scholarly journals Investigation of Electromagnetic Pulse Compaction on Conducting Graphene/PEKK Composite Powder

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 636
Author(s):  
Quanbin Wang ◽  
Deli Jia ◽  
Xiaohan Pei ◽  
Xuelian Wu ◽  
Fan Xu ◽  
...  

Polymer-composite materials have the characteristics of light weight, high load, corrosion resistance, heat resistance, and high oil resistance. In particular, graphene composite has better electrical conductivity and mechanical performance. However, the raw materials of graphene composite are processed into semi-finished products, directly affecting their performance and service life. The electromagnetic pulse compaction was initially studied to get the product Graphene/PEKK composite powder. Simultaneously, spark plasma sintering was used to get the bars to determine the electrical conductivity of Graphene/PEKK composite. On the basis of this result, conducting Graphene/PEKK composite powder can be processed by electromagnetic pulse compaction. Finite element numerical analysis was used to obtain process parameters during the electromagnetic pulse compaction. The results show that discharge voltage and discharge capacitance influence on the magnetic force, which is a main moulding factor affecting stress, strain and density distribution on the specimen during electromagnetic pulse compaction in a few microseconds.

2014 ◽  
Vol 602-603 ◽  
pp. 451-456
Author(s):  
Jie Guang Song ◽  
Xiu Qin Wang ◽  
Fang Wang ◽  
Shi Bin Li ◽  
Gang Chang Ji

ZrB2, YAG and Al2O3 are widely applied because of some excellent performances, but ZrB2 is easily oxidized in the high-temperature air. To make the ZrB2 ceramics obtain better oxidation resistance, high-density ZrB2-YAG-Al2O3 ceramics were prepared. The influences of coated composite powders on the densification and the oxidation resistance of ZrB2-YAG-Al2O3 ceramics were investigated. The 80wt%ZrB2-YAG-Al2O3 multiphase ceramic materials from different composite raw materials with the spark plasma sintering technique were successfully prepared. The densification of ZrB2-YAG-Al2O3 ceramics with Al2O3-Y2O3 composite powder coated is easier than that of ZrB2-YAG-Al2O3 ceramics with YAG-Al2O3 powder mixed. The reaction temperature is lower than the 1100¡æ for synthesizing YAG powders from Al2O3-Y2O3 composite powders. The weight gain are increased with increased the oxidation temperature. B2O3 is reacted with Al2O3 to form Al18B4O33, Al18B4O33 is melted and coated on the surface of ceramics to form a protective layer for the oxidation resistance of ceramics at high temperature. The oxidation weight gain of ZrB2-YAG-Al2O3 ceramic with Al2O3-Y2O3 composite powder coated is lower than that of ZrB2-YAG-Al2O3 ceramic with YAG-Al2O3 powder mixed.


RSC Advances ◽  
2015 ◽  
Vol 5 (98) ◽  
pp. 80428-80433 ◽  
Author(s):  
Weiping Li ◽  
Delong Li ◽  
Qiang Fu ◽  
Chunxu Pan

In this paper, we report an electrical conductivity enhanced copper/graphene composite based on high-quality graphene (HQG) via processes involving graphene-coated copper powders through ball milling, and subsequent spark plasma sintering (SPS).


2013 ◽  
Vol 804 ◽  
pp. 42-46
Author(s):  
Jie Guang Song ◽  
Ming Han Xu ◽  
Xiu Qin Wang ◽  
Shi Bin Li ◽  
Gang Chang Ji

ZrB2 has some excellent physical performance and chemical stability, it has been widely applied in a lot of fields. In order to improve disadvantages of ZrB2 that the sintering densification of ZrB2 is too difficult, and it is easy oxidized at high temperature, in this paper, the sintering character of coated A12O3-Y2O3/ZrB2 composite powder materials via spark plasma sintering were investigated. Al2O3-Y2O3/ZrB2 composite powders were prepared by a co-precipitation methods. When the pH is 9, the encapsulted structure of A1(OH)3-Y(OH)3/ZrB2 composite powders is the best. By analyzing the ZrB2 surface status with TEM, the A12O3-Y2O3/ZrB2 composite powders were prepared under the calcining conditions of 600°C¡æ in argon. The high density ZrB2-YAG multi-phase ceramics are prepared via spark splama sintering, which indicate the raw materials adding A12O3-Y2O3 help for the densification of ZrB2 ceramics.


Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1150
Author(s):  
Nicolás A. Ulloa-Castillo ◽  
Roberto Hernández-Maya ◽  
Jorge Islas-Urbano ◽  
Oscar Martínez-Romero ◽  
Emmanuel Segura-Cárdenas ◽  
...  

This article focuses on exploring how the electrical conductivity and densification properties of metallic samples made from aluminum (Al) powders reinforced with 0.5 wt % concentration of multi-walled carbon nanotubes (MWCNTs) and consolidated through spark plasma sintering (SPS) process are affected by the carbon nanotubes dispersion and the Al particles morphology. Experimental characterization tests performed by scanning electron microscopy (SEM) and by energy dispersive spectroscopy (EDS) show that the MWCNTs were uniformly ball-milled and dispersed in the Al surface particles, and undesirable phases were not observed in X-ray diffraction measurements. Furthermore, high densification parts and an improvement of about 40% in the electrical conductivity values were confirmed via experimental tests performed on the produced sintered samples. These results elucidate that modifying the powder morphology using the ball-milling technique to bond carbon nanotubes into the Al surface particles aids the ability to obtain highly dense parts with increasing electrical conductivity properties.


2006 ◽  
Vol 118 ◽  
pp. 661-665 ◽  
Author(s):  
Dae Hwan Kwon ◽  
Thuy Dang Nguyen ◽  
Pyuck Pa Choi ◽  
Ji Soon Kim ◽  
Young Soon Kwon

The microstructure and properties of Cu-TiB2 composites produced by high-energy ball-milling of TiB2 powders and spark-plasma sintering (SPS) were investigated. TiB2 powders were mechanically milled at a rotation speed of 1000rpm for short time in Ar atmosphere, using a planetary ball mill. To produce Cu-xTiB2 composites( x = 2.5, 5, 7.5 and 10wt.% ), the raw and milled TiB2 powders were mixed with Cu powders by means of a turbular mixer, respectively. Sintering of mixed powders was carried out in a SPS facility under vacuum. High-energy ball-milling resulted in refinement of TiB2 particles. XRD patterns of milled TiB2 powders indicated broader TiB2 peaks with decreased intensities. After sintering at 950 for 5min using the raw and milled TiB2 mixture powders, the sintered density decreased with increasing TiB2 content regardless of milling of TiB2. In the case of raw TiB2, hardness rapidly increased from 4 to 44 HRB with increasing TiB2 content. The electrical conductivity changed from 95.5 to 80.7 %IACS. For mixtures of Cu powders with milled TiB2 powders, hardness increased from 38 to 67 HRB as TiB2 content increased, while the electrical conductivity varied from 88% to 51 % IACS. When compared to compacts sintered with raw and milled TiB2 powders, the electrical conductivity of specimens with raw TiB2 powder was higher than that of specimens with milled TiB2 powder, while hardness was slightly lower.


2007 ◽  
Vol 534-536 ◽  
pp. 1489-1492 ◽  
Author(s):  
Dae Hwan Kwon ◽  
Jong Won Kum ◽  
Thuy Dang Nguyen ◽  
Dina V. Dudina ◽  
Pyuck Pa Choi ◽  
...  

Dispersion-strengthened copper with TiB2 was produced by ball-milling and spark plasma sintering (SPS).Ball-milling was performed at a rotation speed of 300rpm for 30 and 60min in Ar atmosphere by using a planetary ball mill (AGO-2). Spark-plasma sintering was carried out at 650°C for 5min under vacuum after mechanical alloying. The hardness of the specimens sintered using powder ball milled for 60min at 300rpm increased from 16.0 to 61.8 HRB than that of specimen using powder mixed with a turbular mixer, while the electrical conductivity varied from 93.40% to 83.34%IACS. In the case of milled powder, hardness increased as milling time increased, while the electrical conductivity decreased. On the other hand, hardness decreased with increasing sintering temperature, but the electrical conductiviey increased slightly


2020 ◽  
Author(s):  
Ryszard Skulski ◽  
Dariusz Bochenek ◽  
Dagmara Brzezińska ◽  
Leszek Stobinski ◽  
Przemysław Niemiec ◽  
...  

Abstract In this paper there is described the technology of obtaining and results of investigations of microstructure, XRD, SEM, main dielectric properties, electrical conductivity measurements and P-E hysteresis loops of Ba0.6Pb0.4TiO3/graphene oxide composite (abbr. BPT/GO). In the final step of technology, the samples have been sintered using the Spark Plasma Sintering (SPS) method. Diffraction patterns of BPT/GO composite exhibit lines which can be related with perovskite structure, as well as reveal additional lines that can be derived from the initial component oxides. Investigations of electrical conductivity suggest that the PTCR effect occurs at temperatures up to about 120°C. Dielectric hysteresis loops below 90°C are wide and typical for materials with rather high electrical conductivity. The hysteresis loop obtained at 120°C is more typical for ferroelectrics. The obtained material is interesting, however it is probably possible to find better conditions of obtaining it and/or a better composition.


2021 ◽  
Vol 1016 ◽  
pp. 1770-1777
Author(s):  
Liu Zhu ◽  
Jin Fang Wang ◽  
Zhi Biao Tu ◽  
Na Xue ◽  
Wei Wei Li

The WC composite powder was synthesized by a new specific chemical activation technique. A large number of lattice defects such as surface humps, dislocations and stacking fault exist in the surface of the WC powder after chemical activation technique. By using such activated WC powder, the binderless WC cemented carbide with high density (15.54 g/cm3), super hardness (average 26.29 GPa) and excellent fracture toughness (8.9 MPa.m1/2) can be fabricated by SPS at 1700 °C and 50 MPa pressure. The improvement in density, hardness and fracture toughness are respectively 4.5%, 15.3% and 17.1% compared to when using the original WC powder. This improvement is because microscopic defects on the surface of the WC powder can greatly improve surface free energy of the powder, which improves the sintering activity and reduces the sintering temperature of the WC powder.


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