scholarly journals Development of Lightweight Magnesium/Glass Micro Balloon Syntactic Foams Using Microwave Approach with Superior Thermal and Mechanical Properties

Metals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 827
Author(s):  
Akshay Padnuru Sripathy ◽  
Cindy Handjaja ◽  
Vyasaraj Manakari ◽  
Gururaj Parande ◽  
Manoj Gupta
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Compression Strength ◽  
Fracture Strain ◽  
Coefficient Of Thermal Expansion ◽  
Microwave Sintering ◽  
Syntactic Foams ◽  
Secondary Phases ◽  
Magnesium Matrix ◽  
Ultimate Compression Strength

Magnesium matrix syntactic foams (MgMSFs) are emerging lightweight materials with unique capabilities to exhibit remarkable thermal, acoustic, and mechanical properties. In the current study, lightweight glass micro balloon (GMB)-reinforced Mg syntactic foams were synthesized via the powder metallurgy technique using hybrid microwave sintering. The processing employed in the study yielded MgMSFs with refined grain sizes, no secondary phases, and reasonably uniform distributions of hollow reinforcement particles. The developed MgMSFs exhibited densities 8, 16, and 26% lower than that of the pure Mg. The coefficient of thermal expansion reduced (up to 20%) while the ignition resistance improved (up to 20 °C) with the amount of GMB in the magnesium matrix. The MgMSFs also exhibited a progressive increase in hardness with the amount of GMB. Although the MgMSFs showed a decrease in the yield strength with the addition of GMB hollow particles, the ultimate compression strength, fracture strain, and energy absorption capabilities increased noticeably. The best ultimate compression strength at 321 MPa, which was ~26% higher than that of the pure Mg, was displayed by the Mg-5GMB composite, while the Mg-20GMB composite showed the best fracture strain and energy absorption capability, which were higher by ~39 and 65%, respectively, when compared to pure Mg. The specific strength of all composites remained superior to that of monolithic magnesium. Particular efforts were made in the present study to interrelate the processing, microstructural features, and properties of MgMSFs.

scholarly journals Microstructure and Mechanical Properties of Hypo- and Hypereutectic Cast Mg/Mg2Si Composites

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3591
Author(s):  
Katarzyna N. Braszczyńska-Malik ◽  
Marcin A. Malik
Keyword(s):  
Mechanical Properties ◽  
Compression Strength ◽  
Eutectic Mixture ◽  
Weight Fraction ◽  
Uniaxial Tensile ◽  
Compression Tests ◽  
Magnesium Matrix ◽  
Magnesium Matrix Composites ◽  
Mg2si Phase ◽  
Microstructure And Mechanical Properties

In this paper, the microstructure and mechanical properties of two magnesium matrix composites—a hypoeutectic with 1.9 wt% Mg2Si phase and a hypereutectic with 19 wt% Mg2Si compound—were analyzed. The investigated materials were prepared using the gravity casting method. Microstructure analyses of the fabricated composites were carried out by XRD and light microscopy. The tensile and compression strength as well as yield strength of the composites were examined in both uniaxial tensile and compression tests. The microstructure of the hypoeutectic composite was in agreement with the phase diagram and composed of primary Mg dendrites and an Mg–Mg2Si eutectic mixture. For the hypereutectic composite, besides the primary Mg2Si phase and eutectic mixture, additional magnesium dendrites surrounding the Mg2Si compound were observed due to nonequilibrium solidification conditions. The composites exhibited a rise in the examined mechanical properties with an increase in the Mg2Si weight fraction and also a higher tensile and compression strength in comparison to the pure magnesium matrix (cast in the same conditions). Additionally, analyses of fracture surfaces of the composites carried out using scanning electron microscopy (SEM + EDX) are presented.

Controlling of Distribution of Mechanical Properties in Functionally-Graded Syntactic Foams for Impact Energy Absorption

2012 ◽  
Vol 706-709 ◽  
pp. 729-734 ◽  
Author(s):  
Masahiro Higuchi ◽  
Tadaharu Adachi ◽  
Yuto Yokochi ◽  
Kenta Fujimoto
Keyword(s):  
Mechanical Properties ◽  
Density Distribution ◽  
Energy Absorption ◽  
Impact Energy ◽  
Volume Fraction ◽  
Functionally Graded ◽  
Syntactic Foams ◽  
Compression Tests ◽  
Density Distributions ◽  
Control Distribution

In the study, novel fabrication processes of functionally-graded (FG) syntactic foams were developed to control distribution of the mechanical properties in the FG foams for highly impact energy absorption. In order to control mechanical properties, the density distributions in FG foams were graded by floating phenomenon of the light-weight micro-balloons in matrix resin during curing process. The density distribution in the foam could be controlled by adjusting the average volume fraction and the turning procedure of the mold before grading the micro-balloons in the foam. The compression tests of the fabricated FG foams suggested that the foams had high absorption of impact energy since the foams collapsed progressively due to the grading of the density distribution.

Microwave Synthesis and Characterization of Magnesium Based Composites Containing Nanosized SiC and Hybrid (SiC+Al2O3) Reinforcements

2006 ◽  
Vol 129 (2) ◽  
pp. 194-199 ◽  
Author(s):  
Sanjay Kumar Thakur ◽  
K. Balasubramanian ◽  
Manoj Gupta
Keyword(s):  
Brittle Failure ◽  
Failure Strain ◽  
Coefficient Of Thermal Expansion ◽  
Microwave Sintering ◽  
Hot Extrusion ◽  
Magnesium Matrix ◽  
The Matrix ◽  
Al2o3 Particles ◽  
Powder Metallurgy Route

In the present study, monolithic magnesium, nanosized SiC reinforced magnesium and nanosized hybrid (SiC+Al2O3) reinforced magnesium materials have been synthesized by using powder metallurgy route involving microwave sintering followed by hot extrusion. The results show that the monolithic and the reinforced magnesium materials have minimal porosity and the reinforced magnesium materials have fairly well distributed nanosized SiC and SiC+Al2O3 particles in the matrix. The thermo-mechanical property measured in terms of coefficient of thermal expansion of the reinforced magnesium shows dimensionally more stable magnesium as compared to monolithic magnesium. The hardness 0.2% YS and UTS were found to improve significantly after addition of nanosized SiC and nanosized hybrid SiC+Al2O3 particles to the magnesium, However, ductility measured in terms of failure strain was found to be marginally reduced. Fractography results showed the presence of brittle failure mode with cleavage steps on the fractured surface of the magnesium matrix.

Investigation of Fracture Behavior of Piezoelectric Ceramics Embedded in Metal Matrix

2020 ◽  
Author(s):  
Karin Iijima ◽  
Tetsuro Yanaseko ◽  
Isao Kuboki ◽  
Hiroshi Sato ◽  
Hiroshi Asanuma
Keyword(s):  
Mechanical Properties ◽  
Metal Matrix ◽  
Fracture Strain ◽  
Coefficient Of Thermal Expansion ◽  
Piezoelectric Ceramics ◽  
Piezoelectric Sensors ◽  
Bending Test ◽  
Piezoelectric Composite ◽  
Aluminum Composite ◽  
The Matrix

Abstract In recent years, there is considerable interest in the Structural health monitoring. This is a technique to diagnose and evaluate the damage and deterioration of a structure by attaching sensors to the structure, and is useful for judging whether building can be reused or not at that time of a disaster such as an earthquake. There are several types of sensors such as piezoelectric type, optical fiber and strain gauge type and piezoelectric sensors are very suitable for this purpose because they do not require an energy source considering that they produce electrical power by themselves. However, the application range of piezoelectric ceramics used for piezoelectric sensors is narrow because of its fragility. Then, the researches and developments of the piezoelectric ceramics embedded in the matrix that has excellent mechanical strength are carried out. The metal-core piezoelectric fiber/aluminum composite was developed by Asanuma et al. to overcome the problems associated with piezoelectric ceramics, such as poor mechanical properties, reliability; brittleness and low fracture strain. The fracture strain of piezoelectric ceramics fiber significantly improved due to residual compressive stress caused by difference of coefficient of thermal expansion between the ceramics and the matrix during embedding process. However, there is few statistical data on the mechanical properties of piezoelectric ceramic fibers, and the improvement in the properties due to the embedding has not been quantitatively evaluated. In this study, to overcome this problem, the simplified model of metal matrix piezoelectric composite was fabricated and used to compare strengths before and after embedding by 3-point bending test. As a result, it is found that Weibull parameters of piezoelectric ceramics are improved by embedding in the matrix.

Effect of Titanium Carbide Particles on Mechanical Properties of Aluminum Matrix Composites

2017 ◽  
Vol 5 (2) ◽  
pp. 20-30
Author(s):  
Zaman Khalil Ibrahim
Keyword(s):  
Mechanical Properties ◽  
Titanium Carbide ◽  
Compression Strength ◽  
Volume Fraction ◽  
Aluminum Matrix ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Powder Metallurgy Technique ◽  
Carbide Particles ◽  
Properties Of Composites

In this research aluminum matrix composites (AMCs) was reinforced by titanium carbide (TiC) particles and was produced. Powder metallurgy technique (PM) has been used to fabricate AMCs reinforced with various amounts (0%, 4%, 8%, 12%, 16% and 20% volume fraction) of TiC particles to study the effect of different volume fractions on mechanical properties of the Al-TiC composites. Measurements of compression strength and hardness showed that mechanical properties of composites increased with an increase in volume fraction of TiC Particles. Al-20 % vol. TiC composites exhibited the best properties with hardness value (97HRB) and compression strength value (275Mpa).

scholarly journals Study on improvement of prefolded energy absorption device to constant resistance and its mechanical properties

2021 ◽  
Vol 104 (3) ◽  
pp. 003685042110368
Author(s):  
Dong An ◽  
Jiaqi Song ◽  
Hailiang Xu ◽  
Jingzong Zhang ◽  
Yimin Song ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Absorption ◽  
Compression Test ◽  
Side Wall ◽  
Concave Side ◽  
Displacement Curve ◽  
Static Compression ◽  
Constant Resistance ◽  
The Impact ◽  
Force Displacement

When the rock burst occurs, energy absorption support is an important method to solve the impact failure. To achieve constant resistance performance of energy absorption device, as an important component of the support, the mechanical properties of one kind of prefolded tube is analyzed by quasi-static compression test. The deformation process of compression test is simulated by ABAQUS and plastic strain nephogram of the numerical model are studied. It is found that the main factors affecting the fluctuation of force-displacement curve is the stiffness of concave side wall. The original tube is improved to constant resistance by changing the side wall. The friction coefficient affects the folding order and form of the energy absorbing device. Lifting the concave side wall stiffness can improve the overall stiffness of energy absorption device and slow down the falling section of force-displacement curve. It is always squeezed by adjacent convex side wall in the process of folding, with large plastic deformation. Compared with the original one, the improved prefolded tube designed in this paper can keep the maximum bearing capacity ( Pmax), increase the total energy absorption ( E), improve the specific energy absorption (SEA), and decrease the variance ( S2) of force-displacement curve.

scholarly journals Mechanical Properties of Al Matrix Composite Enhanced by In Situ Formed SiC, MgAl2O4, and MgO via Casting Process

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1767
Author(s):  
Yuhong Jiao ◽  
Jianfeng Zhu ◽  
Xuelin Li ◽  
Chunjie Shi ◽  
Bo Lu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Matrix Composite ◽  
Compression Strength ◽  
Casting Process ◽  
Al Alloy ◽  
Pyrolysis Process ◽  
Alloy Matrix ◽  
Al Matrix Composite ◽  
Al Matrix

Al matrix composite, reinforced with the in situ synthesized 3C–SiC, MgAl2O4, and MgO grains, was produced via the casting process using phenolic resin pyrolysis products in flash mode. The contents and microstructure of the composites’ fracture characteristics were analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Mechanical properties were tested by universal testing machine. Owing to the strong propulsion formed in turbulent flow in the pyrolysis process, nano-ceramic grains were formed in the resin pyrolysis process and simultaneously were homogeneously scattered in the alloy matrix. Thermodynamic calculation supported that the gas products, as carbon and oxygen sources, had a different chemical activity on in situ growth. In addition, ceramic (3C–SiC, MgAl2O4, and MgO) grains have discrepant contents. Resin pyrolysis in the molten alloy decreased oxide slag but increased pores in the alloy matrix. Tensile strength (142.6 ± 3.5 MPa) had no change due to the cooperative action of increased pores and fine grains; the bending and compression strength was increasing under increased contents of ceramic grains; the maximum bending strength was 378.2 MPa in 1.5% resin-added samples; and the maximum compression strength was 299.4 MPa. Lath-shaped Si was the primary effect factor of mechanical properties. The failure mechanism was controlled by transcrystalline rupture mechanism. We explain that the effects of the ceramic grains formed in the hot process at the condition of the resin exist in mold or other accessory materials. Meanwhile, a novel ceramic-reinforced Al matrix was provided. The organic gas was an excellent source of carbon, nitrogen, and oxygen to in situ ceramic grains in Al alloy.

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