Evaluation of the Mechanical Properties of Carbon Nanotube (CNT) Reinforced Aluminum (6061) Composites Using Closed Die Forging

2020 ◽  
Vol 843 ◽  
pp. 33-38
Author(s):  
J.S.Suresh Babu ◽  
Jun Park ◽  
Chung Gil Kang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Compressive Strength ◽  
Large Deformations ◽  
High Energy ◽  
Cold Upsetting ◽  
Die Forging ◽  
Closed Die Forging ◽  
Energy Ball ◽  
Upsetting Test

In this study, the closed die forging of aluminium based compoistes reinfoced with CNTs (1vol% and 3vol%) were investigated. Initially, the composites were fabricated using high energy ball milling followed by compaction and sintering. The microstructural results showed that finer grain size and homogeneous dispersion of CNTs were obtained. Composites with up to 97% densification were produced when fine open porosities were removed by closed die forging. The results imply that the hardness and compressive strength of composites with 3vol.% of CNTs has improved without any deterioration. In addition, workability behaviors of composites were investigated by cold upsetting test. For that pore reopening test was performed to confirm the closure of micro-pores after the closed die forged, and to further analyze the densification of the composites. Typical cases, as the pores were not re-opened even after increasing the strain, additional forming is possible up to large deformations.

Effect of Sintering Temperature on Microstructure and Mechanical Properties of WC-16TiC-xTaC-9Co Cemented Carbides

2012 ◽  
Vol 268-270 ◽  
pp. 340-343
Author(s):  
Chong Cai Zhang ◽  
Quan Wang
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Sintering Temperature ◽  
Rupture Strength ◽  
High Energy ◽  
Cemented Carbides ◽  
Average Grain Size ◽  
Comprehensive Performance ◽  
Energy Ball ◽  
Average Size

In this paper, the WC-16TiC-xTaC-9Co and Co are mixed together preparing for WC, (W, Ti, Ta) C. By high-energy ball milling, the powder is cold isostatic pressed and vacuum sintered by 1410°C, 1430°Cand 1450°C.The physical properties and the micrographs of samples are detected. The main conclusions are as following: sintered samples have the best comprehensive performance at 1450°C, the density of the sample is 99.7% and the actual density is 10.91g/cm3. The hardness is 92.8 HRA and the transverse rupture strength (TRS) is 1100MPa. The grain size grows up obviously with the high temperature. The average grain size of WC is 0.7μm and the average size of (W, Ti, Ta)C is 3μm.

scholarly journals Nanocrystalline Materials: Synthesis, Characterization, Properties, and Applications

Crystals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1317
Author(s):  
Amanendra K. Kushwaha ◽  
Merbin John ◽  
Manoranjan Misra ◽  
Pradeep L. Menezes
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Chemical Vapor ◽  
Chemical Precipitation ◽  
High Energy ◽  
Synthesis Methods ◽  
Materials Synthesis ◽  
Current State ◽  
Superior Mechanical Properties ◽  
Energy Ball

Nanostructuring is a commonly employed method of obtaining superior mechanical properties in metals and alloys. Compared to conventional polycrystalline counterparts, nanostructuring can provide remarkable improvements in yield strength, toughness, fatigue life, corrosion resistance, and hardness, which is attributed to the nano grain size. In this review paper, the current state-of-the-art of synthesis methods of nanocrystalline (NC) materials such as rapid solidification, chemical precipitation, chemical vapor deposition, and mechanical alloying, including high-energy ball milling (HEBM) and cryomilling was elucidated. More specifically, the effect of various process parameters on mechanical properties and microstructural features were explained for a broad range of engineering materials. This study also explains the mechanism of grain strengthening using the Hall-Petch relation and illustrates the effects of post-processing on the grain size and subsequently their properties. This review also reports the applications, challenges, and future scope for the NC materials.

Rapid Consolidation of Nanocrystalline Al2O3 Reinforced Cr Composite from Mechanically Alloyed Powders by Pulsed Current Activated Sintering

2010 ◽  
Vol 123-125 ◽  
pp. 197-200 ◽  
Author(s):  
In Jin Shon ◽  
Hyun Su Kang ◽  
Dong Mok Lee ◽  
Kwon Il Na ◽  
In Yong Ko
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
High Energy ◽  
Pulsed Current ◽  
Mechanically Alloyed ◽  
Activated Sintering ◽  
Simultaneous Application ◽  
Al2o3 Composite ◽  
Average Grain Size ◽  
Energy Ball

Nanopowders of Cr and Al2O3 was fabricated from CrO3 and 2Al by high energy ball milling. Dense nanocrystalline Cr-Al2O3 composite was consolidated by pulsed current activated sintering (PCAS) method within 1 min from mechanically alloyed powders. Highly dense Cr-Al2O3 with relative density of up to 99% was produced under simultaneous application of a 80 MPa pressure and the pulsed current. The average grain size and mechanical properties of the composite were investigated.

Preparation of WC-5TiC-10Co Nanometer Powder and Performance Study of Sintering Samples

2012 ◽  
Vol 465 ◽  
pp. 220-223 ◽  
Author(s):  
Chong Cai Zhang ◽  
Quan Wang ◽  
Qun Qun Yuan ◽  
Yong Fei Yang ◽  
Xiao Lan Yi
Keyword(s):  
Grain Size ◽  
Compressive Strength ◽  
Ball Milling ◽  
High Energy ◽  
Cemented Carbides ◽  
Performance Study ◽  
Vacuum Sintering ◽  
Average Grain Size ◽  
Energy Ball ◽  
And Performance

In this paper, the WC-5TiC-10 Co mixture mixed by WC2.96μm, (Ti, W)C 2.52μm and Co2.38μm and prepared by high-energy ball milling. The result shows: After 60h’s ball milling the powder began to reunite more and more as the time extended . The average grain size of powder is 50 nm after144h. After 1300°C~1400°C vacuum-sintering the hardness of the sample is 94.8 ~ 95.4HRA. 4.2 ~ 5.2 HRA higher than the traditional cemented carbides with the same composition. After 1400°C vacuum-sintering the compressive strength and flexural strength of cemented carbides is 2060 MPa and 1200 MPa. Slightly less than the traditional cemented carbides with the same composition.

HAp/TiO2 nanocomposites: Influence of TiO2 on microstructure and mechanical properties

2019 ◽  
Vol 54 (6) ◽  
pp. 765-772 ◽  
Author(s):  
Ajay Kumar Vemulapalli ◽  
Rama Murty Raju Penmetsa ◽  
Ramanaiah Nallu ◽  
Rajesh Siriyala
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Grain Size ◽  
Flexural Strength ◽  
Bone Growth ◽  
High Energy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Microstructure And Mechanical Properties ◽  
Energy Ball

Hydroxyapatite is a very attractive material for artificial implants and human tissue restorations because they accelerate bone growth around the implant. The hydroxyapatite nanocomposites (HAp/TiO2) were produced by using high energy ball milling. X-ray diffraction studies revealed the formation of HAp and TiO2 composites. Cubic-like crystals with boundary morphologies were observed; it was also found that the grain size gradually increased with the increase in TiO2 content. It was found that the mechanical properties (hardness, Young's modulus, fracture toughness, flexural strength, and compression strength)of the composites significantly improved with the addition of TiO2, which was sintered at 1200℃. These properties were then also correlated with the microstructure of the composites. This paper investigates the effect of titania (TiO2 = 0, 5, 10, 15, 20, and 25 wt%) addition on the microstructure and mechanical properties of hydroxyapatite (Ca10(PO4)6(OH)2) nanocomposites.

scholarly journals Mechanochemical Synthesis and Rapid Consolidation of Nanocrystalline 3NiAl-Al2O3Composites

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
In-Jin Shon ◽  
In-Yong Ko ◽  
Seung-Hoon Jo ◽  
Jung-Mann Doh ◽  
Jin-Kook Yoon ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Mechanochemical Synthesis ◽  
High Frequency ◽  
Nanocrystalline Materials ◽  
Physical And Mechanical Properties ◽  
High Energy ◽  
Reinforced Composite ◽  
Energy Ball ◽  
High Frequency Induction

Nanopowders of 3NiAl and Al2O3were synthesized from 3NiO and 5Al powders by high-energy ball milling. Nanocrystalline Al2O3reinforced composite was consolidated by high-frequency induction-heated sintering within 3 minutes from mechanochemically synthesized powders of Al2O3and 3NiAl. The advantage of this process is that it allows very quick densification to near theoretical density and inhibition grain growth. Nanocrystalline materials have received much attention as advanced engineering materials with improved physical and mechanical properties. The relative density of the composite was 97%. The average Vickers hardness and fracture toughness values obtained were 804 kg/mm2and 7.5 MPa⋅m1/2, respectively.

scholarly journals Influence of mechanical activation of AL2O3 on synthesis of magnesium aluminate spinel

2004 ◽  
Vol 36 (2) ◽  
pp. 73-79 ◽  
Author(s):  
Zhang Zhihui ◽  
LI. Nan
Keyword(s):  
Grain Size ◽  
Mechanical Activation ◽  
Bulk Density ◽  
Milling Time ◽  
High Energy ◽  
Magnesium Aluminate ◽  
Reaction Sintering ◽  
Air Atmosphere ◽  
Energy Ball ◽  
Analytical Reagent

Magnesium aluminate (MA) spinel is synthesized by reaction sintering from alumina and magnesia. The effects of mechanical activation of Al2O3 on reaction sintering were investigated. Non-milled a - Al2O3 and a - Al2O3 high-energy ball milled for 12h, 24h and 36h were mixed with a MgO analytical reagent according to the stoichiometric MA ratio, respectively and pressed into billets with diameters of 20mm and height of 15mm. The green-body billets were then sintered at high temperature in an air atmosphere. The results show that bulk density, relative content of MA and grain size of MA increase with increasing high-energy ball milling time of Al2O3. However prolonged milling time over 24h has a small beneficial effect on the densification of MA. Bulk density and grain size of a sample of a- Al2O3 milled for 24h are 3.30g/cm3 and 4-5 mm, respectively.

Microhardness Enhancement in Fully Dense Fe-Based Nanophase Metallic Alloys

1995 ◽  
Vol 400 ◽  
Author(s):  
L. He ◽  
E. Ma
Keyword(s):  
Grain Size ◽  
High Energy ◽  
Metallic Alloys ◽  
Full Density ◽  
Strengthening Effect ◽  
Two Phase ◽  
Grain Sizes ◽  
Sinter Forging ◽  
Interphase Boundaries ◽  
Energy Ball

AbstractNano-grained Fe-29Al-2Cr intermetallic and Fe-Cu two-phase composites have been consolidated to full density from powders produced by high-energy ball milling, using a sinter forging procedure developed recently in our laboratory. Grain sizes remained within nanophase range (<100 nm) after consolidation. Microhardness tests of Fe-29Al-2Cr samples consolidated to different density levels indicate a significant strengthening effect due to nanoscale grain size and a monotonic microhardness increase with decreasing residual porosity. Fully dense Fe-Cu composites exhibit enhanced microhardness as compared with rule-of-mixtures predictions, which may be attributable to interface strengthening at fcc-bcc interphase boundaries.

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