phase stability, oxidation behavior, and high temperature creep strength of g 0 -hardened Co-base superalloys is discussed. Ir increases the g 0 -solvus temperature and g 0 -volume fraction since it partitions slightly to the g 0 -phase. However, Ir leads also to a discontinuous precipitation transformation of the metastable g/g 0 -microstructure into a lamellar microstructure of Co 3 W, CoAl, and a Co-rich fcc phase for the W-rich alloys. A reduction of W in presence of Ir leads to a higher phase stability. The constrained lattice misfit between the g and g 0 phase in the Ir and high W containing alloy is þ0.5%. The alloying element Ir strongly increases the creep strength at 850°C as long as the g/g 0 -microstructure is not discontinuously transformed. Furthermore, the oxidation resistance is improved by the addition of iridium.

show abstract

“…Kuhn et al pointed out that the matrix channels running perpendicular and parallel to the stress axis [001], respectively, contribute in different ways to the reflection profile due to the tetragonal distortion of γ due to coherency stresses [17]. Neutron diffraction measurements on homogeneous Ni-Co-Al-Ti alloys with high lattice misfit [18] and X-ray experiments by Royer et al [19] have confirmed that high coherency stresses in the matrix channels leads to a tetragonal distortion of the γ matrix. The fact that all alloys investigated in this study possess the same Re content and have been subjected to similar solution heat treatments suggests that a similar residual Re segregation may be expected between the alloys.…”

Section: Euro Superalloys 2010mentioning

confidence: 99%

Lattice Misfit of High Refractory Ruthenium Containing Nickel-Base Superalloys

Neumeier

Ang

Hobbs

et al. 2011

AMR

Self Cite

View full text Add to dashboard Cite

The influence of Ru, Co, Mo and W on the lattice misfit of eight highly alloyed Re containing single crystal nickel-base superalloys was investigated. High resolution X-ray diffraction (XRD) was used to relate the elemental partitioning behavior and the Vegard coefficients of the elements under investigation to the measured lattice parameter of the γ and γ′ phase. The residual chemical segregation and especially the coherency stress-induced tetragonal distortion of the γ matrix lattice in the high Mo containing alloys results in the observation of two different lattice parameters for the γ matrix phase. This leads to three overlapping, but clearly distinguishable {002} X-ray reflections.

show abstract

A1-L1<sub>2</sub> Structures in the Al-Co-Ni-Ti Quaternary Phase System

Cited by 19 publications

References 11 publications

The microstructure and hardness of Ni-Co-Al-Ti-Cr quinary alloys

The microstructure and hardness of Ni-Co-Al-Ti-Cr quinary alloys

Influence of Iridium on the Properties of γ′‐Strengthened Co‐Base Superalloys

Lattice Misfit of High Refractory Ruthenium Containing Nickel-Base Superalloys

Contact Info

Product

Resources

About