Microstructural Instability and Precipitation Behaviors of Intermetallic Phases in a Nb-Containing CoNi-Based Superalloy

2020 ◽  
Vol 51 (5) ◽  
pp. 2495-2508
Author(s):  
Zhongding Fan ◽  
Xinguang Wang ◽  
Yanhong Yang ◽  
Hao Chen ◽  
Zhigang Yang ◽  
...  
Keyword(s):  
Intermetallic Phases ◽  
Microstructural Instability

Identification by Electron Microdiffraction of Intermetallic Phases in a Duplex Stainless Steel

1990 ◽  
Vol 48 (2) ◽  
pp. 494-495
Author(s):  
A. Redjaïmia ◽  
J.P. Morniroli ◽  
G. Metauer ◽  
M. Gantois
Keyword(s):  
Stainless Steel ◽  
Duplex Stainless Steel ◽  
Convergent Beam Electron Diffraction ◽  
Intermetallic Phases ◽  
Small Particles ◽  
Parallel Beam ◽  
Diffraction Patterns ◽  
Average Size ◽  
Convergent Beam ◽  
Electron Microdiffraction

2D and especially 3D symmetry information required to determine the crystal structure of four intermetallic phases present as small particles (average size in the range 100-500nm) in a Fe.22Cr.5Ni.3Mo.0.03C duplex stainless steel is not present in most Convergent Beam Electron Diffraction (CBED) patterns. Nevertheless it is possible to deduce many crystal features and to identify unambiguously these four phases by means of microdiffraction patterns obtained with a nearly parallel beam focused on a very small area (50-100nm).From examinations of the whole pattern reduced (RS) and full (FS) symmetries the 7 crystal systems and the 11 Laue classes are distinguished without ambiguity (1). By considering the shifts and the periodicity differences between the ZOLZ and FOLZ reflection nets on specific Zone Axis Patterns (ZAP) which depend on the crystal system, the centering type of the cell and the glide planes are simultaneously identified (2). This identification is easily done by comparisons with the corresponding simulated diffraction patterns.

BALL MILLING OF INTERMETALLIC PHASES IN THE Nb-Al SYSTEM

1990 ◽  
Vol 51 (C4) ◽  
pp. C4-169-C4-174 ◽  
Author(s):  
M. OEHRING ◽  
R. BORMANN
Keyword(s):  
Ball Milling ◽  
Intermetallic Phases

scholarly journals Possibilities of predicting undesirable iron intermetallic phases in secondary Al-alloys

2021 ◽  
Vol 55 ◽  
pp. 797-804
Author(s):  
Ivana Švecová ◽  
Eva Tillová ◽  
Lenka Kuchariková ◽  
Vidžaja Knap
Keyword(s):  
Intermetallic Phases ◽  
Al Alloys ◽  
Iron Intermetallic

scholarly journals The Influence of La and Ce on Microstructure and Mechanical Properties of an Al-Si-Cu-Mg-Fe Alloy at High Temperature

Metals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 384
Author(s):  
Andong Du ◽  
Anders E. W. Jarfors ◽  
Jinchuan Zheng ◽  
Kaikun Wang ◽  
Gegang Yu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
High Temperature ◽  
Intermetallic Phases ◽  
High Temperature Strength ◽  
Thermal Expansion Mismatch ◽  
Strengthening Mechanisms ◽  
High Temperature Mechanical Properties ◽  
Minor Contribution ◽  
A Minor

The effect of lanthanum (La)+cerium (Ce) addition on the high-temperature strength of an aluminum (Al)–silicon (Si)–copper (Cu)–magnesium (Mg)–iron (Fe)–manganese (Mn) alloy was investigated. A great number of plate-like intermetallics, Al11(Ce, La)3- and blocky α-Al15(Fe, Mn)3Si2-precipitates, were observed. The results showed that the high-temperature mechanical properties depended strongly on the amount and morphology of the intermetallic phases formed. The precipitated tiny Al11(Ce, La)3 and α-Al15(Fe, Mn)3Si2 both contributed to the high-temperature mechanical properties, especially at 300 °C and 400 °C. The formation of coarse plate-like Al11(Ce, La)3, at the highest (Ce-La) additions, reduced the mechanical properties at (≤300) ℃ and improved the properties at 400 ℃. Analysis of the strengthening mechanisms revealed that the load-bearing mechanism was the main contributing mechanism with no contribution from thermal-expansion mismatch effects. Strain hardening had a minor contribution to the tensile strength at high-temperature.

scholarly journals Modelling of Microstructure Evolution during Laser Processing of Intermetallic Containing Ni-Al Alloys

Metals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1051
Author(s):  
Mohammad Amin Jabbareh ◽  
Hamid Assadi
Keyword(s):  
Additive Manufacturing ◽  
Rapid Solidification ◽  
Microstructure Evolution ◽  
Phase Field ◽  
Laser Processing ◽  
Field Model ◽  
Phase Field Model ◽  
Intermetallic Phases ◽  
Al Alloy ◽  
Kinetic Effects

There is a growing interest in laser melting processes, e.g., for metal additive manufacturing. Modelling and numerical simulation can help to understand and control microstructure evolution in these processes. However, standard methods of microstructure simulation are generally not suited to model the kinetic effects associated with rapid solidification in laser processing, especially for material systems that contain intermetallic phases. In this paper, we present and employ a tailored phase-field model to demonstrate unique features of microstructure evolution in such systems. Initially, the problem of anomalous partitioning during rapid solidification of intermetallics is revisited using the tailored phase-field model, and the model predictions are assessed against the existing experimental data for the B2 phase in the Ni-Al binary system. The model is subsequently combined with a Potts model of grain growth to simulate laser processing of polycrystalline alloys containing intermetallic phases. Examples of simulations are presented for laser processing of a nickel-rich Ni-Al alloy, to demonstrate the application of the method in studying the effect of processing conditions on various microstructural features, such as distribution of intermetallic phases in the melt pool and the heat-affected zone. The computational framework used in this study is envisaged to provide additional insight into the evolution of microstructure in laser processing of industrially relevant materials, e.g., in laser welding or additive manufacturing of Ni-based superalloys.

Microstructural instability of L-PBF Co28Cr6Mo alloy at elevated temperatures

2021 ◽  
pp. 102025
Author(s):  
Michaela Roudnická ◽  
Orsolya Molnárová ◽  
Jan Drahokoupil ◽  
Jiří Kubásek ◽  
Jiří Bigas ◽  
...  
Keyword(s):  
Elevated Temperatures ◽  
Microstructural Instability

The scandium-rich indide Sc50Pt13.47In2.53

2020 ◽  
Vol 75 (6-7) ◽  
pp. 715-720 ◽  
Author(s):  
Nataliya L. Gulay ◽  
Jutta Kösters ◽  
Yaroslav M. Kalychak ◽  
Rainer Pöttgen
Keyword(s):  
Single Crystal ◽  
Intermetallic Phases ◽  
Subsequent Annealing ◽  
Induction Melting ◽  
X Ray

AbstractThe scandium-rich indide Sc50Pt13.47In2.53 was obtained by induction melting of the elements and subsequent annealing. The structure of Sc50Pt13.47In2.53 has been refined from single-crystal X-ray diffractometer data: Fm$\overline{3}$, a = 1774.61(3) pm, wR2 = 0.0443, 1047 F2 values and 35 variables. Sc50Pt13.47In2.53 is isopointal with the intermetallic phases Sc50Co12.5In3.5, Sc50Rh13.3In2.7, Sc50Ir13.6In2.4, Ag7+xMg26−x and Ga4.55Mg21.85Pd6.6 (Pearson code cF264 and Wyckoff sequence ih2fecba). Two of the eight crystallographic sites in the structure show mixed occupancies: M1 (≡Pt20.70In10.30) and M2 (≡Pt30.76In20.24). The structure contains four basic polyhedra: M2@Sc8 cubes, Pt1@Sc10 sphenocorona and slightly distorted M1@Sc12 and In3@Sc12 icosahedra. The polyhedra are condensed via common scandium corners and edges. The various Sc–Sc distances range from 302–334 pm and are indicative of substantial Sc–Sc bonding, stabilizing the Sc50Pt13.47In2.53 structure.

scholarly journals Challenges in the Forging of Steel-Aluminum Bearing Bushings

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 803
Author(s):  
Bernd-Arno Behrens ◽  
Johanna Uhe ◽  
Tom Petersen ◽  
Christian Klose ◽  
Susanne E. Thürer ◽  
...  
Keyword(s):  
Intermetallic Layer ◽  
Dissimilar Materials ◽  
Intermetallic Phases ◽  
Internal Diameter ◽  
External Diameter ◽  
Forming Process ◽  
High Deformation ◽  
Eds Analysis ◽  
Steel Aisi ◽  
Metallurgical Bond

The current study introduces a method for manufacturing steel–aluminum bearing bushings by compound forging. To study the process, cylindrical bimetal workpieces consisting of steel AISI 4820 (1.7147, 20MnCr5) in the internal diameter and aluminum 6082 (3.2315, AlSi1MgMn) in the external diameter were used. The forming of compounds consisting of dissimilar materials is challenging due to their different thermophysical and mechanical properties. The specific heating concept discussed in this article was developed in order to achieve sufficient formability for both materials simultaneously. By means of tailored heating, the bimetal workpieces were successfully formed to a bearing bushing geometry using two different strategies with different heating durations. A metallurgical bond without any forging defects, e.g., gaps and cracks, was observed in areas of high deformation. The steel–aluminum interface was subsequently examined by optical microscopy, scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). It was found that the examined forming process, which utilized steel–aluminum workpieces having no metallurgical bond prior to forming, led to the formation of insular intermetallic phases along the joining zone with a maximum thickness of approximately 5–7 µm. The results of the EDS analysis indicated a prevailing FexAly phase in the resulting intermetallic layer.

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