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.

Strengthening in CNT-Al Composites Produced by High-Energy Ball Milling

2011 ◽  
Vol 236-238 ◽  
pp. 2336-2339 ◽  
Author(s):  
Xiao Fei Wang ◽  
Xiao Lan Cai
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Matrix Composites ◽  
The Matrix ◽  
Energy Ball ◽  
Al Matrix Composites ◽  
Ball Milling Time

In this paper, carbon nanotubes (CNT)-reinforced aluminum (Al) matrix composites were fabricated by High-Energy Ball Milling, the objective was to investigate the evolvement of particle size, density and hardness of CNT-Al composites with increasing wt% CNT, and analyzed the micrographs of mixture powders at different milling time. The results showed that the addition of CNT can play a role of grinding aid to refine grain, improve the hardness and decrease the density, and CNT can be homogeneous dispersed in the matrix with increasing ball-milling time, it also showed that too much CNT was no help on hardness, this attributed to clustering of CNT, the proper addition of CNT was 2wt%, and the mixture powders could reached a state of equilibrium between fracturing and cold-welding at 75min.

Mechanical Properties and Fracture Characterization of Al-5%wtMg Composite Reinforced with Carbon Nanotube

2013 ◽  
Vol 750-752 ◽  
pp. 186-190
Author(s):  
Ya Guang Chen ◽  
Xiao Lan Cai ◽  
Hong Peng Sun ◽  
Gang Le ◽  
Cui Hu
Keyword(s):  
Ball Milling ◽  
Load Transfer ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Composite Powders ◽  
Fracture Characterization ◽  
Grinding Aids ◽  
Disperse Carbon ◽  
The Matrix ◽  
Energy Ball

High-Energy Ball Milling was used to disperse carbon nanotubes (CNTs) in Al-5wt%Mg matrix and hot-pressing were used to consolidate the composite powders with different CNTs contents. The results showed that a certain weight of CNTs can be homogeneously dispersed in the matrix through the high-energy ball milling, the most of CNTs are embedded in the Al-5wt%Mg matrix and have a close bonding with the Al-5wt%Mg matrix. In addition, CNTs can play the role of grinding aids to prevented agglomeration of particles. Tensile strength and hardness of the CNTs/Al-5wt%Mg composites increase by 47.9% and 37.25% respectively when the CNTs was 2wt% in the Al-5wt%Mg composites. The fracture surfaces of the composite with 2wt% CNTs involved in the pulling out and breakage of CNTs. In this case, both Orowan looping and load transfer were proved to be the strengthening mechanisms of the CNTs/ Al-5wt%Mg composites.

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.

Physical and Electrochemical Properties of SiOx /C Composites Prepared by a Combination of Spray Pyrolysis and High Energy Ball Milling

2015 ◽  
Vol 1775 ◽  
pp. 7-12 ◽  
Author(s):  
Anara Molkenova ◽  
Izumi Taniguchi
Keyword(s):  
Electrochemical Properties ◽  
Spray Pyrolysis ◽  
Ball Milling ◽  
Ultrasonic Spray Pyrolysis ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Potential Range ◽  
Composite Powders ◽  
Ultrasonic Spray ◽  
Energy Ball

ABSTRACTSpray pyrolysis has been widely used to prepare homogeneous and uniform ceramic powders with high purity. In this study, we are proposing ultrasonic spray pyrolysis followed by heat treatment to produce SiOx/C composite powders, where sucrose was used as a carbon source. Furthermore, high energy ball milling of the as-prepared powders in the presence of acetylene black was conducted to activate its electrochemical properties by reducing the particle size and improving the functionalization of the SiOx composite particles. SiOx/C nanocomposite finally obtained at a sucrous concentration of 0.1 mol L-1 showed superior electrochemical properties, and the SiOx/C nanocomposite electrode delivered the first discharge and charge capacities of 1252 and 819 mAh g-1, respectively, with an initial columbic efficiency of 65% at a current density of 50 mAh g-1 in the potential range from 0.01 to 3 V versus Li/Li+.

Preparation of Cu-Zn Alloy by Different High Energy Ball Milling

2011 ◽  
Vol 412 ◽  
pp. 259-262
Author(s):  
Kai Jun Wang ◽  
Xiao Lan Cai ◽  
Hua Wang ◽  
Jin Hu ◽  
Yun Feng Zhang
Keyword(s):  
Ball Milling ◽  
Milling Time ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Attrition Mill ◽  
Phase Form ◽  
Elemental Copper ◽  
Energy Ball ◽  
New Phase ◽  
Zn Alloy

Cu-Zn alloy was prepared by high energy ball milling of elemental copper and zinc by the Simoloyer attrition mill, the different parameters such as milling time, ball-to-powder ratio and rotational speeds were analyzed. The results show that the different Cu-Zn alloy phase can be produced by different ball milling parameters, It has been found that milling time is highly significant to refining process, and the ratios of ball to powder are also benefited to the new phase form.

Carbon Nanotubes Reinforced Aluminum Matrix Composites by High-Energy Ball Milling

2010 ◽  
Vol 150-151 ◽  
pp. 1163-1166 ◽  
Author(s):  
Xiao Fei Wang ◽  
Xiao Lan Cai
Keyword(s):  
Mechanical Properties ◽  
Ball Milling ◽  
Milling Time ◽  
Aluminum Matrix ◽  
High Energy ◽  
High Energy Ball Milling ◽  
Aluminum Matrix Composites ◽  
Matrix Composites ◽  
Energy Ball ◽  
Rotary Speed

CNT-reinforced aluminum matrix composites was produced by high-energy ball milling, the effect of rotary speed and milling time on the particle size distribution,the density and hardness of CNT-aluminum matrix composites were studied,it was observed that the rotary speed and milling time have an important effect on the mechanical properties of the CNT-aluminum matrix composites.

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