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 ◽  
...  

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.

2020 ◽  
Vol 20 (7) ◽  
pp. 4253-4256
Author(s):  
Seong-Eun Kim ◽  
Jin-Kook Yoon ◽  
In-Jin Shon

Nb2O5 and Zr powders at a molar ratio of 1:2.5 were milled using a high-energy ball mill. The mixture powders produced Nb and ZrO2 nanopowders through a solid replacement reaction (Nb2O5+ 2.5Zr 2Nb + 2.5ZrO2). The synthesized nanopowders were consolidated via high-frequency induction heated sintering (HFIHS) within two min. The mechanical properties (hardness and fracture toughness) of nanostructured 2Nb–2.5ZrO2 composite were then evaluated. Both the hardness and fracture toughness of the 2Nb–2.5ZrO2 composite were higher than those of monolithic ZrO2.


2013 ◽  
Vol 39 (1) ◽  
pp. 585-591 ◽  
Author(s):  
Wonbaek Kim ◽  
Chang-Yul Suh ◽  
Ki-Min Roh ◽  
Jae-Won Lim ◽  
Sujeong Lee ◽  
...  

2010 ◽  
Vol 123-125 ◽  
pp. 209-212
Author(s):  
In Jin Shon ◽  
Hyun Su Kang ◽  
Soo Kyung Bae ◽  
In Yong Ko

A dense nanostructured 5NbSi2-SiC-Si3N4 composite was synthesized by the high-frequency induction-heated combustion synthesis (HFIHCS) method within 1 minute in one step from mechanically activated powders of 4NbN, NbC and 14Si. A highly dense 5NbSi2-SiC-Si3N4 composite with relative density of up to 98% was produced under the simultaneous application of a pressure of 80 MPa and the induced current. The average grain size and mechanical properties (hardness and fracture toughness) of the composite were investigated.


2012 ◽  
Vol 39 (6) ◽  
pp. 2339-2349 ◽  
Author(s):  
Wonbaek Kim ◽  
Seung-Mi Kwak ◽  
Chang-Yul Suh ◽  
Jae-Won Lim ◽  
Sung-Wook Cho ◽  
...  

2007 ◽  
Vol 124-126 ◽  
pp. 1153-1156 ◽  
Author(s):  
In Kyoon Jeong ◽  
Hwan Cheol Kim ◽  
Jung Mann Doh ◽  
Jin Kook Yoon ◽  
In Yong Ko ◽  
...  

Two methods, High-Frequency Induction-Heated Sintering (HFIHS) and Pulsed Current Activated Sintering (PCAS), were utilized to consolidate WC-8wt.%Ni hard materials. The demonstrated advantages of these processes are rapid densification to near theoretical density in a relatively short time and with insignificant change in grain size. The hardness, fracture toughness, and the relative density of the dense WC–8Ni composites produced by HFIHS and PCAS were investigated. And the effect of variation in particle size of WC powder on the sintering behavior and mechanical properties were investigated.


2020 ◽  
Vol 20 (7) ◽  
pp. 4436-4439
Author(s):  
Seong-Eun Kim ◽  
Jin-Kook Yoon ◽  
In-Jin Shon

The current concern about WC focuses on its low fracture toughness below the ductile-brittle transition temperature despite its many attractive properties. To improve its mechanical properties, the approach generally utilized has been the addition of a second phase to form composites and to make nanostructured materials. In this paper, graphene was evaluated as the reinforcing agent in WC ceramics using a novel sintering method (high-frequency induction heated sintering method). Highly dense nanostructured WC and WC-graphene composites were obtained within two min at 1550 °C. The effect of graphene on the grain size and the mechanical properties (hardness and fracture toughness) of WC-graphene composites was evaluated.


2019 ◽  
Vol 54 (6) ◽  
pp. 765-772 ◽  
Author(s):  
Ajay Kumar Vemulapalli ◽  
Rama Murty Raju Penmetsa ◽  
Ramanaiah Nallu ◽  
Rajesh Siriyala

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.


2010 ◽  
Vol 17 (02) ◽  
pp. 251-255
Author(s):  
DUCK-SOO KANG ◽  
KEE-DO WOO ◽  
EUI-PYO KWON ◽  
SANG-HYUK KIM ◽  
MIN-SEOK MOON ◽  
...  

Hard materials, in particular tungsten carbide ( WC ) hard material has been used in many industries as cutting tool and abrasive materials. For improving toughness, binders are added into carbide materials. The effect of Co as binder on the mechanical properties in the nanosized WC was discussed. The hardness and fracture toughness were also investigated using 30 kgf load Vickers indenter. The nanosized WC-8 , 10 and 12 vol.% Co composites were successfully fabricated without grain growth by high frequency induction heated sintering (HFIHS), which is the rapid sintering method, due to short sintering time 1140°C. The nanosized WC–Co composites fabricated by HFIHS have better mechanical properties than WC–Co composite fabricated by commercial sintering.


2021 ◽  
Author(s):  
Dalia Abulyazied ◽  
Asma Alturki ◽  
Rasha Youness ◽  
H. Abomostafa

Abstract In this work, a borosilicate glass sample (5SiO2-45B2O3-20Na2O-25CaO-5Ag2O) was added to nano-sized carbonated hydroxyapatite (CHA) powders with different contents up to 20 wt.% to improve the bioactivity, antibacterial effect, physical and mechanical properties of the resulting nanocomposites. Then, these samples were mixed, milled with a high-energy ball mill, sintered at 700°C and subjected to X-ray diffraction (XRD) technique, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) to examine their structure, chemical composition and microstructure, respectively. Furthermore, the physical and mechanical properties of the sintered nanocomposites were also measured. Moreover, the in vitro bioactivity of the prepared nanocomposites was examined with XRD and SEM. Additionally, the antibacterial behavior of these samples was tested against E. coli and S. aureus by the disc-diffusion method. The results obtained pointed out that the sample with the highest content of BG possessed the best bioactivity, antibacterial effect, physical and mechanical properties.


2021 ◽  
Author(s):  
Asma M. Alturki ◽  
Dalia E. Abulyazied ◽  
Mohammed Taha ◽  
H. M. Abomostafa ◽  
Rasha A. Youness

Abstract The aim of this work is to prepare nanocomposites with excellent bioactivity and appropriate mechanical properties. In this regard, the nanocomposites, with different contents of borosilicate glass (BG) and carbonated hydroxyapatite (CHA), were mixed and milled using a high-energy ball mill. Then, these milled powders were subjected to sintering at 750 ºC. In order to examine their phase composition, molecular structure and microstructure, X-ray diffraction (XRD) technique, Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM), respectively were used. Moreover, the DC electrical conductivity, and physical and mechanical properties of the prepared nanocomposites were also measured. In addition, the in vitro bioactivity of the sintered samples was evaluated using XRD and SEM. Unexpectedly; the results indicated that the successive increase in BG contents promoted the partial decomposition of CHA molecules at this lower sintering temperature. Also, it was responsible for the enhanced bioactivity behavior along with giving CHA better mechanical properties. However, the electrical conductivity of the examined samples exhibited an opposite trend where it decreased significantly with increasing BG content. According to the results obtained, the prepared samples are suitable for use in various biomedical applications.


Sign in / Sign up

Export Citation Format

Share Document