Microstructure and nanohardness of Ti-48%Al alloy prepared by rapid solidification under different cooling rates

2011 ◽  
Vol 21 ◽  
pp. s328-s332 ◽  
Author(s):  
Hong-wei WANG ◽  
Dong-dong ZHU ◽  
Chun-ming ZOU ◽  
Zun-jie WEI
Keyword(s):  
Rapid Solidification ◽  
Al Alloy ◽  
Cooling Rates

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.

Microstructure evolution and plastic deformation of Ni47Co53 alloy under tension

CrystEngComm ◽  
2022 ◽  
Author(s):  
ruibo ma ◽  
Lili Zhou ◽  
Yong-Chao Liang ◽  
Ze-an Tian ◽  
Yun-Fei Mo ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Plastic Deformation ◽  
Rapid Solidification ◽  
Microstructural Evolution ◽  
Microstructure Evolution ◽  
Cooling Rates ◽  
Solidification Processes ◽  
Molecular Dynamics Methods

To investigate microstructural evolution and plastic deformation under tension conditions, the rapid solidification processes of Ni47Co53 alloy are first simulated by molecular dynamics methods at cooling rates of 1011, 1012...

Microstructure evolution during conventional and rapid solidification of a Ti-50at%Al alloy

1987 ◽  
Vol 21 (10) ◽  
pp. 1341-1346 ◽  
Author(s):  
J.J. Valencia ◽  
C. McCullough ◽  
C.G. Levi ◽  
R. Mehrabian
Keyword(s):  
Rapid Solidification ◽  
Microstructure Evolution ◽  
Al Alloy

Cooling Rates and Fine Microstructures of Rsr and Argon Atomized Superalloy Powders

1981 ◽  
Vol 8 ◽  
Author(s):  
F. Cosandey ◽  
R.D. Kissinger ◽  
J.K. Tien
Keyword(s):  
Particle Size ◽  
Rapid Solidification ◽  
Type Alloy ◽  
Cooling Rates ◽  
Dendrite Arm Spacing ◽  
Void Distribution ◽  
Size Characterization ◽  
Particle Size Characterization

ABSTRACTSuperalloy powders of an IN 792 plus Hf type alloy produced from Rapid Solidification (RSR) and Argon Atomized process (AA) techniques are analyzed and compared according to particle size. Characterization of powders include surface and interior morphology, particle size and void distribution, cooling microstructures, microcrystallinity, microsegretation and especially dendrite arm spacing and cooling rates. It is found that, for the alloy studied, RSR cooling rates are a factor of only two to four greater than those for AA, regardless of particle size.

A STEM Microstructural Analysis of Rapidly Solidified High-Sulfur Austenitic Steel

1980 ◽  
Vol 38 ◽  
pp. 394-395
Author(s):  
Thomas F. Kelly
Keyword(s):  
Rapid Solidification ◽  
Average Particle Size ◽  
Microstructural Analysis ◽  
Scanning Transmission Electron Microscope ◽  
Average Particle ◽  
Cooling Rates ◽  
Scanning Transmission ◽  
High Cooling Rates ◽  
Carpenter Technology Corporation ◽  
Rapidly Solidified

Rapid solidification processing (RSP) has been viewed as a means of obtaining better properties from (crystalline) metal alloys where the improvements are a result of the various effects of high cooling rates (> 105°K/sec) on the “as solidified” structure. Described herein are the results of an investigation into the microstructural and microchemical nature of a rapid solidification processed high sulfur, 303 stainless steel using a dedicated scanning transmission electron microscope (STEM). The RSP material of this study was prepared by forced convective cooling, in helium, of centrifugally atomized metal droplets to achieve cooling rates on the order of 105°K/sec. The resultant powder, of n 50 ym average particle size, was consolidated to a fully dense state. Equivalent conventionally processed 303 SS material was obtained from Carpenter Technology Corporation. The 303 SS material of this investigation was therefore studied in three processed states:the rapidly solidified powder, the rapidly solidified and consolidated bar stock, and the conventionally processed material.

Undercooling of Eutectic Sn-57wt%Bi Alloy

2005 ◽  
Vol 480-481 ◽  
pp. 201-206 ◽  
Author(s):  
Walman Benício de Castro
Keyword(s):  
Growth Rate ◽  
Morphological Change ◽  
Rapid Solidification ◽  
Rapid Solidification Processing ◽  
Metals And Alloys ◽  
Solidification Processing ◽  
Cooling Rates ◽  
Nucleation Sites ◽  
Undercooling Level ◽  
High Cooling Rates

Rapid Solidification Processing (RSP), of metals and alloys, is establish by increasing of the undercooling applying high cooling rates (102 - 106 K/s) or by reduce nucleation sites using low cooling rates (1 K/s). Melt undercooling opens new solidification pathways for new nonequilibrium phases and unusual microstructures. Several techniques have been developed to reduce nucleation sites and produce increased undercooling in metals and alloys including the fluxing technique. The aim of this paper is to study the influence of the undercooling level on microstructures of eutectic Sn-57wt%Bi alloy by using the fluxing technique. A morphological change from eutectic to eutectic plus primary dendrites bSn was observed when the undercooling increase from 10 K to 19 K and a refinement of the primary dendrites bSn was observed when the undercooling increase from 19 K to 29 K. Increasing the undercooling led to a higher growth rate, hence morphological refinement occur.

scholarly journals Nucleation behaviour and microstructure of single Al-Si12 powder particles rapidly solidified in a fast scanning calorimeter

2021 ◽  
Author(s):  
Bin Yang ◽  
Qin Peng ◽  
Benjamin Milkereit ◽  
Armin Springer ◽  
Dongmei Liu ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Rapid Solidification ◽  
Heterogeneous Nucleation ◽  
Cooling Rates ◽  
Solidification Behaviour ◽  
Nucleation Undercooling ◽  
In Situ Investigation ◽  
Solidification Processes ◽  
Powder Particles ◽  
Rapidly Solidified

AbstractThe understanding of rapid solidification behaviour, e.g. the undercooling versus growth velocity relationship, is crucial for tailoring microstructures and properties in metal alloys. In most rapid solidification processes, such as additive manufacturing (AM), in situ investigation of rapid solidification behaviour is missing because of the lack of accurate measurement of the cooling rate and nucleation undercooling. In the present study, rapid solidification of single micro-sized Al-Si12 (mass%) particles of various diameters has been investigated via differential fast scanning calorimetry employing controllable cooling rates from 100 to 90,000 K s−1 relevant for AM. Based on nucleation undercooling and on microstructure analysis of rapidly solidified single powder particles under controlled cooling rates, two different heterogeneous nucleation mechanisms of the primary α-Al phase are proposed. Surface heterogeneous nucleation dominates for particles with diameter smaller than 23 μm. For particles with diameter larger than 23 μm, the nucleation of the primary α-Al phase changes from surface to bulk heterogeneous nucleation with increasing cooling rate. The results indicate that at large undercoolings (> 95 K) and high cooling rates (> 10,000 K s−1), rapid solidification of single particle can yield a microstructure similar to that formed in AM. The present work not only proposes new insight into rapid solidification processes, but also provides a theoretical foundation for further understanding of microstructures and properties in additively manufactured materials.

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