Un-Bundled Carbon Nanotubes Reinforced Light Metal Composites via Powder Metallurgy Route

2011 ◽  
Vol 690 ◽  
pp. 339-342
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Hiroyuki Fukuda ◽  
Junko Umeda
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Powder Metallurgy ◽  
Pure Titanium ◽  
Hot Extrusion ◽  
Light Metal ◽  
Dispersion Strengthening ◽  
Multi Wall Carbon Nanotubes

By using light metal (Mg, Al, Ti) powders coated with un-bundled multi-wall carbon nanotubes (MWCNTs) via wet process, powder metallurgy (P/M) light metal matrix composite reinforced with un-bundled nanotubes was prepared by spark plasma sintering (SPS) and subsequently hot extrusion process. The microstructure and mechanical properties of the composites were evaluated. In the case of pure titanium, the distribution of CNTs and in-situ formed titanium carbide (TiC) compounds during sintering was investigated by optical and scanning electron microscopy (SEM) equipped with EDS analyzer. The mechanical properties of TMC were significantly improved by the additive of CNTs. For example, when employing the pure titanium composite powder coated with CNTs of 0.35 mass%, the increase of tensile strength and yield stress of the extruded TMC was 157 MPa and 169 MPa, respectively, compared to those of extruded titanium materials with no CNT additive. Fractured surfaces of tensile specimens were analyzed by SEM, and the uniform distribution of CNTs and TiC particles, being effective for the dispersion strengthening, at the surface of the TMC were obviously observed. In the case of Mg-Al alloys, in-situ formation of Al2MgC2compounds at the interface between CNTs and Mg-matrix occurred and effective for the tensile transfer loading, and resulted in the increment of tensile strength of the composite material.

scholarly journals CNTs/TiC Reinforced Titanium Matrix Nanocomposites via Powder Metallurgy and Its Microstructural and Mechanical Properties

2008 ◽  
Vol 2008 ◽  
pp. 1-4 ◽  
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Hisashi Imai ◽  
Junko Umeda ◽  
Bunshi Fugetsu
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Pure Titanium ◽  
Multiwall Carbon Nanotubes ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Dispersion Strengthening ◽  
Titanium Matrix ◽  
Wet Process ◽  
Plasma Sintering

By using pure titanium powder coated with unbundled multiwall carbon nanotubes (MWCNTs) via wet process, powder metallurgy (P/M) titanium matrix composite (TMC) reinforced with the CNTs was prepared by spark plasma sintering (SPS) and subsequently hot extrusion process. The microstructure and mechanical properties of P/M pure titanium and reinforced with CNTs were evaluated. The distribution of CNTs and in situ formed titanium carbide (TiC) compounds during sintering was investigated by optical and scanning electron microscopy (SEM) equipped with EDS analyzer. The mechanical properties of TMC were significantly improved by the additive of CNTs. For example, when employing the pure titanium composite powder coated with CNTs of 0.35 mass%, the increase of tensile strength and yield stress of the extruded TMC was 157 MPa and 169 MPa, respectively, compared to those of extruded titanium materials with no CNT additive. Fractured surfaces of tensile specimens were analyzed by SEM, and the uniform distribution of CNTs and TiC particles, being effective for the dispersion strengthening, at the surface of the TMC were obviously observed.

Effect of Sidewall Fluorination on the Mechanical Properties of Catalytically Grown Multi-Wall Carbon Nanotubes

2011 ◽  
Vol 1284 ◽  
Author(s):  
Yogeeswaran Ganesan ◽  
Cheng Peng ◽  
Lijie Ci ◽  
Valery Khabashesku ◽  
Pulickel M. Ajayan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Tensile Strength ◽  
Electron Microscope ◽  
Tensile Testing ◽  
Load Bearing Capacity ◽  
Multi Wall Carbon Nanotubes ◽  
Pristine Mwnts ◽  
Scanning Electron

ABSTRACTWe report on the usage of a simple microfabricateddevice, that works in conjunction with a quantitative nanoindenter inside a scanning electron microscope (SEM), for the in situ quantitative tensile testing of individual sidewall fluorinated multi-wall carbon nanotubes (MWNTs). The stress vs. strain curves and the tensile strength values for five fluorinated specimens have been presented and compared to those of pristine MWNT specimens (data reported earlier). The fluorinated specimens were found to deform and fail in a brittle fashion similar to pristine MWNTs. However, sidewall fluorination was found to have considerably degraded the mechanical properties (tensile strength and load bearing capacity) of the MWNTs.

Microstructural and Mechanical Properties of Titanium Matrix Composites Reinforced with Nano Carbon Materials via Powder Metallurgy Process

2009 ◽  
Vol 618-619 ◽  
pp. 495-499 ◽  
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Junko Umeda ◽  
Hisashi Imai ◽  
Bunshi Fugetsu
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Pure Titanium ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Matrix Composites ◽  
Dispersion Strengthening ◽  
Titanium Matrix ◽  
Wet Process ◽  
Plasma Sintering

Powder metallurgy (P/M) titanium matrix composite (TMC) reinforced with multi-wall carbon nanotube (MWCNT) was prepared by spark plasma sintering (SPS) and hot extrusion process, where the powder surface was coated by un-bundled CNTs via wet process. The microstructure and mechanical properties of P/M pure titanium and reinforced with CNTs were evaluated. The distribution of CNTs and in-situ formed titanium carbide (TiC) compounds during sintering was investigated by optical and scanning electron microscopy (SEM) equipped with EDS analyser. The mechanical properties of TMC were significantly improved by adding a small amount of CNTs. For example, when employing the pure titanium composite powder coated with CNTs of 0.35 mass%, the increase of tensile strength and yield stress of the extruded TMC was 157 MPa and 169 MPa, respectively, compared to those of extruded titanium materials with no CNT additive. Fractured surfaces of specimens were analysed by SEM, and the uniform distribution of CNTs and TiC particles, being effective for the dispersion strengthening, at the surface of the TMC were obviously observed.

Microstructure and High Temperature Mechanical Properties of Mg-1Si-1Y Alloy

2012 ◽  
Vol 268-270 ◽  
pp. 365-370 ◽  
Author(s):  
Ying Ma ◽  
Zhong Ming Zhang ◽  
Zhen Lin Lv ◽  
Chun Jie Xu
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Elevated Temperature ◽  
Hot Extrusion ◽  
Extrusion Process ◽  
Dispersion Strengthening ◽  
X Ray ◽  
Fine Grained ◽  
High Temperature Mechanical Properties

Mg-1Si alloy doped with 1%Y was prepared by in-situ reaction synthesis. The effect of hot extrusion on the microstructure and elevated-temperature mechanical properties of the alloy was studied. The microstructures were analyzed by optical microscopy, scanning electron microscopy with energy dispersive X-ray spectroscopy and X-ray diffractometry. The results show that as-cast Mg-1Si-1Y alloy consists of dendritic α-Mg phase, eutectic needle-like Mg2Si phase and Mg24+xY5 phase precipitated from α-Mg, Mg2Si can be modified and refined by yttrium, and α-Mg grains can be refined by dynamic recrystallization occurred in hot extrusion process. The tensile strength and elongation of the alloy at ambient temperature are improved prominently by hot extrusion. The tensile strength and elongation of the extruded alloy is 185.3MPa and 24.3% at 120°C. The improved elevated-temperature properties of the alloy are ascribed to the fine-grained strengthening and dispersion strengthening from Mg2Si and Mg24+xY5 particles.

scholarly journals Characteristics of powder metallurgy pure titanium matrix composite reinforced with multi-wall carbon nanotubes

2009 ◽  
Vol 69 (7-8) ◽  
pp. 1077-1081 ◽  
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Hisashi Imai ◽  
Junko Umeda ◽  
Bunshi Fugetsu
Keyword(s):  
Carbon Nanotubes ◽  
Powder Metallurgy ◽  
Matrix Composite ◽  
Pure Titanium ◽  
Titanium Matrix ◽  
Titanium Matrix Composite ◽  
Multi Wall Carbon Nanotubes

scholarly journals Wide-Gap Brazing of K417G Alloy Assisted by In Situ Precipitation of M3B2 Boride Particles

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3140 ◽  
Author(s):  
Zhun Cheng ◽  
Xiaoqiang Li ◽  
Minai Zhang ◽  
Shengguan Qu ◽  
Huiyun Li
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Room Temperature ◽  
Distribution Characteristics ◽  
Powder Metallurgy Technique ◽  
Dispersion Strengthening ◽  
Eutectic Transformation ◽  
Wide Gap ◽  
Strength And Plasticity

In this study, K417G Ni-based superalloy with a 20-mm gap was successfully bonded at 1200 °C using powder metallurgy with a powder mixture. The results indicated that the microstructure and mechanical properties of the as-bonded alloy were highly dependent on the brazing time (15–45 min), mainly due to the precipitation and distribution characteristics of M3B2 boride particles. Specifically, alloy brazed for 30 min exhibited desirable mechanical properties, such as a high tensile ultimate strength of 971 MPa and an elongation at fracture of 6.5% at room temperature, exceeding the balance value (935 MPa) of the base metal. The excellent strength and plasticity were mainly due to coherent strengthening and dispersion strengthening of the in situ spherical and equiaxed M3B2 boride particles in the γ + γ′ matrix. In addition, the disappearance of dendrites and the homogenization of the microstructure are other factors that cannot be excluded. This powder metallurgy technique, which can avoid the eutectic transformation of traditional brazing, provides a new effective method for wide-gap repair of alloy materials.

scholarly journals Mechanical Characterization of Graphene Nanoplatelets-Reinforced Mg-3Sn Alloy Synthesized by Powder Metallurgy

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 62
Author(s):  
Pravir Kumar ◽  
Katerina Skotnicova ◽  
Ashis Mallick ◽  
Manoj Gupta ◽  
Tomas Cegan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Powder Metallurgy ◽  
Compressive Strain ◽  
Hot Extrusion ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Microstructural Characteristics

The present study investigated the effects of alloying and nano-reinforcement on the mechanical properties (microhardness, tensile strength, and compressive strength) of Mg-based alloys and composites. Pure Mg, Mg-3Sn alloy, and Mg-3Sn + 0.2 GNP alloy-nanocomposite were synthesized by powder metallurgy followed by hot extrusion. The microstructural characteristics of the bulk extruded samples were explored using X-ray diffraction, field-emission scanning electron microscopy, and optical microscopy and their mechanical properties were compared. The microhardness, tensile strength, and compressive strength of the Mg-3Sn alloy improved when compared to those of monolithic Mg sample and further improvements were displayed by Mg-3Sn + 0.2 GNP alloy-nanocomposite. No significant change in the compressive strain to failure was observed in both the alloy and the alloy-nanocomposite with respect to that of the pure Mg sample. However, an enhanced tensile strain to failure was displayed by both the alloy and the alloy-nanocomposite.

scholarly journals Mechanical Characterization of Graphene Nanoplatelets-Reinforced Mg-3Sn Alloy Synthesized by Powder Metallurgy

2020 ◽  
Author(s):  
Pravir Kumar ◽  
Katerina Skotnicova ◽  
Ashis Mallick ◽  
Manoj Gupta ◽  
Tomas Cegan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Powder Metallurgy ◽  
Compressive Strain ◽  
Hot Extrusion ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
Microstructural Characteristics

The present study investigated the effects of alloying and nano-reinforcement on the mechanical properties (microhardness, tensile strength, and compressive strength) of Mg-based alloys and composites. Pure Mg, Mg-3Sn alloy, and Mg-3Sn+0.2GNP alloy-nanocomposite were synthesized by powder metallurgy followed by hot extrusion. The microstructural characteristics of the bulk extruded samples were explored using X-ray diffraction, field-emission scanning electron microscopy, and optical microscopy and their mechanical properties were compared. The microhardness, tensile strength, and compressive strength of the Mg-3Sn alloy improved when compared to those of monolithic Mg sample and further improvements were displayed by Mg-3Sn+0.2GNP alloy-nanocomposite. No significant change in the compressive strain to failure was observed in both the alloy and the alloy-nanocomposite with respect to that of the pure Mg sample. However, an enhanced tensile strain to failure was displayed by both the alloy and the alloy-nanocomposite.

Improved dispersion of multi-wall carbon nanotubes in poly(butylene terephthalate) using benzimidazolium surfactants

e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Martino Colonna ◽  
Corrado Berti ◽  
Enrico Binassi ◽  
Maurizio Fiorini ◽  
Francesco Acquasanta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Carbon Nanotubes ◽  
Thermal Stability ◽  
In Situ Polymerization ◽  
Nucleation Process ◽  
Imidazolium Salt ◽  
Butylene Terephthalate ◽  
Multi Wall Carbon Nanotubes ◽  
Benzimidazolium Salt

AbstractMulti-wall carbon nanotubes/poly(butylene terephthalate) nanocomposites have been prepared by in-situ polymerization. Benzimidazolium tetrafluoroborate salts improve the dispersion of carbon nanotubes in the polymer matrix due to the formation of “π-cation” interactions of the imidazolium salt with the surface of the carbon nanotubes. An improved dispersion of the nanotubes in butanediol was also observed using the benzimidazolium salt. The presence of the compatibilization agent gives rise to improved thermo-mechanical properties and electrical conductivity for the nanocomposite. The presence of the nanotubes also consistently increases the thermal stability and enhances the nucleation process on PBT crystallization.

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