Conductive enhancement of copper/graphene composites based on high-quality graphene

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).

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


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.


2013 ◽  
Vol 1513 ◽  
Author(s):  
R.C. Picu ◽  
J.J. Gracio ◽  
G.T. Vincze ◽  
N. Mathew ◽  
T. Schubert ◽  
...  

ABSTRACTIn this work Al-SiC nanocomposites were prepared by high energy ball milling followed by spark plasma sintering of the powder. For this purpose Al micro-powder was mixed with 50 nm diameter SiC nanoparticles. The final composites had grains of approximately 100 nm dimensions, with SiC particles located mostly at grain boundaries. To characterize their mechanical behavior, uniaxial compression, micro- and nano-indentation were performed. Materials with 1vol% SiC as well as nanocrystalline Al produced by the same means with the composite were processed, tested and compared. AA1050 was also considered for reference. It was concluded that the yield stress of the nanocomposite with 1 vol% SiC is 10 times larger than that of regular pure Al (AA1050). Nanocrystalline Al without SiC and processed by the same method has a yield stress 7 times larger than AA1050. Therefore, the largest increase is due to the formation of nanograins, with the SiC particles’ role being primarily that of stabilizing the grains. This was demonstrated by performing annealing experiments at 150°C and 250°C for 2h, in separate experiments.


Author(s):  
Enrique Martínez-Franco ◽  
Ming Li ◽  
Ricardo Cuenca Álvarez ◽  
Jesús González Hernández ◽  
Chao Ma ◽  
...  

Metal matrix nanocomposites (MMNCs) are anticipated to offer significantly better performance than existing superalloys. Nickel/alumina nanocomposite samples were fabricated with a powder metallurgy method, combining high-energy ball milling (HEBM) and spark plasma sintering (SPS). The objective of this research is to determine the effect of alumina nanoparticle fraction and HEBM parameters on the powder preparation and sintering processes, and resultant microstructure and properties. Nickel-based powders containing various fractions (1, 5 and 15 vol.%) alumina nanoparticles were prepared by HEBM. The initial particle sizes were 44 μm and 50 nm for nickel and alumina, respectively. The milling process was conducted by starting with mixing at 250 rpm for 5 min, followed by cycling operation at high and low speeds (1200 rpm for 4 min and 150 rpm for 1 min). Samples at different milling times (30, 60, 90 and 120 min) of each composition were obtained. Scanning electron microscopy (SEM) was used to evaluate the dispersion of nanoparticles in the powders at different milling times. SPS technique was used for consolidation of the prepared powders. SEM images showed that alumina nanoparticles are homogeneously dispersed in the metal matrix in the sample containing 15 vol.% alumina. Hardness measurements in cross sections of SPSed samples showed higher values for Ni/Al2O3 MMNC compared to pure Ni.


Sign in / Sign up

Export Citation Format

Share Document