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

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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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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Producing Ultrafine Grain Structure in AZ91 Magnesium Alloy Cast by Rapid Solidification

Archives of Metallurgy and Materials ◽

10.2478/amm-2014-0052 ◽

2014 ◽

Vol 59 (1) ◽

pp. 317-321 ◽

Cited By ~ 2

Author(s):

M. Szymanek ◽

B. Augustyn ◽

D. Kapinos ◽

S. Boczkal ◽

J. Nowak

Keyword(s):

Magnesium Alloy ◽

Rapid Solidification ◽

Melt Spinning ◽

Hot Extrusion ◽

Solidification Process ◽

Grain Structure ◽

Ultrafine Grain ◽

Az91 Magnesium Alloy ◽

Az91 Magnesium ◽

Ultrafine Grain Structure

Abstract The paper presents the technological aspect of the process of casting, crushing and plastic consolidation of semi-finished products from magnesium alloy. The aim of this study was to produce by the rapid solidification process a magnesium alloy from the MgAl9Zn1 family in the form of ribbons with ultrafine grain structure. The material cast in the melt spinning device was next crushed and subjected to the operation of cold consolidation and hot extrusion. The paper presents different stages of the process, including initial characterisation of the obtained material.

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Influence of Hot Extrusion on Microstructure and Mechanical Properties of As-Cast AZ91 Magnesium Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.704-705.892 ◽

2011 ◽

Vol 704-705 ◽

pp. 892-896

Author(s):

Bao Hong Zhang ◽

Zhi Min Zhang

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Magnesium Alloy ◽

Yield Strength ◽

Hot Extrusion ◽

Extrusion Ratio ◽

Extrusion Temperature ◽

Az91 Magnesium Alloy ◽

Microstructure And Mechanical Properties ◽

Az91 Magnesium

In order to study the effect of plastic deformation on microstructure and mechanical properties of as-cast AZ91 magnesium alloy, experiments of hot direct extrusion were performed at different extrusion temperatures and different extrusion ratios. The microstructure and mechanical properties of extruded billets and extrudate were measured. Experimental results show that the grain size of as-cast AZ91 magnesium alloy can be dramatically refined by extrusion. Hot extrusion can obviously improve the mechanical properties of as-cast AZ91 magnesium Alloy, comparing with the pre-extruded billet, the tensile strength, yield strength and elongation of extrudate can be improved by at least 69%, 117% and 150% respectively. As the extrusion temperature increases, the tensile strength and yield strength of extrudate will increase. As the extrusion ratio increases, the tensile strength and yield strength of extrudate will increase at first and then fall. At the time of extrusion temperature of 420°C and extrusion ratio of 45, the highest tensile strength of 381Mpa and yield strength of 303MPa can be achieved for the extrudate.

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