Good strength-plasticity compatibility in graphene nanoplatelets/Ti composites by strengthening the interface bonding via in-situ formed TiB whisker

2021 ◽  
Vol 47 (3) ◽  
pp. 4338-4343
Author(s):  
Liang Liu ◽  
Yunkai Li ◽  
Hongmei Zhang ◽  
Xingwang Cheng ◽  
Qunbo Fan ◽  
...  
2021 ◽  
Vol 21 (10) ◽  
pp. 5235-5240
Author(s):  
Hua-Hui Chen ◽  
Jing-Jing Cao ◽  
Hai-Ping Hong ◽  
Nan Zheng ◽  
Jie Ren ◽  
...  

In Situ transformed carbon fibers/Al2O3 ceramic matrix nanocomposites with Cao–MgO–SiO2 sintering agent were prepared by hot-pressed sintering technology in vacuum. In the sintering process, pre-oxidized polyacrylonitrile fibers (below named as pre-oxidized PAN fibers) were used as the precursors of In Situ transformed carbon fibers. The micro/nanostructure of composites and interface between In Situ transformed carbon fibers and matrix were investigated, as well as the properties of composites. The results showed that the composites could be sintered well at a relatively low temperature of 1650 °C. During the sintering, the precursors, pre-oxidized PAN fibers, were In Situ transformed into carbon fibers, and the In Situ transformed carbon fibers had the graphitelike structure along the fiber axial direction. The carbon atoms arrangement in the surface layer of the fiber was more orderly than the core. A typical diffraction peak of carbon fiber at 26°, which corresponded to the (002) crystal plane, was observed, and the inter-planar spacing was approximately 0.34 nm. The CaO–MgO–SiO2 sintering agent formed MgAl2O4 and CaAl2Si2O8 phases in the interface between In Situ transformed carbon fibers and matrix, therefore improving the interface bonding, and thereby modifying the mechanical properties of the composites.


2013 ◽  
Vol 765 ◽  
pp. 418-422 ◽  
Author(s):  
Ram Naresh Rai ◽  
A.K. Prasada Rao ◽  
G.L. Dutta ◽  
M. Chakraborty

The forming behaviour of in-situ Al-TiC composites was investigated by comparing microstructure and mechanical properties of as-cast, forged and rolled specimens. The microstructures of forged and rolled specimens reveal uniform distribution of the TiC particles, which are responsible for the enhancement of the tensile strength of the composite. The formed samples were found to be crack free. This feature is very likely to be due to good interface bonding of uniformly dispersed sub-micron size TiC particles with the Al matrix.


Molecules ◽  
2019 ◽  
Vol 24 (9) ◽  
pp. 1717 ◽  
Author(s):  
Zoi Terzopoulou ◽  
Evangelia Tarani ◽  
Nejib Kasmi ◽  
Lazaros Papadopoulos ◽  
Konstantinos Chrissafis ◽  
...  

Bio-based polyesters are a new class of materials that are expected to replace their fossil-based homologues in the near future. In this work, poly(propylene 2,5-furandicarboxylate) (PPF) nanocomposites with graphene nanoplatelets were prepared via the in-situ melt polycondensation method. The chemical structure of the resulting polymers was confirmed by 1H-NMR spectroscopy. Thermal stability, decomposition kinetics and the decomposition mechanism of the PPF nanocomposites were studied in detail. According to thermogravimetric analysis results, graphene nanoplatelets did nοt affect the thermal stability of PPF at levels of 0.5, 1.0 and 2.5 wt.%, but caused a slight increase in the activation energy values. Pyrolysis combined with gas chromatography and mass spectroscopy revealed that the decomposition mechanism of the polymer was not altered by the presence of graphene nanoplatelets but the extent of secondary homolytic degradation reactions was increased.


2015 ◽  
Vol 17 (4) ◽  
pp. 74-81 ◽  
Author(s):  
Sandra Paszkiewicz ◽  
Iwona Pawelec ◽  
Anna Szymczyk ◽  
Zbigniew Rosłaniec

Abstract This paper presents a comparative study on which type of platelets nanofiller, organic or inorganic, will affect the properties of thermoplastic elastomer matrix in the stronger manner. Therefore, poly(trimethylene terephthalate-block-poly(tetramethylene oxide) copolymer (PTT-PTMO) based nanocomposites with 0.5 wt.% of clay (MMT), graphene nanoplatelets (GNP) and graphene oxide (GO) have been prepared by in situ polymerization. The structure of the nanocomposites was characterized by transmission electron microscopy (TEM) in order to present good dispersion without large aggregates. It was indicated that PTT-PTMO/GNP composite shows the highest crystallization temperature. Unlike the addition of GNP and GO, the introduction of MMT does not have great effect on the glass transition temperature of PTMO-rich soft phase. An addition of all three types of nanoplatelets in the nanocomposites caused the enhancement in tensile modulus and yield stress. Additionally, the cyclic tensile tests showed that prepared nanocomposites have values of permanent set slightly higher than neat PTT-PTMO.


2013 ◽  
Vol 8 (1-2) ◽  
pp. 69-80 ◽  
Author(s):  
S. V. Pol’shchikov ◽  
P. M. Nedorezova ◽  
A. N. Klyamkina ◽  
V. G. Krashenninikov ◽  
A. M. Aladyshev ◽  
...  

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