Semisolid Processing of Magnesium Alloys: Progress and Limitations

2019 ◽  
Vol 285 ◽  
pp. 489-494 ◽  
Author(s):  
Frank Czerwinski
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Tool Life ◽  
Industrial Applications ◽  
Semisolid Processing ◽  
Microstructural Characteristics ◽  
High Affinity ◽  
Reduced Temperature

An application of semisolid processing to magnesium alloys is described, emphasizing both the fundamental aspects and up-to-date successful industrial applications. The key advantages of the semisolid route are discussed, including longer tool life, tighter dimensional tolerances and better process consistency. The particular attention is paid to reduced temperature of semisolid processing, providing common benefits for magnesium alloys due to their high affinity to oxygen, requiring an expensive protection and leading otherwise to ignition and burning. Major microstructural factors controlling properties of magnesium alloys after semisolid processing are considered. It is concluded that although the reduced temperature results in higher part integrity, it does not create beneficial microstructural characteristics converting to substantially improved mechanical properties.

Semisolid Processing of Magnesium Alloys: Microstructure - Property Relationship

2014 ◽  
Vol 217-218 ◽  
pp. 3-7 ◽  
Author(s):  
Frank Czerwiński
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Applied Research ◽  
Special Importance ◽  
Semisolid Processing ◽  
Microstructural Characteristics ◽  
High Affinity ◽  
Property Relationship ◽  
Research Activities ◽  
Reduced Temperature

An application of semisolid processing to magnesium alloys is discussed emphasizing both the fundamental and applied research activities aimed at better understanding the microstructure-property relationship. The reduced temperature of semisolid processing, providing common benefits of longer tool life, tighter dimensional tolerances and better process consistency is of special importance for magnesium alloys due to their high affinity to oxygen, requiring an expensive protection and leading otherwise to ignition and burning. However, the reduced temperature resulting in higher part integrity does not create beneficial microstructural characteristics converting to substantially improved mechanical properties. Major microstructural factors controlling properties of magnesium alloys after semisolid processing are discussed.

scholarly journals Friction Stir Spot Welding: A Review on Joint Macro- and Microstructure, Property, and Process Modelling

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
X. W. Yang ◽  
T. Fu ◽  
W. Y. Li
Keyword(s):  
Mechanical Properties ◽  
Friction Stir Welding ◽  
Numerical Simulations ◽  
Resistance Spot Welding ◽  
Spot Welding ◽  
Single Point ◽  
Industrial Applications ◽  
Friction Stir Spot Welding ◽  
Microstructural Characteristics ◽  
Friction Stir

Friction stir spot welding (FSSW) is a very useful variant of the conventional friction stir welding (FSW), which shows great potential to be a replacement of single-point joining processes like resistance spot welding and riveting. There have been many reports and some industrial applications about FSSW. Based on the open literatures, the process features and variants, macro- and microstructural characteristics, and mechanical properties of the resultant joints and numerical simulations of the FSSW process were summarized. In addition, some applications of FSSW in aerospace, aviation, and automobile industries were also reviewed. Finally, the current problems and issues that existed in FSSW were indicated.

scholarly journals Analysis of Weak Zones in Friction Stir Welded Magnesium Alloys from the Viewpoint of Local Texture: A Short Review

Metals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 970 ◽  
Author(s):  
Dejia Liu ◽  
Yanchuan Tang ◽  
Mingxue Shen ◽  
Yong Hu ◽  
Longzhi Zhao
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Electron Backscatter Diffraction ◽  
Short Review ◽  
Industrial Applications ◽  
Mg Alloys ◽  
Butt Welding ◽  
Friction Stir ◽  
Future Challenges ◽  
Weak Zones

Friction stir welding (FSW) is a promising approach for the joining of magnesium alloys. Although many Mg alloys have been successfully joined by FSW, it is far from industrial applications due to the texture variation and low mechanical properties. This short review deals with the fundamental understanding of weak zones from the viewpoint of texture analysis in FSW Mg alloys, especially for butt welding. Firstly, a brief review of the microstructure and mechanical properties of FSW Mg alloys is presented. Secondly, microstructure and texture evolutions in weak zones are analyzed and discussed based on electron backscatter diffraction data and Schmid factors. Then, how to change the texture and strengthen the weak zones is also presented. Finally, the review concludes with some future challenges and research directions related to the texture in FSW Mg alloys. The purpose of the paper is to provide a basic understanding on the location of weak zones as well as the weak factors related to texture to improve the mechanical properties and promote the industrial applications of FSW Mg alloys.

Semi-Solid Moulding of AZ91D Magnesium Alloy

2016 ◽  
Vol 850 ◽  
pp. 790-801
Author(s):  
Hong Xu ◽  
Xin Zhang ◽  
Chang Shun Wang ◽  
Jin Chuan Hu ◽  
Cheng Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solid State ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Metal Forming ◽  
Forming Process ◽  
Microstructural Characteristics ◽  
Az91d Magnesium Alloy ◽  
Key Points ◽  
Semi Solid

AZ91D magnesium alloy is one of the most widely used magnesium alloys in the production of metal forming, which use the characteristics from liquid state to solid state of metal to form. The present status of the research and application of the semi-solid forming for AZ91D magnesium alloys at present was reviewed in this paper, including the microstructural characteristics, the thixotropic and rheological behavior, the forming process of semi-solid for AZ91D magnesium alloys and the mechanical properties of the parts made of semi-solid magnesium alloys. The developing prospects and the key points of the semi-solid forming for AZ91D magnesium alloys were forecasted, and the industrial application of the alloy were also discussed.

scholarly journals Substitution of Rare Earth Elements in Hot Rolled Magnesium Alloys with Improved Mechanical Properties

2016 ◽  
Vol 854 ◽  
pp. 57-64 ◽  
Author(s):  
Kristina Neh ◽  
Madlen Ullmann ◽  
Rudolf Kawalla
Keyword(s):  
Mechanical Properties ◽  
Rare Earth ◽  
Rare Earth Elements ◽  
Magnesium Alloys ◽  
Elevated Temperatures ◽  
Industrial Applications ◽  
Production Costs ◽  
Final Thickness ◽  
Different Temperatures ◽  
Hot Rolled

Magnesium alloys containing rare earth elements offer excellent strength at room temperature as well as at elevated temperatures and are distinguished by a high ignition-resistance. However, with regard to cost efficiency and the conversation of resources, these alloys are not suitable for commercial industrial applications. Therefore, the research project SubSEEMag at the Institute of Metal Forming/Technische Universität Bergakademie Freiberg focusses on the development of alternative alloy compositions, which meet the requirements on materials properties of magnesium alloys for industrial applications and production costs. Several magnesium alloys containing zinc, aluminum, manganese and calcium were poured in cylindrical molds at the Helmholtz-Zentrum Geesthacht. The characterization of the as-cast condition was carried out by light and scanning electron microscopy. Phase compositions were determined using EDX analysis. The Mg alloys were homogenized at different temperatures. Afterwards, hot rolling to a final thickness of 2.7 mm was conducted. The influence of temperature and time of the annealing on the microstructure and the mechanical properties of the hot rolled condition have been investigated. The results were discussed in comparison to commercial available Mg-RE alloys.

Enhanced mechanical properties of as-cast Mg-Al-Ca magnesium alloys by friction stir processing

2021 ◽  
Vol 296 ◽  
pp. 129880
Author(s):  
Zahra Nasiri ◽  
Mahmoud Sarkari Khorrami ◽  
Hamed Mirzadeh ◽  
Massoud Emamy
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Friction Stir Processing ◽  
Friction Stir

The influence of gadolinium on Al–Ti–C master alloy and its refining effect on AZ31 magnesium alloy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Wenxue Fan ◽  
Hai Hao
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Magnesium Alloys ◽  
Master Alloy ◽  
Cast Alloy ◽  
Az31 Magnesium Alloy ◽  
Synthesis Mechanism ◽  
Refining Effect ◽  
Master Alloys

Abstract Grain refinement has a significant influence on the improvement of mechanical properties of magnesium alloys. In this study, a series of Al–Ti–C-xGd (x = 0, 1, 2, 3) master alloys as grain refiners were prepared by self-propagating high-temperature synthesis. The synthesis mechanism of the Al–Ti–C-xGd master alloy was analyzed. The effects of Al–Ti–C-xGd master alloys on the grain refinement and mechanical properties of AZ31 (Mg-3Al-1Zn-0.4Mn) magnesium alloys were investigated. The results show that the microstructure of the Al–Ti–C-xGd alloy contains α-Al, TiAl3, TiC and the core–shell structure TiAl3/Ti2Al20Gd. The refining effect of the prepared Al–Ti–C–Gd master alloy is obviously better than that of Al–Ti–C master alloy. The grain size of AZ31 magnesium alloy was reduced from 323 μm to 72 μm when adding 1 wt.% Al–Ti–C-2Gd master alloy. In the same condition, the ultimate tensile strength and elongation of as-cast alloy were increased from 130 MPa, 7.9% to 207 MPa, 16.6% respectively.

scholarly journals Effects of a Twin-Screw Extruder Equipped with a Molten Resin Reservoir on the Mechanical Properties and Microstructure of Recycled Waste Plastic Polyethylene Pellet Moldings

Polymers ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 1058
Author(s):  
Hikaru Okubo ◽  
Haruka Kaneyasu ◽  
Tetsuya Kimura ◽  
Patchiya Phanthong ◽  
Shigeru Yao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Performance ◽  
Value Added ◽  
Industrial Applications ◽  
Twin Screw Extruder ◽  
Screw Extruder ◽  
Polymer Properties ◽  
Wide Range ◽  
Twin Screw ◽  
Recycled Plastics

Each year, increasing amounts of plastic waste are generated, causing environmental pollution and resource loss. Recycling is a solution, but recycled plastics often have inferior mechanical properties to virgin plastics. However, studies have shown that holding polymers in the melt state before extrusion can restore the mechanical properties; thus, we propose a twin-screw extruder with a molten resin reservoir (MSR), a cavity between the screw zone and twin-screw extruder discharge, which retains molten polymer after mixing in the twin-screw zone, thus influencing the polymer properties. Re-extruded recycled polyethylene (RPE) pellets were produced, and the tensile properties and microstructure of virgin polyethylene (PE), unextruded RPE, and re-extruded RPE moldings prepared with and without the MSR were evaluated. Crucially, the elongation at break of the MSR-extruded RPE molding was seven times higher than that of the original RPE molding, and the Young’s modulus of the MSR-extruded RPE molding was comparable to that of the virgin PE molding. Both the MSR-extruded RPE and virgin PE moldings contained similar striped lamellae. Thus, MSR re-extrusion improved the mechanical performance of recycled polymers by optimizing the microstructure. The use of MSRs will facilitate the reuse of waste plastics as value-added materials having a wide range of industrial applications.

scholarly journals Evaluation of the influence of design in the mechanical properties of honeycomb cores used in composite panels

2021 ◽  
pp. 146442072098519
Author(s):  
A Miranda ◽  
M Leite ◽  
L Reis ◽  
E Copin ◽  
MF Vaz ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Polylactic Acid ◽  
Failure Modes ◽  
Industrial Applications ◽  
Sandwich Composite ◽  
Composite Panels ◽  
Distribution Analysis ◽  
Absorbed Energy ◽  
Fused Filament Fabrication ◽  
Subtractive Manufacturing

The aerospace, automotive, and marine industries are heavily reliant on sandwich panels with cellular material cores. Although honeycombs with hexagonal cells are the most commonly used geometries as cores, recently there have been new alternatives in the design of lightweight structures. The present work aims to evaluate the mechanical properties of metallic and polymeric honeycomb structures, with configurations recently proposed and different in-plane orientations, produced by additive and subtractive manufacturing processes. Structures with configurations such as regular hexagonal honeycomb (Hr), lotus (Lt), and hexagonal honeycomb with Plateau borders (Pt), with 0°, 45°, and 90° orientations were analyzed. To evaluate its properties, three-point bending tests were performed, both experimentally and by numerical modeling, by means of the finite element method. Honeycombs of two aluminum alloys and polylactic acid were fabricated. The structures produced in aluminum were obtained either by selective laser melting technology or by machining, while polylactic acid structures were obtained by material extrusion using fused filament fabrication. From the stress distribution analysis and the load–displacement curves, it was possible to evaluate the strength, stiffness, and absorbed energy of the structures. Failure modes were also analyzed for polylactic acid honeycombs. In general, a strong correlation was observed between numerical and experimental results. The results show that the stiffness and absorbed energy increase in the order, Hr, Pt, Lt, and with the orientation through the sequence, 45°, 90°, 0°. Thus, Lt structures with 0° orientation seem to be good alternatives to the traditional honeycombs used in sandwich composite panels for those industrial applications where low weight, high stiffness, and large energy-absorbing capacity are required.

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