Rapidly Solidified Microstructures in a Ti-22 Wt% Fe Alloy

1983 ◽  
Vol 28 ◽  
Author(s):  
W. A. Baeslack III ◽  
L. Weeter ◽  
S. Krishnamurthy ◽  
P. Smith ◽  
F. H. Froes
Keyword(s):  
Cooling Rate ◽  
Melt Spinning ◽  
Laser Surface ◽  
Power Relationship ◽  
Dendrite Structure ◽  
Melt Extraction ◽  
Grain Sizes ◽  
Columnar Grains ◽  
General Power ◽  
Rapidly Solidified

ABSTRACTRapidly-solidified microstructures were produced in aTi-22 wt% Fe alloy by laser surface melting, melt extraction, melt spinning and splat cooling. Increased cooling rates during solidification promoted increasingly finer beta grain sizes ranging from approximately 75 microns in a laser melt to 0.5 to 2.0 microns for splats. Beta grain morphologiesw ere generally equiaxed, although epitaxially-nucleated columnar grains were observed at the pool-substrate interface for laser melts. Fitting of the equiaxed beta grain size data to a λ0 = Boε−n0 power relationship for homogenous nucleation and isotropic growth resulted in Bo = 3 × 104 and no = 0.62. The refinement of dendrite structure with increasing cooling rate was also documented for laser melts. Dendrite spacing versus cooling rate data were fitted to a similar general power relationship and resulted in B1 = 45 and n1 = 0.34.

scholarly journals The Development of Rapidly Solidified Magnesium – Copper Ribbons

2016 ◽  
Vol 61 (2) ◽  
pp. 1083-1088
Author(s):  
M. Pastuszak ◽  
G. Cieślak ◽  
A. Dobkowska ◽  
J. Mizera ◽  
K.J. Kurzydłowski
Keyword(s):  
Corrosion Resistance ◽  
Cooling Rate ◽  
Melt Spinning ◽  
Diffraction Method ◽  
Electrode System ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Copper Addition ◽  
Rapidly Solidified ◽  
Thermal Stability Of

Abstract The aim of the present work was to plan and carry out an experiment consisting of amorphization of industrial magnesium alloy WE 43 (Mg - 4 Y - 3 RE - 0.5 Zr) modified by the copper addition. Investigated alloy modified with 20% of copper was rapidly quenched with the use of melt spinning technique. The effects of cooling rate on the structure and properties of the obtained material were extensively analyzed. The structure and phase analysis of samples were examined using X-ray diffraction method (XRD) while the thermal stability of the samples was determined by differential scanning calorimetry (DSC). Microstructure observations were also conducted. The microhardness tests (HV0.02) and corrosion resistance tests were carried out to investigate the properties of the material. Corrosion resistance measurements were held using a typical three-electrode system. As the result of the research, the effect of cooling rate on microstructure and properties of investigated alloy was determined.

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

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.

Structural and Magnetic Transitions in Rapidly Solidified Heusler Alloys Ribbons

2009 ◽  
Vol 150 ◽  
pp. 143-157 ◽  
Author(s):  
Joan Josep Suñol ◽  
J. Saurina ◽  
Rastislav Varga ◽  
B. Hernando ◽  
José Luis Sánchez Llamazares ◽  
...  
Keyword(s):  
Martensitic Transformation ◽  
Transformation Temperature ◽  
Short Range ◽  
Melt Spinning ◽  
Heusler Alloys ◽  
Preferential Orientation ◽  
Magnetic Transitions ◽  
Martensitic Transformation Temperature ◽  
Columnar Grains ◽  
Rapidly Solidified

The most extensively studied Heusler alloys are those based on the Ni-Mn-Ga system. However, to overcome the high cost of Gallium and the usually low martensitic transformation temperature, the search for Ga-free alloys has been recently attempted, particularly, by introducing In, Sn or Sb. In this work, Mn50Ni40In10, Mn50Ni34In16, Ni50Mn36-xIn14+x (x = 0, 0.5, 1, 1.5) and Ni50Mn37Sn13 ribbons has been obtained by melt spinning. We outline their structural and thermomagnetic behavior. Columnar grains and preferential orientation has been obtained. The martensitic, Tm, and the Curie, TC, temperatures of the ribbons are lower than those of the bulk samples with similar compositions. This effect is probably due to the ribbons small and constrained grains. For it, a large under-cooling is necessary for the martensitic transformation. The decrease of TC in the ribbons could be associated with the increased degree of quenched-in short-range disorder around defects.

Microstructures of Rapidly Solidified Aluminum Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
J.W. Zindel ◽  
J.T. Stanley ◽  
R.D. Field ◽  
H.L. Fraser
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Aluminum Alloys ◽  
Melt Spinning ◽  
Metastable Phase ◽  
Laser Surface ◽  
Metastable Phase Diagram ◽  
Transmission Electron ◽  
Ternary Additions ◽  
Rapidly Solidified

ABSTRACTAn investigation was performed to study the origin and stability of microstructures in rapidly solidified aluminum alloys. Al-Ni and Al-Fe base alloys were rapidly solidified by means of laser surface melting and melt spinning techniques. Microstructures were studied using optical and transmission electron microscopy. The effect of microstructure on mechanical properties was also studied using microhardness measurements. The origin of the observed microstructural constituents will be explained in terms of features of the metastable phase diagram. The effect of ternary additions on stability will also be considered.

Preparation of Sm2Fe17 Columnar Grains Ribbons by Rapid Quenching

2014 ◽  
Vol 1004-1005 ◽  
pp. 367-370
Author(s):  
Guo Biao Lin ◽  
Xiang Luo ◽  
Wen Long Bi ◽  
Xiao Qian Bao ◽  
Wei Min Mao
Keyword(s):  
Cooling Rate ◽  
Melt Spinning ◽  
Injection Pressure ◽  
Rapid Quenching ◽  
Vacuum Melting ◽  
Nozzle Size ◽  
Columnar Grains

The ingot of Sm-Fe alloy was prepared by vacuum melting. After a process of coarse crushing, it was made into Sm-Fe ribbons by melt-spinning. By analysis of XRD and SEM, it was confirmed that the ribbons composed of fine Sm2Fe17columnar grains with almost the same orientation can be obtained under the condition of 5~7m/s surface rotating velocity of Cu wheel, suitable nozzle size, injection pressure, temperature and composition of the Sm-Fe melt to regulate cooling rate and crystallization. The achievement of the ribbons lays a foundation for preparing anisotropic Sm2Fe17Nxmagnetic powders by rapid quenching.

Effect of Cooling Rate on Microstructure and Mechanical Property of Fe-6.5wt%Si Alloy

2016 ◽  
Vol 850 ◽  
pp. 571-574
Author(s):  
Jing Ye Jiao ◽  
Qi Zhao Shen ◽  
Ai Chao Cheng ◽  
Ren Fei Guo ◽  
Tie Tao Zhou
Keyword(s):  
Cooling Rate ◽  
Silicon Content ◽  
Melt Spinning ◽  
Laser Surface ◽  
Gas Atomization ◽  
Micro Hardness ◽  
X Ray Diffraction ◽  
X Ray ◽  
Laser Surface Remelting ◽  
Microstructure And Mechanical Property

Due to its high silicon content, Fe-6.5wt%Si alloy has low iron loss and its magnetostriction is almost zero. And therefore Fe-6.5wt%Si alloy has good development prospect. However it has poor ambient temperature ductility and its cold rolling is very difficult. It’s important to study the effect of cooling rate on the microstructure and mechanical properties of Fe-6.5wt%Si alloy. In the present study the master alloy was melted and cooled through normalization, gas atomization, laser surface remelting and melt spinning. The microstructure, micro-hardness and X-ray diffraction were analyzed. The evolution of the microstructure at different cooling rate was summarized. The results indicated that under high cooling rate, the grain was obviously refined, and the microhardness decreased, but the change of phase was not obvious.

Microstructures of Rapidly Solidified Titanium-Eutectoid Former Alloys

1983 ◽  
Vol 28 ◽  
Author(s):  
S. Krishnamurthy ◽  
R. G. Vogt ◽  
D. Eylon ◽  
F. H. Froes
Keyword(s):  
Optical Microscopy ◽  
Rapid Solidification ◽  
Melt Spinning ◽  
Binary Alloys ◽  
Microstructural Characterization ◽  
Pendant Drop ◽  
Melt Extraction ◽  
Sem And Tem ◽  
Rapidly Solidified

ABSTRACTTitanium-base binary alloys containing eutectoid forming additions such as Fe, Si, W, and Cr were rapidly solidified by pendant drop melt extraction, melt spinning, and “hammer and anvil” techniques. The materials obtained were fibers, ribbons, and splats, respectively. The microstructures of these rapidly solidified materials were analyzed by optical microscopy, SEM, and TEM. The fibers showed fine microstructures near the quenched side, but less homogeneous and coarser microstructures were observed away from this side. Similar variations were observed between the edge and the center of splats. The results of this microstructural characterization are discussed, and a comparison made between microstructures obtained by the different rapid solidification methods used.

Suppression of γ’ Precipitation in a Laser-Melted Nickel-Base Alloy

1977 ◽  
Vol 35 ◽  
pp. 270-271
Author(s):  
J. M. Walsh ◽  
J. C. Whittles ◽  
B. H. Kear ◽  
E. M. Breinan
Keyword(s):  
Cooling Rate ◽  
Base Alloy ◽  
Material Surface ◽  
Intimate Contact ◽  
Absorbed Power ◽  
Perfect Contact ◽  
Nickel Base ◽  
Rapidly Solidified ◽  
Limiting Case ◽  
The Heat Transfer Coefficient

Conventionally cast γ’ precipitation hardened nickel-base superalloys possess well-defined dendritic structures and normally exhibit pronounced segregation. Splat quenched, or rapidly solidified alloys, on the other hand, show little or no evidence for phase decomposition and markedly reduced segregation. In what follows, it is shown that comparable results have been obtained in superalloys processed by the LASERGLAZE™ method.In laser glazing, a sharply focused laser beam is traversed across the material surface at a rate that induces surface localized melting, while avoiding significant surface vaporization. Under these conditions, computations of the average cooling rate can be made with confidence, since intimate contact between the melt and the self-substrate ensures that the heat transfer coefficient is reproducibly constant (h=∞ for perfect contact) in contrast to the variable h characteristic of splat quenching. Results of such computations for pure nickel are presented in Fig. 1, which shows that there is a maximum cooling rate for a given absorbed power density, corresponding to the limiting case in which melt depth approaches zero.

Microstructures of Laser Processed Fe-Cr Surface Alloys

1981 ◽  
Vol 39 ◽  
pp. 328-329
Author(s):  
P. A. Molian ◽  
K. H. Khan ◽  
W. E. Wood
Keyword(s):  
Cooling Rate ◽  
Pure Iron ◽  
Continuous Wave ◽  
Laser Surface ◽  
Material Surface ◽  
Constitution Diagram ◽  
Incident Power ◽  
Surface Alloying ◽  
Laser Surface Alloying ◽  
Spot Diameter

In recent years, the effects of chromium on the transformation characteristics of pure iron and the structures produced thereby have been extensively studied as a function of cooling rate. In this paper, we present TEM observations made on specimens of Fe-10% Cr and Fe-20% Cr alloys produced through laser surface alloying process with an estimated cooling rate of 8.8 x 104°C/sec. These two chromium levels were selected in order to study their phase transformation characteristics which are dissimilar in the two cases as predicted by the constitution diagram. Pure iron (C<0.01%, Si<0.01%, Mn<0.01%, S=0.003%, P=0.008%) was electrodeposited with chromium to the thicknesses of 40 and 70μm and then vacuum degassed at 400°F to remove the hydrogen formed during electroplating. Laser surface alloying of chromium into the iron substrate was then performed employing a continuous wave CO2 laser operated at an incident power of 1200 watts. The laser beam, defocussed to a spot diameter of 0.25mm, scanned the material surface at a rate of 30mm/sec, (70 ipm).

Sign in / Sign up

Export Citation Format

Share Document