Fluxless Recycling of Die-Cast AZ91 Magnesium Alloy Scrap

2005 ◽  
Vol 475-479 ◽  
pp. 541-544 ◽  
Author(s):  
Hwa Chul Jung ◽  
Young Cheol Lee ◽  
Kwang Seon Shin
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Die Casting ◽  
Casting Process ◽  
Az91 Alloy ◽  
Main Concern ◽  
Az91 Magnesium Alloy ◽  
Die Cast ◽  
Class 1 ◽  
High Level

Magnesium die-casting has experienced dramatic growth over the past decade and the recycling of magnesium scrap has become increasingly important due to the generation of substantial quantities of scrap in the die-casting process. Magnesium is a readily recyclable material and the recycling of magnesium scrap is crucial in making magnesium more competitive. The main concern associated with using the secondary magnesium is the high level of Fe content and oxide inclusions that are detrimental to the corrosion and mechanical properties of the secondary alloy. In this study, the die-cast specimens were produced using the recycled class 1 scrap which is refined by means of Ar bubbling and Mn addition without using refining fluxes, and their mechanical properties and corrosion characteristics were investigated. The results showed that the tensile properties of the secondary AZ91 alloy were equivalent to those of the primary magnesium alloy after appropriate treatments. The corrosion resistance of the recycled magnesium was also found to increase by Ar bubbling and Mn addition.

Mechanical Properties of Twin Roll Cast AZ91 Magnesium Alloy at Room Temperature

2007 ◽  
Vol 26-28 ◽  
pp. 145-148 ◽  
Author(s):  
Shu Hei Uchida ◽  
Ippei Takeuchi ◽  
Gentaro Gonda ◽  
Kinji Hirai ◽  
Tokuteru Uesugi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Cast Alloy ◽  
Casting Process ◽  
Az91 Magnesium Alloy ◽  
Die Cast ◽  
Az91 Magnesium ◽  
Twin Roll Cast ◽  
Twin Roll

Twin roll casting process combines casting and hot rolling into a single process. In this study, mechanical properties at room temperature and microstructure of the twin roll cast AZ91 magnesium alloy are investigated. The alloy exhibited a good combination of high ultimate strength of 343MPa, yield stress of 224MPa and elongation to failure of 13%. The mechanical property was very excellent compared with AZ91 die-cast alloy. EPMA analysis reveals that the Al concentration in Mg matrix is higher in twin roll cast alloy than that in die-cast alloy. This high Al concentration must be the origin of the good mechanical properties of twin roll cast alloy at room temperature.

Effects of CaCO3 Modificator on Microstructure and Mechanical Properties of Cast AZ91 Magnesium Alloy

2007 ◽  
Vol 546-549 ◽  
pp. 155-158
Author(s):  
Qu Dong Wang ◽  
Yang Zhao ◽  
Qing Hua Li
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Cleavage Fracture ◽  
Tensile Fracture ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Microstructure And Mechanical Properties ◽  
Reticular Structure ◽  
Az91 Magnesium ◽  
Alloy Increase

Effects of CaCO3 modificator on microstructure and mechanical properties of cast AZ91 Magnesium alloy have been investigated. Tensile fracture behavior of AZ91 alloys modified by CaCO3 has also been studied. Results show that CaCO3 modificator can obviously refine the grain of AZ91 magnesium alloy and Mg17Al12. Mg17Al12 in grain boundary of AZ91 alloy after modified by CaCO3 changes from continuous reticular structure to discontinuous reticular structure, even so much as granular structure and rod structure. After modified by 0.5wt% CaCO3 modificator, ultimate tensile strength, yield strength, impact toughness and elongation of AZ91 alloy increase from 186MPa to 200MPa, from 147MPa to 160MPa, from 4J to 9J and from 2.6% to 5%, respectively. And 0.5wt% CaCO3 modificator brings about an optimal refining effect. The study also shows that the fracture mechanism of modified AZ91 alloy is between cleavage fracture and quasi-cleavage fracture, which is as same as that of unmodified AZ91 alloy.

Effect of Cerium-Rich Mischmetal Addition on the Microstructure and Properties of Die-Cast Mg-Alloys

2013 ◽  
Vol 772 ◽  
pp. 103-106
Author(s):  
De Ping Jiang ◽  
Zong Xiang Yao
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Die Casting ◽  
Microstructure And Properties ◽  
Die Cast ◽  
Series Of Experiments ◽  
Optimal Values ◽  
New Phase ◽  
Addition Amount

Effects of Cerium-rich mischmetal addition on the microstructure and properties of die casting magnesium alloy were investigated in the series of experiments. The results indicate that a new phase appeared in the microstructure with the additional of mischmetal .The new phase Al11(Ce,La)3can not only refine the grains, but also affect the mechanical properties of the alloys. The effect degree was different with the diffetent Al concentration When the Al concentration was 8%, and the addition amount of the Cerium-rich mischmetal was 1.5%, the properties of fhe alloys reached its optimal values at room temperature.

scholarly journals Tensile Mechanical Properties and Strengthening Mechanism of Hybrid Carbon Nanotube and Silicon Carbide Nanoparticle-Reinforced Magnesium Alloy Composites

2012 ◽  
Vol 2012 ◽  
pp. 1-7 ◽  
Author(s):  
Xia Zhou ◽  
Depeng Su ◽  
Chengwei Wu ◽  
Liming Liu
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Hybrid Composites ◽  
Coefficient Of Thermal Expansion ◽  
Strengthening Mechanism ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Sic Nanoparticles

AZ91 magnesium alloy hybrid composites reinforced with different hybrid ratios of carbon nanotubes (CNTs) and silicon carbide (SiC) nanoparticulates were fabricated by semisolid stirring assisted ultrasonic cavitation. The results showed that grains of the matrix in the AZ91/(CNT + SiC) composites were obviously refined after adding hybrid CNTs and SiC nanoparticles to the AZ91 alloy, and the room-temperature mechanical properties of AZ91/(CNT + SiC) hybrid composites were improved comparing with the unreinforced AZ91 matrix. In addition, the tensile mechanical properties of the AZ91 alloy-based hybrid composites were considerably improved at the mass hybrid ratio of 7 : 3 for CNTs and SiC nanoparticles; in particular, the tensile and yield strength were increased, respectively, by about 45 and 55% after gravity permanent mould casting. The reason for an increase in the room-temperature strength of the hybrid composites should be mainly attributable to the larger hybrid ratio of CNTs and SiC nanoparticles, the coefficient of thermal expansion (CTE) mismatch between matrix and hybrid reinforcements, the dispersive strengthening effects (Orowan strengthening), and the grain refining (Hall-Petch effect).

Effects of La on the Microstructures and Mechanical Properties of AZ91 Magnesium Alloy and its Mechanism

2011 ◽  
Vol 328-330 ◽  
pp. 1650-1653 ◽  
Author(s):  
Jin Ling Zhang ◽  
She Bin Wang ◽  
Xiao Ye Qi ◽  
Bing She Xu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Yield Strength ◽  
Maximum Yield ◽  
Az91 Alloy ◽  
Strengthening Effect ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium ◽  
Maximum Yield Strength

Microstructure changes brought by the addition of La element to AZ91 magnesium alloy are studied, also, the precipitating phases were identified and their influence on the mechanical properties of alloys was investigated. Results show La makes refinement of microstructure of the AZ91 alloy, and decrease the size of Mg17Al12 phase. La element takes a priority to react with Al element over Mg, forming binary phase Al11La3 with high melting point. Certain amount of La increases tensile strength, yield strength and elongation. With more addition, La would combine more Al in matrix and decrease strengthening effect, because Al11La3 phase would become coarsening. The mechanical poroerties tests indicate that AZ91+0.16%La alloy has the best properties. Maximum tensile strength, maximum yield strength and elongation are 245MPa, 178MPa and 14.5% respective, increased by 21%, 19% and 48% respectively. The mechanism of La strenthing mechanical properties is proposed that Al11La3 phase enriched on solid-liquid interface, increased the degree of supercooling, refined the grain size and changed the crystal style.

Effects of Hot Extrusion and Heat Treatment on Mechanical Properties and Microstructures of AZ91 Magnesium Alloy

2012 ◽  
Vol 562-564 ◽  
pp. 242-245 ◽  
Author(s):  
Ming Tan ◽  
Zhao Ming Liu ◽  
Gao Feng Quan
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Magnesium Alloy ◽  
Solution Treatment ◽  
Annealing Treatment ◽  
Aging Treatment ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium

The effects of heat treatment on the microstructure, tensile property and fracture behavior of as-extruded AZ91 magnesium alloy were studied by OM and SEM. The results show that the grain of as-cast AZ91 alloy is refined by extruding and dynamic recrystallization, and the mechanical properties increase obviously. The ductility is significantly enhanced after solution treatment of the as-extruded AZ91 alloy, tensile strength is almost the same before and hardness is significantly reduced after solution treatment and artificial aging treatment. The tensile strength reduced and the ductility is significantly enhanced of as-extruded AZ91 magnesium alloy after annealing processes. The fracture surface of as-extruded AZ91 magnesium alloy has the mixture of ductile and brittle characteristic. But after T6 or annealing treatment, its dimple number increases evidently.

scholarly journals Effect of Modification on Microstructure and Properties of AZ91 Magnesium Alloy

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 536
Author(s):  
Andrzej Kiełbus ◽  
Robert Jarosz ◽  
Adam Gryc
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Magnesium Alloy ◽  
Volume Fraction ◽  
Az91 Alloy ◽  
Carbon Powder ◽  
Az91 Magnesium Alloy ◽  
Microstructure And Properties ◽  
Az91 Magnesium ◽  
Cast Magnesium

Refinement of α-Mg solid solution grains has a significant influence on the improvement of mechanical properties of cast magnesium alloys. In the article, the effects of three modifiers on microstructure and properties of AZ91 magnesium alloy casted to a sand mould were described. Overheating, hexachloroethane and wax-CaF2-carbon powder were applied. The research procedure comprised microstructure analysis by means of light microscopy, scanning electron microscopy and quantitative analysis with AnalySIS Pro® software and mechanical properties’ investigation. The microstructure of AZ91 alloy in the as-cast condition consists of α-Mg solid solution with precipitates of Mg17Al12, Mg2Si and Al8Mn5 phases. It was reported that all applied modifiers cause refinement of α-Mg solid solution grains and a decrease of the volume fraction of α-Mg+Mg17Al12 compound discontinuous precipitates. The best results were obtained in the case of wax-CaF2-carbon powder.

scholarly journals Investigation of the Influence of Open-Die Forging Parameters on the Flow Kinetics of AZ91 Magnesium Alloy

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4010
Author(s):  
Grzegorz Banaszek ◽  
Teresa Bajor ◽  
Anna Kawałek ◽  
Tomasz Garstka
Keyword(s):  
Magnesium Alloy ◽  
Operation Time ◽  
Strength Properties ◽  
Hydraulic Press ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Numerical Tests ◽  
Az91 Magnesium ◽  
Product Manufacturing ◽  
Open Die Forging

This paper presents the results of numerical tests of the process of forging magnesium alloy ingots (AZ91) on a hydraulic press with the use of flat and proprietary shaped anvils. The analysis of the hydrostatic pressure distribution and the deformation intensity was carried out. It is one of the elements used for determining the assumptions for the technology of forging to obtain a semi-finished product from the AZ91 alloy with good strength properties. The aim of the research was to reduce the number of forging passes, which will shorten the operation time and reduce the product manufacturing costs. Numerical tests of the AZ91 magnesium alloy were carried out using commercial Forge®NxT software.

Development of 2-Cavity Die Casting Process for AM50 Mg Steering Column Lock Housing Module

2006 ◽  
Vol 510-511 ◽  
pp. 334-337
Author(s):  
Shae K. Kim
Keyword(s):  
Magnesium Alloy ◽  
Aluminum Alloys ◽  
Magnesium Alloys ◽  
Weight Reduction ◽  
Die Casting ◽  
Casting Process ◽  
Research Strategy ◽  
Good Choice ◽  
Weight Basis ◽  
Die Casting Process

It is obvious that automotive industry worldwide is predicting significant growth in the use of magnesium alloys for weight reduction to decrease fuel consumption and emission. About a half decade ago, the price of magnesium alloys was more than twice that of aluminum alloys on a weight basis. Currently, magnesium alloys cost about one and a half times that of aluminum alloys on a weight basis, and thus the price of magnesium alloys is the same as or lower than that of aluminum alloys on a per volume basis. However, in considering the performance of magnesium components (not their specific mechanical properties) and recycling aspect of magnesium alloys, it is required to realize niche applications of magnesium alloys, which meet the cost requirement on performance basis and/or offer more than weight reduction. There are many other factors that make magnesium a good choice: component consolidation, improved safety for driver and passengers, and improved noise vibration and harshness (NVH), to name a few. As one of these efforts to adopt magnesium alloys in automotive component, this paper describes the research strategy of cold chamber type 2-cavity die casting of AM50 magnesium alloy for developing the steering column lock housing module with emphasis on cost driving factors and necessities for cost reduction, explaining why AM50 magnesium alloy is chosen with design and die casting process optimization.

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