scholarly journals A Study on Ni-Fe Ball Milled Spark Plasma Sintered Sample

2011 ◽  
Vol 8 (1) ◽  
pp. 157-164
Author(s):  
A. Rajadurai ◽  
Gouthama Gouthama ◽  
T Ashokkumar
Keyword(s):  
Ball Milling ◽  
Sintered Sample ◽  
High Energy ◽  
Milling Process ◽  
Average Particle ◽  
Particle Sizes ◽  
Milled Sample ◽  
Spark Plasma ◽  
Energy Ball ◽  
Temperature And Pressure

Mechanical alloying through high energy ball milling was used to produce 40wt.%Ni-Fe alloy powder of average particle sizes 80 μm and 25 μm respectively. High Energy Planetary ball milling at room temperature was performed for various time durations of 16, 32 and 64 hours. Sintering was carried on DR.SINTER.LABTM (SPS 515S) machine. Samples were sintered at constant temperature of 650°C and pressure of 30 MPa for all samples. This study exhibits in same alloy, but increases of milling hours, the densification of the sintered samples decreases and also porosity of the sample increases. This may be due to the reasons of increases in the surface area of the milled nanopowder (ie. Reduction of particle size), low green body density of long milling powders by agglomeration of powders and oxidation of powders during a milling process. However, this study revealed that in the same alloy with increasing milling hours, required more temperature and pressure for perfect densification. Densification of 85.4 % was achieved in 16 hours milled sample.

Nanocrystalline Diamond Particles Prepared by High-Energy Ball Milling Method

2013 ◽  
Vol 284-287 ◽  
pp. 168-172 ◽  
Author(s):  
Chii Ruey Lin ◽  
Da Hua Wei ◽  
Minh Khoa Ben Dao ◽  
Ren Jei Chung ◽  
Ming Hong Chang
Keyword(s):  
Ball Milling ◽  
Average Particle Size ◽  
Diamond Powder ◽  
High Energy ◽  
Milling Process ◽  
High Energy Ball Milling ◽  
Acid Mixture ◽  
Average Particle ◽  
X Ray ◽  
Energy Ball

In this present work, nanodiamond (ND) particles were successfully prepared from commercial micron diamond powder at room temperature by high energy ball milling process using an oscillatory mill (SPEX8000). The size reduction and structural evolutions of the milled samples were investigated as a function of the milling time by means of X-ray diffraction, and field emission scanning electron microscopy. The line broadening technique was used to determine the crystallite size and lattice strain. After 40 h of milling, obtained ND particles possessed uniform shape and 25 nm of average particle size. Also, energy dispersive X-ray results revealed the high purity of ND and demonstrated that the purification process using harsh acid mixture were effective to remove metal and non-diamond carbon impurities produced in milling stage. All results propose a scalable method to preparation ND particles as well as nanocrystalline materials.

Effect of High-Energy Ball Milling of ZrB2 Powder on the Microstructure and Mechanical Properties of ZrB2-SiC Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 723-728
Author(s):  
Qi Long Guo ◽  
Jun Guo Li ◽  
Qiang Shen ◽  
Lian Meng Zhang
Keyword(s):  
Ball Milling ◽  
Average Particle Size ◽  
Sintered Sample ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Sample Introduction ◽  
Second Phase ◽  
Average Particle ◽  
Sic Ceramics ◽  
Energy Ball

The sinterability of ZrB2-20vol.% SiC ceramics by high-energy ball milling as well as introduction of Zr and Al as sintering additives. Densification process and microstructure of ZrB2-SiC ceramics were investigated. After high-energy ball milling, the average particle size decreased to about 500 nm-2 μm, and ZrB2-SiC powder can be sintered to 98.92% theoretical density at 1800 °C, but a trace of amount of oxidation (ZrO2) were detected in sintered sample. Introduction of Zr, Al and C combined with high-energy ball milling enhanced the densification of ZrB2-SiC ceramics and reduced the particle sizes, and the relative density of obtained ceramic reached up to 99.49% at 1800 °C. The additions of Zr, Al and C can remove the oxide impurities of the surface of ZrB2 particles and form a reaction between oxide impurities. The fracture toughness increased of the 40% when ZrB2 powders were milled by high-energy ball milling, and increased to 4.77±0.18 MPa•m1/2. However, the attrition-milled composites had lower hardness and Young’s modulus, which was attributed to the presence of a second phase in the grain boundaries.

Effect of High-Energy Ball-Milling and TiB2 Content on Microstructures and Properties of Cu-TiB2 Composites Sintered by SPS

2006 ◽  
Vol 118 ◽  
pp. 661-665 ◽  
Author(s):  
Dae Hwan Kwon ◽  
Thuy Dang Nguyen ◽  
Pyuck Pa Choi ◽  
Ji Soon Kim ◽  
Young Soon Kwon
Keyword(s):  
Electrical Conductivity ◽  
Ball Milling ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Energy Ball ◽  
Xrd Patterns ◽  
Short Time ◽  
Tib2 Particles

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.

Al-SiC Nanocomposites Produced by Ball Milling and Spark Plasma Sintering

2013 ◽  
Vol 1513 ◽  
Author(s):  
R.C. Picu ◽  
J.J. Gracio ◽  
G.T. Vincze ◽  
N. Mathew ◽  
T. Schubert ◽  
...  
Keyword(s):  
Yield Stress ◽  
Ball Milling ◽  
Spark Plasma Sintering ◽  
High Energy ◽  
Sic Nanoparticles ◽  
Sic Particles ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Energy Ball ◽  
Annealing Experiments

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.

Development of Ni/h-BN Self-Lubricating Composite Powder by High-Energy Ball Milling

2016 ◽  
Vol 869 ◽  
pp. 277-282
Author(s):  
Moisés Luiz Parucker ◽  
César Edil da Costa ◽  
Viviane Lilian Soethe
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
Solid Lubricants ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Second Phase ◽  
Average Particle ◽  
Composite Powders ◽  
The Matrix ◽  
Energy Ball

Solid lubricants have had good acceptance when used in problem areas where the conventional lubricants cannot be applied: under extreme temperatures, high charges and in chemically reactive environments. In case of materials manufactured by powder metallurgy, particles of solid lubricants powders can be easily incorporated to the matrix volume at the mixing stage. In operation, this kind of material provides a thin layer of lubricant that prevents direct contact between the surfaces. The present study aimed at incorporating particles of second phase lubricant (h-BN) into a matrix of nickel by high-energy ball milling in order to obtain a self-lubricating composite with homogeneous phase distribution of lubricant in the matrix. Mixtures with 10 vol.% of h-BN varying the milling time of 5, 10, 15 and 20 hours and their relationship ball/powder of 20:1 were performed. The effect of milling time on the morphology and microstructure of the powders was studied by X-ray diffraction, SEM and EDS. The composite powders showed reduction in average particle size with increasing milling time and the milling higher than 5 hours resulted in equiaxial particles and the formation of nickel boride.

Nickel/Alumina Metal Matrix Nanocomposites Obtained by High-Energy Ball Milling and Spark Plasma Sintering

2018 ◽  
Author(s):  
Enrique Martínez-Franco ◽  
Ming Li ◽  
Ricardo Cuenca Álvarez ◽  
Jesús González Hernández ◽  
Chao Ma ◽  
...  
Keyword(s):  
Ball Milling ◽  
Spark Plasma Sintering ◽  
Metal Matrix ◽  
High Energy ◽  
Alumina Nanoparticles ◽  
Metal Matrix Nanocomposites ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Energy Ball ◽  
Matrix Nanocomposites

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.

Synthesis by High-Energy Ball Milling of MgH2-TiFe Composites for Hydrogen Storage

2017 ◽  
Vol 899 ◽  
pp. 13-18 ◽  
Author(s):  
Ricardo Mendes Leal Neto ◽  
Rafael de Araújo Silva ◽  
Ricardo Floriano ◽  
Graziele Cristina Seco Coutinho ◽  
Railson Bolsoni Falcão ◽  
...  
Keyword(s):  
Ball Milling ◽  
Hydrogen Absorption ◽  
Hydrogen Desorption ◽  
High Energy ◽  
Control Agent ◽  
High Energy Ball Milling ◽  
Absorption Kinetics ◽  
Particle Size Reduction ◽  
Milled Sample ◽  
Energy Ball

The aim of this work is to investigate the influence of some processes variables on the microstructure and hydrogen absorption kinetics of MgH2 - X wt.% TiFe composites. Samples were synthesized by high-energy ball milling in a planetary (X = 40, 50, 60) and shaker mill (X = 40) under high-purity argon atmosphere. Commercial MgH2 instead of Mg powder was used in order to reduce adherence on the vial and balls. TiFe powder was previously produced by ball milling a mixture of TiH2 and Fe powders followed by a reaction synthesis at 600oC. Milled composites samples were characterized by XRD and SEM analysis. Milling time was preliminary investigated (X = 40) in the planetary ball mill (6 to 36h). TiFe particle size reduction was shown to be difficult since they are surrounded by MgH2 matrix. Strong particle reduction was obtained by using a shaker mill only for 2 hours and adding cyclohexane as process control agent. No reaction between MgH2 and TiFe compound was observed in any milled sample. Hydrogen absorption kinetics measurements of the as-milled samples were conducted on an Sieverts' type apparatus at room temperature after hydrogen desorption at 350oC under vacuum. The best hydrogen kinetics (3 wt% at the first hour) was attained by the planetary milled sample (36 h). Higher hydrogen capacity was observed for the sample milled in the shaker mill (4.0 wt.%), but only after 13h.

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