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).

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.

Effect of Ca and Sr Content on Elevated Temperatures Mechanical Properties of a Cast AZ91 Magnesium Alloy

2007 ◽  
Vol 26-28 ◽  
pp. 141-144
Author(s):  
Ippei Takeuchi ◽  
Kinji Hirai ◽  
Yorinobu Takigawa ◽  
Tokuteru Uesugi ◽  
Kenji Higashi
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Creep Resistance ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Tensile Tests ◽  
Az91 Magnesium Alloy ◽  
Additional Amount ◽  
Az91 Magnesium ◽  
Second Phases

The effect of Ca and Sr content on the microstructure and mechanical properties of a cast AZ91 magnesium alloy is investigated. Ca and Sr additions in AZ91 magnesium alloy are expected high creep resistance. The microstructure of the alloy exhibits the dendritic α-matrix and the second-phases forming networks on the grain boundary. Tensile tests at elevated temperatures between 448 and 523K reveal that the creep resistance was improved with increasing the additional amount of Ca, especially more than 1.0wt%. From the perspective of grain refinement effect, it is expected that the additions of Ca and Sr to AZ91 magnesium alloy not only improve creep resistance but also improve mechanical properties 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.

scholarly journals Technological Relevance, Research Prospect and Applications of Aluminium-Silicon Carbide-Graphite Hybrid Metal Matrix Composites for Thermal Characterization

2018 ◽  
Vol 8 (02) ◽  
Author(s):  
S A Mohan Krishna ◽  
T N Shridhar ◽  
L Krishnamurthy ◽  
K B Vinay ◽  
G V Naveen Prakash
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Silicon Carbide ◽  
Thermal Expansion ◽  
Hybrid Composites ◽  
Coefficient Of Thermal Expansion ◽  
Aluminium Matrix ◽  
Matrix Composites ◽  
Aluminium Matrix Composites ◽  
Research Prospect

Aluminium matrix composites belong to the family of materials whose mechanical, tribological, thermal and electrical properties can be customized effectively. Most of the commercial work on MMCs has been highlighted on Aluminium as the matrix material. The combination of light weight, environmental resistance and beneficial mechanical properties has made Aluminium alloys exceedingly popular; these properties also make Aluminium best suited for use as a matrix metal. The thermophysical properties of these composites can be tailor made and have excellent specific mechanical properties. These composites can be fabricated with ease. Aluminium matrix composites reinforced with the particles of Silicon Carbide possess high yield strength, low coefficient of thermal expansion or thermal expansivity, high modulus of elasticity and excellent wear resistance by maintaining volume proportion up to 20%. Aluminium hybrid composites can be customized to provide moderate Coefficient of Thermal Expansion (CTE) and high thermal conductivity that are favorable for the applications pertaining to thermal management equipment. However, it is necessary to evaluate different percentage combinations of reinforcements with matrix Aluminium to check for thermal stability and to measure thermal conductivity and coefficient of thermal expansion. It is expected that, Aluminium-Silicon Carbide-Graphite hybrid composites can be used as load bearing material for the above applications. In this paper, a review about the said hybrid composites to investigate thermal properties for engineering applications have been discussed based on its technological relevance, applications and research prospect.

Enhancing mechanical properties of squeeze-cast AZ91 magnesium alloy by combined additions of Sb and SiC nanoparticles

2021 ◽  
Vol 799 ◽  
pp. 140341
Author(s):  
Sourav Ganguly ◽  
Sureddy Tejanath Reddy ◽  
Jichil Majhi ◽  
Purnendu Nasker ◽  
A.K. Mondal
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloy ◽  
Az91 Magnesium Alloy ◽  
Sic Nanoparticles ◽  
Squeeze Cast ◽  
Az91 Magnesium

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.

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.

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

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

Mechanical Properties of Extruded and ECAP Processed Magnesium Alloy AZ91 at Elevated Temperature

2017 ◽  
Vol 891 ◽  
pp. 366-371 ◽  
Author(s):  
Roman Štěpánek ◽  
Libor Pantělejev ◽  
Ehsan Mostaed ◽  
Maurizio Vedani
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
Tensile Tests ◽  
Az91 Magnesium Alloy ◽  
Magnesium Alloy Az91 ◽  
Az91 Magnesium ◽  
Reduction Of Area ◽  
Increasing Temperature

In this paper tensile properties at elevated temperature of extruded AZ91 magnesium alloy and the same alloy further processed by ECAP (exECAP) are compared. The tensile tests were performed at room temperature and for the temperature range of 100 to 300 °C. Loading speed 2 mm/min was used for the tests. At room temperature mechanical properties except elongation were slightly higher for extruded material yet still very similar to properties of exECAPed material. Overall trend of properties evolution with increasing temperature was also similar but the decrease of strength or the increase of elongation and reduction of area respectively is more intensive for exECAPed material. Elongation of exECAPed material exceeded elongation of extruded material more than twice at 300 °C and with value of ~260% this alloy exhibited pseudosuperplastic behavior.

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