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

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Characterization of AM60 Magnesium Alloy Prepared by Rapid Solidification and Plastic Consolidation Technique

Materials Science Forum ◽

10.4028/www.scientific.net/msf.667-669.997 ◽

2010 ◽

Vol 667-669 ◽

pp. 997-1002

Author(s):

Tomasz Tokarski

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Rapid Solidification ◽

Melt Spinning ◽

Bulk Material ◽

Structure Refinement ◽

Hot Extrusion ◽

Solidification Process ◽

Protective Atmosphere ◽

Material Structure

Magnesium and its alloys are attractive candidates for automotive and aerospace applications due to their relatively high strength and low density. However, their low ductility determined by hcp structure of material results in limitation of plastic deformation processing. In order to improve ductility as well as mechanical properties, structure refinement processes can be used. It is well known that effective refining of the material structure can be achieved by increasing the cooling rate during casting procedures, hence rapid solidification process (RSP) has been experimented for the fabrication of magnesium alloys. The present paper reports an experimental investigation on the influence of rapid solidification on the mechanical properties of AM60 magnesium alloy. In order to obtain RS material melt spinning process was applied in protective atmosphere, resulting in formation of RS ribbons. Following consolidation of the RS material is necessary to obtain bulk material with high mechanical properties, as so hot extrusion process was applied. It was noticed that application of plastic consolidation by hot extrusion is the most effective process to achieve full densification of material. For comparison purposes, the conventionally cast and hot extruded AM60 alloy was studied as well. The purpose of the present study was to investigate in detail the effect of rapid solidification and extrusion temperature on the structure and mechanical properties of the materials.

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

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.124-126.1521 ◽

2007 ◽

Vol 124-126 ◽

pp. 1521-1524 ◽

Cited By ~ 1

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).

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Effect of Rapid Solidification on the Structure and Mechanical Properties of AZ91 Magnesium Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.186.120 ◽

2012 ◽

Vol 186 ◽

pp. 120-123 ◽

Cited By ~ 1

Author(s):

Tomasz Tokarski

Keyword(s):

Mechanical Properties ◽

Magnesium Alloy ◽

Rapid Solidification ◽

Melt Spinning ◽

Hot Extrusion ◽

Protective Atmosphere ◽

Material Structure ◽

Dispersion Strengthening ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium

The present paper reports an experimental investigation of rapid solidification (RS) influence on the structure and mechanical properties of commercial AZ91 magnesium alloy. In order to obtain RS material melt spinning process was applied in protective atmosphere, resulting in formation of 50 to 100 μm thickness RS ribbons. Application of plastic consolidation (PC) by hot extrusion to the highly fragmented magnesium strips allowed to obtain high bulk strength material. It was found that yield strength (YS) and ultimate tensile strength (UTS) of RS+PC material with comparison to the cast and extruded samples were increased from 220 MPa to 303 MPa and from 287 MPa to 385 MPa, respectively, while plasticity of the RS material was slightly decreased. It was noticed that the grain size of both materials was at the same level of 2 μm, thus higher mechanical properties of RS material was ascribed to dispersion strengthening caused by the high amount of fine (below 50 nm in diameter) Mg17Al12phases evenly distributed in the material structure.

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

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.765 ◽

2007 ◽

Vol 534-536 ◽

pp. 765-768 ◽

Cited By ~ 1

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.

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Development Of High-Strength Aluminum-Based Alloys By Synthesis Of New Multicomponent Quasicrystals

MRS Proceedings ◽

10.1557/proc-553-495 ◽

1998 ◽

Vol 553 ◽

Cited By ~ 5

Author(s):

A. Inoue ◽

H. M. Kimura

Keyword(s):

Mechanical Properties ◽

Powder Metallurgy ◽

Rapid Solidification ◽

Future Development ◽

High Strength ◽

Supercooled Liquid ◽

Engineering Properties ◽

Atomic Configuration ◽

Lanthanide Metal ◽

Bulk Alloys

AbstractBy the control of composition, clustered atomic configuration and stability of the supercooled liquid in the rapid solidification and powder metallurgy processes, high-strength Al-based bulk alloys containing nanoscale nonperiodic phases were produced in AI-Ln-LTM, AI-ETM-LTM and Al-(V, Cr, Mn)-LTM (Ln=lanthanide metal, LTM=VII and VIII group metals, ETM=IV to VI group metals) alloys containing high Al contents of 92 to 95 at%. The nonperiodic phases are composed of amorphous or icosahedral (I) phase. In particular, the Al-based bulk alloys consisting of nanoscale I particles surrounded by Al phase exhibit much better mechanical properties as compared with commercial Al base alloys. The success of producing the Al-based alloys with good engineering properties by use of I phase is important for future development of I-based alloys as practical materials.

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