Primary dendrite growth of Co3Sn2 intermetallic compound in rapidly solidified ternary Co35Cu35Sn30 alloy

A series of aluminum-lithium or lightweight alloys containing up to 5 wt. % lithium was rapidly solidified from melt by chillblockmelt-spun technique. The resultant ribbons were studied by X-ray diffraction (XRD), scanning electron microscope(SEM) and deferential scanning calorimetry (DSC) techniques. The results showed that the structures of all melt-spunribbons were completely composed of two distinct phasesâ€™ aluminum rich phase and intermetallic compound (IMC) Al9.8-Li1.1phase. It is also found that melting point, solidus and liquidus temperatures of the lightweight alloys are lowered asthe Li content is increased. Additionally, elastic moduli, internal friction, thermal diffusivity and hardness measurements ofmelt-spun ribbons were examined by using dynamic resonance method and Vickers indenter for one applied load of 25grams of force for 5, 20, 40, 60, 80 and 99 seconds. Results interpreted in terms of the phase changes occurring in thealloy system. With the addition of Li, the Al rich phase is finer in grain size, and intermetallic compound is more uniformlydistributed. As a result, Young's modulus and micro-hardness of Lightweight are increased when Li is added into the Alalloy. The aim of the research planned in this work was to design the A1-Li family of alloys contribute to their increasinglybroad application in aeronautics, as an alternative for the aluminum alloys, which have been used so far.

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Multi-scale simulation of the dendrite growth during selective laser melting of rare earth magnesium alloy

Modelling and Simulation in Materials Science and Engineering ◽

10.1088/1361-651x/ac3ca3 ◽

2021 ◽

Vol 30 (1) ◽

pp. 015005

Author(s):

Wenli Wang ◽

Wenqiang Liu ◽

Xin Yang ◽

Rongrong Xu ◽

Qiuyun Dai

Keyword(s):

Selective Laser Melting ◽

Interpolation Method ◽

Primary Dendrite ◽

Concentration Field ◽

Dendrite Growth ◽

Scale Model ◽

Laser Melting ◽

Dendrite Morphology ◽

Multi Scale ◽

Primary Dendrite Arm Spacing

Abstract The solidification microstructure of the alloy fabricated by the selective-laser-melting (SLM) process can significantly impact its mechanical properties. In this study, a multi-scale model which couples the macroscale model for thermal-fluid and microscale cellular automata (CA) was proposed to simulate the complex solidification evolution and the dendrite growth (from planar to cellular to dendritic growth) during the SLM process. The solid–liquid interface of CA was dispersed with the bilinear interpolation method. On that basis, the curvature was accurately determined, and the calculation result was well verified by employing the Kurz–Giovanola–Trivedi analytical solution. The dendrite morphology, solute distribution, and primary dendrite arm spacing during the solidification of the SLM molten pool were quantitatively analyzed with the proposed model, well consistent with the experiment. The distribution of the undercooling field and the concentration field at the tip of dendrites different orientations were analyzed, and the two competing growth mechanisms of converging and diverging growth were revealed. Moreover, the research also indicates that during the growth of dendrites, the result of dendrite competition is determined by the height of the dendrite tip position in the direction of the thermal gradient, while the distribution of the concentration field (symmetrical or asymmetric) at the tip of the dendrite critically impacted the competing growth form of dendrites.

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Microstructures Development in Al-5Fe and Al-5Fe-3Y Alloys Solidified at Different Cooling Rate

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.189-193.2462 ◽

2011 ◽

Vol 189-193 ◽

pp. 2462-2466

Author(s):

Guo Fa Mi ◽

Cui Fen Dong ◽

Chang Yun Li ◽

Hai Yan Wang

Keyword(s):

Rare Earth ◽

Phase Composition ◽

Intermetallic Compound ◽

Cooling Rate ◽

Melt Spinning ◽

Metastable Phase ◽

Vacuum Melting ◽

Suction Casting ◽

Rapidly Solidified

Cast, sub-rapidly solidified and rapidly solidified Al-5Fe alloy and Al-5Fe-3Y alloy were respectively prepared by vacuum melting, suction casting and melt spinning. The effect of increasing cooling rate and adding rare earth Y alloy on microstructures and phase composition were investigated. The results showed that the acicular Al3Fe phase transferred to spherical phase and dispersed secondary precipitations were also found when 3.0 wt% Y was added in the Al-5Fe alloy. Meanwhile, the microstructures were apparently refined by the increasing of cooling rate. The metastable phase A16Fe and intermetallic compound A110Fe2Y phase have been observed in Al-5Fe alloy and Al-5Fe-3Y alloy, respectively.

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Mechanical and Structural Characterization of Rapidly Solidified Al-Fe-Mg Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.231.11 ◽

2015 ◽

Vol 231 ◽

pp. 11-18

Author(s):

Anna Kula ◽

Ludwik Blaz ◽

Piotr Kusper ◽

Makoto Sugamata

Keyword(s):

Mechanical Properties ◽

Intermetallic Compound ◽

Rapid Solidification ◽

Structural Characterization ◽

Hot Extrusion ◽

Mg Alloys ◽

Microstructure Refinement ◽

Series Of Experiments ◽

Rapidly Solidified

Series of experiments on a series of Al-Fe-Mg alloys were performed to determine the effect of rapid solidification (RS) on the material strengthening, which result from the refining of thegrain size and intermetallic compound. Additionally, an enhancement of the material strengthening due to magnesium addition was also observed. Manufacture of RS Al-Fe-Mg alloys combined a spraydeposition of the molten alloy on the rotating water-cooled copper roll and plastic consolidation bymeans of powders pressing and hot extrusion methods. The results suggest that the rapid solidification provides an effective method of microstructure refinement and, in combination with solid solutionhardening due to Mg, leads to significant improvement of mechanical properties of Al-Fe-Mg based alloys.

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Microstructure and mechanical properties of rapidly solidified FeAlCr intermetallic compound

Journal of Applied Research and Technology ◽

10.22201/icat.16656423.2009.7.02.523 ◽

2009 ◽

Vol 7 (02) ◽

Author(s):

R. A. Rodríguez-Díaz ◽

M. Suárez ◽

J. Juárez-Islas ◽

M. G. Garnica-Romo ◽

J. Arenas-Alatorre ◽

...

Keyword(s):

Crystal Structure ◽

Electron Microscopy ◽

Mechanical Properties ◽

Grain Size ◽

Intermetallic Compound ◽

Tensile Tests ◽

Chemical Analyses ◽

Melt Spun ◽

Melt Spun Ribbons ◽

Rapidly Solidified

In this work results regarding microstructural characterization of a melt‐spun intermetallic compound Fe40Al5Cr (% at.) produced by rapid solidification employing the melt spinning technique at three different tangential wheel speeds (12, 16 and 20 ms‐1) are presented. Melt spun ribbons were characterized by optical and scanning electron microscopy (SEM) in order to observe morphology, grain size, ribbon thickness and also fracture surfaces after tensile tests. EDS coupled to SEM was employed to perform punctual and scan line chemical analyses on samples, x‐ray diffraction (XRD) was utilized to identify crystal structure and phases. Transmission electron microscopy (TEM) was employed to confirm crystal structure and also to characterize nanopores formed in the specimens by vacancy clustering. With regard to mechanical properties, micro hardness Vickers measurements as well as tensile tests at room temperature were applied to the rapidly solidified ribbons.The grain size of rapidly solidified Fe40Al5Cr ribbons suffered a drastic reduction as compared with alloys of the same composition produced by conventional melting and casting methods, and in melt‐spun ribbons it decreases as the wheel speed increases. Punctual and line‐scanning chemical analyses revealed that Cr enters in solid solution in FeAl matrix. Hardness measurements revealed a softening in rapidly solidified FeAlCr ribbons as compared with FeAl alloys and tensile test exhibited a (transgranular + intergranular) mode of fracture, reaching up to 3 % of elongation in FeAlCr alloys. The presence of porous (meso and nano) were also characterized.

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Effect of Calcium and Strontium on Microstructure of AZ31 Wrought Magnesium Alloys

Materials Science Forum ◽

10.4028/www.scientific.net/msf.686.30 ◽

2011 ◽

Vol 686 ◽

pp. 30-39

Author(s):

Zhuang Qing Zhu ◽

Fu Sheng Pan ◽

Chong Zhao ◽

Yao Bo Hu

Keyword(s):

Intermetallic Compound ◽

Primary Dendrite ◽

Dendrite Spacing ◽

X Ray Diffraction ◽

Cast State ◽

Secondary Dendrite Arm Spacing ◽

X Ray ◽

Dendrite Arm Spacing ◽

Primary Dendrite Spacing ◽

Ternary Intermetallic Compound

AZ31 wrought alloys at as-cast state with different microcontent calcium and strontium was studied by optical microscopy, X-ray diffraction, scanning electron microscopy and energy dispersive X-ray analysis. The study shows that the primary dendrite spacing and the secondary dendrite arm spacing can be refined significantly by Ca or Sr element. At 0.5wt.% Sr and 1.8wt.% Ca, the best refinement effect is fulfilled, its primary dendrite spacing and secondary dendrite arm spacing decreased from 292μm to 87μm. The Al4Sr intermetallic compound is observed at grain boundaries When Sr was added. The Al4Sr disappears after Ca added, a new ternary intermetallic compound (Mg, Al)2Ca presents. The addition of Sr and Ca can cause microhardness increasing.

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