Multi-Walled Carbon Nanotubes Reinforced Titanium Composites via Powder Metallurgy Process

2012 ◽  
Vol 520 ◽  
pp. 261-268 ◽  
Author(s):  
Katsuyoshi Kondoh ◽  
Thotsaphon Threrujirapapong ◽  
Sun Bin ◽  
Hisashi Imai ◽  
Shu Feng Li ◽  
...  

Un-bundled multi-walled carbon nanotubes (MWCNTs) were coated on titanium powder surface by using zwitterionic surfactant solution and mixing process, and their CNT/Ti composite powders were consolidated into full-dense materials by spark plasma sintering and the following hot extrusion process in solid-state. Wrought titanium powder metallurgy (PM) composites containing CNTs revealed extreme increment of yield stress and tensile strength of 85% and 50%, respectively, compared to conventional PM titanium with no reinforcement, while they had enough high ductility. The mechanical improvement was mainly due to dispersion strengthening effect of CNTs and in-situ formed TiC fine particles and a small mount of carbon solid solution into Ti matrix. In addition, the control of grain growth was promoted by TiC dispersoids during SPS, and contributed to their strengthening behavior. Furthermore, high-temperature tensile strength less than 673K of PM pure titanium materials was also obviously improved by the pinning effect of TiC particles dispersed at grain boundaries. In this paper, microstructural and mechanical properties of powder metallurgy titanium composites would be introduced in detail.

2018 ◽  
Vol 50 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Van Trinh ◽  
Van Luan ◽  
Doan Phuong ◽  
Phan Minh

In this study, we report the processing, microstructure, and microhardness of aluminum-copper composites reinforced with multi-walled carbon nanotubes (CNTs). Composite powders were prepared by a high energy ball (HEB) milling process then consolidated by vacuum sintering and hot isostatic pressing (HIP) techniques. The specimens show a uniform dispersion of CNTs in the Al-Cu matrix with CNT content up to 1 wt.% and a cluster formation observed with higher CNT content of 1.5 wt.%. The specimens have a relative density of 92 % to 95 % for composites sintered by vacuum sintering and 93 % to 96 % for composites sintered by HIP. Microhardness of specimens increases with increasing CNT content up to 1_wt% and then decreases due to the formation of CNT clusters. Microhardness is enhanced both by the dispersion strengthening effect of CNTs and by precipitation hardening of Al-Cu matrix.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fahad Saleem Ahmed Khan ◽  
N. M. Mubarak ◽  
Mohammad Khalid ◽  
Rashmi Walvekar ◽  
E. C. Abdullah ◽  
...  

AbstractModified multi-walled carbon nanotubes (f-MWCNTs) and hydroxyapatite nanorods (n-HA) were reinforced into polypropylene (PP) with the support of a melt compounding approach. Varying composition of f-MWCNTs (0.1–0.3 wt.%) and nHA (15–20 wt.%) were reinforced into PP, to obtain biocomposites of different compositions. The morphology, thermal and mechanical characteristics of PP/n-HA/f-MWCNTs were observed. Tensile studies reflected that the addition of f-MWCNTs is advantageous in improving the tensile strength of PP/n-HA nanocomposites but decreases its Young’s modulus significantly. Based on the thermal study, the f-MWCNTs and n-HA were known to be adequate to enhance PP’s thermal and dimensional stability. Furthermore, MTT studies proved that PP/n-HA/f-MWCNTs are biocompatible. Consequently, f-MWCNTs and n-HA reinforced into PP may be a promising nanocomposite in orthopedics industry applications such as the human subchondral bone i.e. patella and cartilage and fabricating certain light-loaded implants.


Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Jung-Eun Park ◽  
Yong-Seok Jang ◽  
Tae-Sung Bae ◽  
Min-Ho Lee

Multi walled carbon nanotubes-hydroxyapatite (MWCNTs-HA) with various contents of MWCNTs was synthesized using the sol-gel method. MWCNTs-HA composites were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). HA particles were generated on the surface of MWCNT. Produced MWCNTs-HA nanocomposites were coated on pure titanium (PT). Characteristic of the titanium coated MWCNTs-HA was evaluated by field-emission scanning electron microscopy (FE-SEM) and XRD. The results show that the titanium surface was covered with MWCNTs-HA nanoparticles and MWCNTs help form the crystalized hydroxyapatite. Furthermore, the MWCNTs-HA coated titanium was investigated for in vitro cellular responses. Cell proliferation and differentiation were improved on the surface of MWCNT-HA coated titanium.


2017 ◽  
Vol 51 (12) ◽  
pp. 1693-1701 ◽  
Author(s):  
EA Zakharychev ◽  
EN Razov ◽  
Yu D Semchikov ◽  
NS Zakharycheva ◽  
MA Kabina

This paper investigates the structure, length, and percentage of functional groups of multi-walled carbon nanotubes (CNT) depending on the time taken for functionalization in HNO3 and H2SO4 mixture. The carbon nanotube content and influence of functionalization time on mechanical properties of polymer composite materials based on epoxy matrix are studied. The extreme dependencies of mechanical properties of carbon nanotube functionalization time of polymer composites were established. The rise in tensile strength of obtained composites reaches 102% and elastic modulus reaches 227% as compared to that of unfilled polymer. The composites exhibited best mechanical properties by including carbon nanotube with 0.5 h functionalization time.


2008 ◽  
Vol 41-42 ◽  
pp. 27-32 ◽  
Author(s):  
Chun Sheng Lu

Two available strength data sets of single-walled and multi-walled carbon nanotubes are analysed, and the effects of sample sizes on their tensile strengths are investigated. A minimum information criterion is applied to determine the optimal strength distribution. The results show that, in contrast to a two-parameter Weibull distribution, lognormal distribution seems to be a more suitable choice. A simple extrapolation of classical Weibull statistics to nanoscales may result in overestimation on the tensile strength of carbon nanotubes.


2015 ◽  
Vol 719-720 ◽  
pp. 141-144
Author(s):  
Chen Chi M. Ma ◽  
Sheng Tsung Hsiao ◽  
Wei Hao Liao ◽  
Shin Ming Li ◽  
Yu Sheng Wang ◽  
...  

This study proposed a method to improve the mechanical properties and thermal conductivity of epoxy composites by incorporating multi-walled carbon nanotubes (MWCNTs) and multi-graphene platelets (MGPs) hybrid materials. The MWCNT can bridge adjacent MGPs and inhibit their aggregation effectively, leading to an increased contact surface area between MGP/MWCNT hybrid materials and epoxy matrix. From observing the fractured surface of composite by scanning electron microscope, MWCNT/MGP hybrid materials exhibited better compatibility than individual MWCNT and MGP did.The tensile strength of GD400-MWCNT/MGP/epoxy composites was 35.4% higher than that of epoxy, compared to only a 0.9% increase in tensile strength for MGP/epoxy composites. Thermal conductivity enhanced by 146.9% through incorporating MWCNT/MGP hybrid materials and 23.9% for MGP fillers, compared to non-derivatised epoxy.


2006 ◽  
Vol 313 ◽  
pp. 145-150 ◽  
Author(s):  
Jing Wang ◽  
Hua Min Kou ◽  
Yu Bai Pan ◽  
Jing Kun Guo

Carbon nanotube-mullite (Al2O3/SiO2=3/2) composites have been prepared by hot-pressing the corresponding composite powders, in which the multi-walled carbon nanotubes(1~10 vol%) are homogeneously dispersed between the mullite grains. The microstructure of the specimens has been studied and discussed in relation to the properties of the matrix, the bending strength and the fracture toughness, the dielectric constant and the dissipative factor. Carbon nanotube-mullite composites are potential electromagnetic wave absorbers owing to the percolation of the carbon nanotubes.


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