Characterization of Mg/MgO Nanocomposites Synthesized Using Powder Metallurgy Technique

Materials ◽  
2005 ◽  
Author(s):  
C. S. Goh ◽  
J. Wei ◽  
M. Gupta

Magnesium nanocomposites with 0.1, 0.2, 0.3 and 0.4 volume percentages of MgO were synthesized using the powder metallurgy technique. The nanocomposite billets obtained were subsequently hot extruded at a temperature of 350 °C with an extrusion ratio of 20.25:1. The extruded nanocomposites were characterized for their microstructural, physical and mechanical properties. The microstructures of the nanocomposites showed individual particles of MgO uniformly distributed in the magnesium matrix. The thermomechanical analysis results revealed that a more thermally stable magnesium nanocomposite could be obtained with a threshold amount of MgO. The tensile properties results indicated that the yield strength peaks at 0.3 vol.% of reinforcement incorporated, with an improvement of approximately 17%. An attempt is made to correlate the volume fraction of the MgO with the resultant physical and mechanical properties of the magnesium nanocomposites.

Author(s):  
M. A. Salem ◽  
I. G. El-Batanony ◽  
M. Ghanem ◽  
Mohamed Ibrahim Abd ElAal

Different Al-SiC metal matrix composites (MMCs) with a different matrix, reinforcement sizes, and volume fractions were fabricated using ball milling (BM) and powder metallurgy (PM) techniques. Al and Al-SiC composites with different volume fractions were milled for 120 h. Then, the Al and Al-SiC composites were pressed under 125 MPa and finally sintered at 450 °C. Moreover, microsize and combination between micro and nano sizes Al-SiC samples were prepared by the same way. The effect of the Al matrix, SiC reinforcement sizes and the SiC volume fraction on the microstructure evolution, physical and mechanical properties of the produced composites was investigated. The BM and powder metallurgy techniques followed by sintering produce fully dense Al-SiC composite samples with different matrix and reinforcement sizes. The SiC particle size was observed to have a higher effect on the thermal conductivity, electrical resistivity, and microhardness of the produced composites than that of the SiC volume fraction. The decreasing of the Al and SiC particle sizes and increasing of the SiC volume fraction deteriorate the physical properties. On the other hand, the microhardness was enhanced with the decreasing of the Al, SiC particle sizes and the increasing of the SiC volume fraction.


Author(s):  
C. S. Goh ◽  
J. Wei ◽  
M. Gupta

Powder metallurgy and liquid metallurgy techniques were used to fabricate Mg reinforced with different volume fraction of nano-size MgO particles. A higher volume fraction of MgO particles could be added into the Mg matrix when the liquid metallurgy technique was used. Microstructural analysis was carried out to examine the distribution of the nanoparticles in the Mg matrix when different processing routes were chosen. Individual particles together with sparsely distributed agglomerations could be discerned in the Mg matrix for both processing routes. Mechanical properties results revealed that a more substantial improvement in macrohardness and tensile properties could be achieved by using the liquid metallurgy route where a higher amount of nano-size MgO particles could be incorporated.


2021 ◽  
Vol 26 (4) ◽  
Author(s):  
Mayara Ribeiro Masseli ◽  
Bruna Horta Bastos Kuffner ◽  
Lucas Victor Benjamim Vasconcelos ◽  
Gilbert Silva ◽  
Daniela Sachs

ABSTRACT The hydroxyapatite calcium phosphate based ceramic (Hap) is widely used for bone repair, as it is a biocompatible biomaterial and because it has osteoconductive and osteoinductive properties. However, the low mechanical strength of Hap may limit its applicability. Thus, the present work aims to improve the mechanical properties of Hap, associating it with alumina (Al2O3), using the powder metallurgy technique, which consists in the milling of the precursor powders in a planetary ball mill, uniaxial pressing and sintering. The microstructure and mechanical strength of the sintered samples were evaluated using density, microhardness, compressive strength and wettability tests. It was concluded that the use of Al2O3 in the composite improves the mechanical properties of Hap, while decreases its hydrophilic potential. Thus, the composition with 40% Hap / 60% Al2O3 was considered the best for biomedical applications.


2012 ◽  
Vol 59 (2) ◽  
Author(s):  
Ahmad Aswad Mahaidin ◽  
Mohd Asri Selamat ◽  
Samsiah Abdul Manaf ◽  
Talib Ria Jaafar

The mechanical properties of WC-Co are highly dependent on its cobalt content, density and grain size of the WC particles. Addition of free carbon during the consolidation of process is said to improve the densification process and inhibit grain growth. However, there are still plenty of works needs to be done regarding this matter to support the fact. Therefore, this study is to evaluate the effect of carbon addition on the physical and mechanical properties of WC-Co-C sintered powders. The WC-Co-C sample is fabricated using powder metallurgy technique, in which the powders were uniaxially pressed at 625 MPa and cold-isostatic pressed at 200 MPa. Then, the sample is sintered in nitrogen-based atmosphere at temperature range of 1350-1450C. The physical and mechanical properties of the WC-Co sintered powders were analysed. It is found that WC-Co-C has a relatively higher density and hardness but exhibit lower transverse rupture strength compared to WC-Co.


2007 ◽  
Vol 129 (3) ◽  
pp. 462-467 ◽  
Author(s):  
S. F. Hassan ◽  
M. Gupta

Nano-Y2O3 particulates containing ductile magnesium nanocomposites were synthesized using blend-press-sinter powder metallurgy technique followed by hot extrusion. Microstructural characterization of the nanocomposite samples showed fairly uniform reinforcement distribution, good reinforcement-matrix interfacial integrity, significant grain refinement of magnesium matrix with increasing presence of reinforcement, and the presence of minimal porosity. Mechanical properties characterization revealed that the presence of nano-Y2O3 reinforcement leads to marginal increases in hardness, 0.2% yield strength and ultimate tensile strength, but a significant increase in ductility and work of fracture of magnesium. The fracture mode was changed from brittle for pure Mg to mix ductile and intergranular in the case of nanocomposites.


Materials ◽  
2005 ◽  
Author(s):  
W. L. E. Wong ◽  
M. Gupta

In the present study, magnesium composites containing different amount of nano-size copper particulates were successfully synthesized using powder metallurgy technique coupled with a novel microwave assisted rapid sintering. Mg/Cu nanocomposites were sintered using a hybrid heating method consisting of microwaves and radiant heat from external susceptors. The sintered specimens were hot extruded and characterized in terms of microstructural, physical and mechanical properties. Microstructural characterization revealed minimal porosity and the presence of a continuous network of nano-size Cu particulates decorating the particle boundaries of the metal matrix. Mechanical characterization revealed that the addition of nano-size Cu particulates lead to an increase in hardness, 0.2% yield strength (YS) and ultimate tensile strength (UTS) of the matrix. An attempt is made in the present study to correlate the effect of increasing presence of nano-size Cu reinforcement on the microstructural, physical and mechanical properties of monolithic magnesium.


2006 ◽  
Vol 111 ◽  
pp. 179-182 ◽  
Author(s):  
C.S. Goh ◽  
Jun Wei ◽  
L.C. Lee ◽  
Manoj Gupta

In this study, both liquid and powder metallurgy techniques were employed to fabricate Mg nanocomposites. Comparisons were made on the physical and mechanical properties of Mg nanocomposites using these two different fabrication techniques. When similar weight fractions of carbon nanotubes (CNTs) were added to Mg using these two different techniques, the nanocomposites fabricated using powder metallurgy technique were found to be thermally more stable and has higher yield and tensile strengths than those produced using liquid metallurgy technique. The higher yield and tensile strengths were due to the presence of MgO particles which were pre-existent in the Mg powders. The MgO particles cause a hybrid reinforcement effect in the Mg-CNT nanocomposites, which surpasses the strengthening effect of the CNTs alone.


Author(s):  
Thais Helena Sydenstricker Flores-Sahagun ◽  
Kelly Priscila Agapito ◽  
ROSA MARIA JIMENEZ AMEZCUA ◽  
Felipe Jedyn

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