A Comparative Study of Mechanical Property in Al-8Fe-2Mo-2V-1Zr Bulk Alloys Fabricated from an Atomized Powder and a Melt Spun Ribbon

2007 ◽  
Vol 534-536 ◽  
pp. 765-768 ◽  
Author(s):  
Taek Kyun Jung ◽  
T.J. Sung ◽  
Mok Soon Kim ◽  
Won Yong Kim
Keyword(s):  
Yield Strength ◽  
Melt Spinning ◽  
Elevated Temperatures ◽  
Maximum Yield ◽  
Hot Extrusion ◽  
Particle Sizes ◽  
Gas Atomization ◽  
Melt Spun ◽  
Average Size ◽  
Equiaxed Grains

Al-8Fe-2Mo-2V-1Zr alloy powders were prepared by gas atomization and melt spinning method. In melt spinning technique, melt spun ribbons were pulverized by a speed rotor mill to make a powder shape. In order to produce a bulk form, powders were canned and hot extruded in the extrusion ratio of 25 to 1 at 693K. For the gas atomization and hot extrusion processed bulk material, equiaxed grains with the average size of 400 nm and finely distributed dispersoids with their particle sizes ranging from 50nm to 200nm were observed to display a characteristic nano-structured feature over the entire region. For the melt spun and hot extrusion processed alloy, a refined microstructural feature consisting of equiaxed grains with the average size of 200 nm and fine dispersoids with their particle sizes under 50 nm appeared to exhibit a difference in microstructure. Yield strength of the latter alloy was higher than that for the former alloy up to elevated temperatures. The maximum yield strength was measured to about 800 MPa at room temperature for the latter alloy.

Microstructure and Compression Properties of Al-8Fe-2Mo-2V-1Zr Alloys Produced by Extrusion of Melt-Spun Powders

2007 ◽  
Vol 124-126 ◽  
pp. 1521-1524 ◽  
Author(s):  
Taek Kyun Jung ◽  
T.J. Sung ◽  
Mok Soon Kim ◽  
W.Y. Kim
Keyword(s):  
Melt Spinning ◽  
Elevated Temperatures ◽  
Hot Extrusion ◽  
High Yield ◽  
Compression Properties ◽  
Nano Crystalline ◽  
Average Grain Size ◽  
Multi Phase ◽  
Equiaxed Grains ◽  
Bulk Alloys

Bulk Al-8Fe-2Mo-2V-1Zr (wt.%) alloys were produced by melt spinning which can give rise to develope a nano crystalline structure in terms of rapid cooling and subsequent hot extrusion. The bulk alloys exhibited multi-phase microstructures consisting of ultra fine equiaxed grains with the average grain size of 100nm and a fine intermetallic Al-Fe, Al-V and Al-Zr based phase having less than 50nm in particle size. From compression test, it was revealed that the bulk alloys have very high yield strength at both room temperature (942MPa) and elevated temperatures (651MPa at 473K, 500MPa at 573K, respectively).

Fabrication and Properties of High Strength Al-8Fe-2Mo-2V-1Zr Alloy Produced by Melt Spinning Techniques

2006 ◽  
Vol 510-511 ◽  
pp. 854-857 ◽  
Author(s):  
Taek Kyun Jung ◽  
Dong Suk Lee ◽  
Mok Soon Kim ◽  
Won Yong Kim
Keyword(s):  
Particle Size ◽  
Yield Strength ◽  
Melt Spinning ◽  
Room Temperature ◽  
Intermetallic Phase ◽  
Hot Extrusion ◽  
High Strength ◽  
Extrusion Temperature ◽  
Grain Structure ◽  
Melt Spun

High strength Al-8Fe-2Mo-2V-1Zr (wt.%) alloys fabricated by a melt spinning and a hot extrusion process were produced to correlate the microstructure and mechanical property. Melt spun ribbon prepared by single roll melt spinner showed a cellular structure with an average size of 10nm and Al-Fe based intermetallic dispersoid of less than 10nm in particle size. The melt spun ribbon obtained was then pulverized to make a powder shape followed by hot extrusion at 648K, 673K, 723K and 773K in extrusion ratio of 5 to 1, respectively. Equiaxed grain structure containing Al-Fe based intermetallic phase was observed in all extruded specimens. According to increasing extrusion temperature, the grain size increased and particle size of intermetallic dispersoid. The lattice parameter increased from 0.4051nm to 0.4059 nm with increasing extrusion temperature from 648K to 773K, those values were larger than that obtained in pure Al (0.4049nm). Yield strength of the specimen extruded at 648K measured to 956MPa at room temperature, 501MPa at 573K and 83MPa at 773K, respectively. With increasing extrusion temperature yield strength decreased significantly at room temperature and even in the intermediate temperature range, while no noticeable difference in yield strength was observed at 773K.

Process Dependence of Microstructure and Mechanical Properties for Al-Fe Based Bulk Alloys

2015 ◽  
Vol 736 ◽  
pp. 24-29
Author(s):  
Taek Kyun Jung ◽  
Ho Joon Choi ◽  
Young Chul Shin ◽  
Hyo Soo Lee ◽  
Hyouk Chon Kwon
Keyword(s):  
Mechanical Properties ◽  
Rapid Solidification ◽  
Melt Spinning ◽  
Hot Extrusion ◽  
Spray Forming ◽  
A Value ◽  
Microstructure And Mechanical Properties ◽  
Melt Spun ◽  
Equiaxed Grains ◽  
Bulk Alloys

In this work, a comparative study of the microstructure and mechanical properties of Al-8Fe based bulk alloys fabricated by three different rapid solidification methods and subsequent hot extrusion was carried out. Spray forming, gas atomization, and melt spinning methods were used as techniques for rapid solidification having various cooling rates. Equiaxed grains containing Al-Fe, Al-Fe-(Mo, V), and Al-Zr phase particles were characterized. The yield strength of the melt spun and extruded specimen was estimated to approximately 800 MPa at room temperature, a value which is roughly 1.5 times higher than that obtained for the atomized and extruded specimen and roughly 2.5 times higher than for the spray formed and extruded specimen. The higher strength of the melt spun and extruded specimen originated from a finer microstructure compared to the atomized and extruded specimen and the spray formed and extruded specimen.

scholarly journals Microstructure Development and Properties of the Two-Component Melt-Spun Ni55Fe20Cu5P10B10 Alloy at Elevated Temperatures

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1741
Author(s):  
Krzysztof Ziewiec ◽  
Mirosława Wojciechowska ◽  
Irena Jankowska-Sumara ◽  
Aneta Ziewiec ◽  
Sławomir Kąc
Keyword(s):  
High Temperature ◽  
Melt Spinning ◽  
Elevated Temperatures ◽  
Amorphous State ◽  
Nominal Composition ◽  
Composite Alloy ◽  
X Ray Diffraction ◽  
Heating Rates ◽  
Two Component ◽  
Melt Spun

The aim of this work was to investigate the features of microstructure, phase composition, mechanical properties, and thermal stability of the two-component melt-spun Ni55Fe20Cu5P10B10 alloy. The development of the microstructure after heating to elevated temperatures was studied using scanning electron microscope and in situ high temperature X-ray diffraction. The high-temperature behavior of the two-component melt-spun Ni55Fe20Cu5P10B10 alloy and Ni40Fe40B20, Ni70Cu10P20, and Ni55Fe20Cu5P10B10 alloys melt-spun from single-chamber crucible was investigated using differential scanning calorymetry at different heating rates and by dynamic mechanical thermal analysis. The results show that band-like microstructure of the composite alloy is stable even at 800 K, although coarsening of bands forming the microstructure of the ribbons is observed above 550 K. Plastic deformation is observed in the composite previously heated to temperatures of 600–650 K. The properties of the composite alloy are generally different than the properties obtained for the melt-spun alloy of the same average nominal composition produced traditionally. Additionally, the mechanical and the thermal properties in this composite are inherited from the amorphous state of alloys that are precursors for two-component melt spinning (TCMS) processing.

Enhancement of microstructure uniformity and grain refining efficiency of Al-5Ti-1B alloy via powder extrusion

2020 ◽  
Vol 117 (6) ◽  
pp. 621
Author(s):  
Shuncheng Wang ◽  
Huilan Huang ◽  
Zhibo Zhang ◽  
Kaihong Zheng
Keyword(s):  
Electron Probe ◽  
Hot Extrusion ◽  
Average Diameter ◽  
Rolling Process ◽  
Extrusion Process ◽  
Gas Atomization ◽  
Grain Refining ◽  
X Ray ◽  
Refining Efficiency ◽  
Equiaxed Grains

Microstructure uniformity and grain refining efficiency of Al-5Ti-1B alloy rod prepared by powder extruded process and continuous casting and rolling process are investigated in detail by X ray diffractometer, scanning electron microscope and electron probe. It is found that TiB2 and TiAl3 particles are uniformly distributed in the powder extruded Al-5Ti-1B alloy via gas atomization and hot extrusion process. The samples with 0.2% powder extruded Al-5Ti-1B alloy rod holding for 2 min consist of equiaxed grains with an average diameter of 183 µm. Even the holding time extended to 180 min, the average diameter is still stable (229 µm). Al-5Ti-1B alloy rod prepared by the powder extruded process presents better grain refinement and stronger resistance to grain coarsening.

Spherulite Structures in a Melt Spun Fe-Ni Austenitic Steel

1985 ◽  
Vol 43 ◽  
pp. 52-53
Author(s):  
G. M. Michal ◽  
T. K. Glasgow ◽  
T. J. Moore
Keyword(s):  
Austenitic Steel ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Large Range ◽  
Amorphous Structure ◽  
Nucleation And Growth ◽  
Ni Alloys ◽  
Melt Spun ◽  
Crystal Fibers ◽  
Rapidly Solidified

Large additions of B to Fe-Ni alloys can lead to the formation of an amorphous structure, if the alloy is rapidly cooled from the liquid state to room temperature. Isothermal aging of such structures at elevated temperatures causes crystallization to occur. Commonly such crystallization pro ceeds by the nucleation and growth of spherulites which are spherical crystalline bodies of radiating crystal fibers. Spherulite features were found in the present study in a rapidly solidified alloy that was fully crysstalline as-cast. This alloy was part of a program to develop an austenitic steel for elevated temperature applications by strengthening it with TiB2. The alloy contained a relatively large percentage of B, not to induce an amorphous structure, but only as a consequence of trying to obtain a large volume fracture of TiB2 in the completely processed alloy. The observation of spherulitic features in this alloy is described herein. Utilization of the large range of useful magnifications obtainable in a modern TEM, when a suitably thinned foil is available, was a key element in this analysis.

A TEM study of the effect of oxygen on nanocavity formation and precipitation in rapid - solidified Fe-16Ni-9Cr stainless steels

1994 ◽  
Vol 52 ◽  
pp. 700-701
Author(s):  
S. Wisutmethangoon ◽  
T. F. Kelly ◽  
J.E. Flinn
Keyword(s):  
Stainless Steels ◽  
High Mobility ◽  
Hot Extrusion ◽  
Extrusion Ratio ◽  
Gas Atomization ◽  
Cavity Formation ◽  
Nucleation Sites ◽  
Heat Treated ◽  
Different Types ◽  
Effect Of Oxygen

Vacancies are introduced into the crystal phase during quenching of rapid solidified materials. Cavity formation occurs because of the coalescence of the vacancies into a cluster. However, because of the high mobility of vacancies at high temperature, most of them will diffuse back into the liquid phase, and some will be lost to defects such as dislocations. Oxygen is known to stabilize cavities by decreasing the surface energy through a chemisorption process. These stabilized cavities, furthermore, act as effective nucleation sites for precipitates to form during aging. Four different types of powders with different oxygen contents were prepared by gas atomization processing. The atomized powders were then consolidated by hot extrusion at 900 °C with an extrusion ratio 10,5:1. After consolidation, specimens were heat treated at 1000 °C for 1 hr followed by water quenching. Finally, the specimens were aged at 600 °C for about 800 hrs. TEM samples were prepared from the gripends of tensile specimens of both unaged and aged alloys.

Rapidly Solidified Melt-spun Bi-Sn Ribbons: Surface Composition Issues

2016 ◽  
pp. 3287-3297
Author(s):  
Tarek El Ashram ◽  
Ana P. Carapeto ◽  
Ana M. Botelho do Rego
Keyword(s):  
Chemical Composition ◽  
Optical Microscopy ◽  
Melt Spinning ◽  
Surface Composition ◽  
Electrochemical Process ◽  
Melt Spun ◽  
Bismuth Alloy ◽  
The One ◽  
Rapidly Solidified ◽  
Melt Spinning Technique

Tin-bismuth alloy ribbons were produced using melt-spinning technique. The two main surfaces (in contact with the rotating wheel and exposed to the air) were characterized with Optical Microscopy and AFM, revealing that the surface exposed to the air is duller (due to a long-range heterogeneity) than the opposite surface. Also the XPS chemical composition revealed many differences between them both on the corrosion extension and on the total relative amounts of tin and bismuth. For instance, for the specific case of an alloy with a composition Bi-4 wt % Sn, the XPS atomic ratios Sn/Bi are 1.1 and 3.7 for the surface in contact with the rotating wheel and for the one exposed to air, respectively, showing, additionally, that a large segregation of tin at the surface exists (nominal ratio should be 0.073). This segregation was interpreted as the result of the electrochemical process yielding the corrosion products.

UNS T20819

Alloy Digest ◽  
1989 ◽  
Vol 38 (2) ◽  
Keyword(s):  
Elevated Temperatures ◽  
Hot Extrusion ◽  
Heat Treating ◽  
High Toughness ◽  
Extrusion Dies ◽  
Extrusion Die ◽  
Steel Mills ◽  
Temperature Performance ◽  
Heat Checking ◽  
Resistance To Heat

Abstract UNS T20819 is a hot-work tool and die steel that is characterized by excellent resistance to shock and abrasion at elevated temperatures. This steel provides relatively high toughness and outstanding resistance to heat checking and softening at elevated temperatures. Among its many applications are hot-punch tools, forging dies and inserts, brass extrusion dies, permanent molds for brass casting and hot-extrusion die inserts for steel. This datasheet provides information on composition, hardness, and tensile properties as well as fracture toughness. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-496. Producer or source: Tool steel mills.

Microstructural Studies of NiCoMnIn Magnetic Shape Memory Ribbons

2013 ◽  
Vol 738-739 ◽  
pp. 436-440 ◽  
Author(s):  
Krystian Prusik ◽  
Katarzyna Bałdys ◽  
Danuta Stróż ◽  
Tomasz Goryczka ◽  
Józef Lelątko
Keyword(s):  
Melt Spinning ◽  
Room Temperature ◽  
Parent Phase ◽  
Magnetic Shape Memory ◽  
Melt Spun ◽  
Columnar Grains ◽  
Ebsd Technique ◽  
Microstructural Studies ◽  
Melt Spinning Technique ◽  
Scanning Electron

In present paper two ribbons of the Ni44Co6Mn36In14 (at.%) were prepared under different melt-spinning technique conditions. Microstructure of the ribbons was studied by scanning electron microscopy (SEM). Depending on the liquid ejection overpressure two types of ribbons microstructures were observed. Ribbon T1 for which ejection overpressure was 1.5 bar showed typical melt-spun ribbon microstructure consisting of a top layer of small equi-axial grains and columnar grains below. For T2 ribbon (ejection overpressure 0.2 bar) only a small fraction of the columnar grains were observed. Structure analysis of the ribbons performed by XRD showed that at room temperature both ribbons have B2 parent phase superstructure. No gamma phase precipitates were observed. In order to determine the orientation of the grains the EBSD technique was applied.

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