Effect of High Energy Milling Time of the Aluminum Bronze Alloy Obtained by Powder Metallurgy with Niobium Carbide Addition

In order to synthesize WC-Co nanopowders through an integrated mechanical and thermal activation process, WO3-Co2O3-C nanopowders need to be obtained first. It is critical how to obtain the WO3-Co2O3-C nanopowders efficiently. The effect of processing parameters on the grain size during high-energy-milling of WO3-Co2O3-C mixed powders was studied via X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the grain size of reactants can be effectively decreased with increasing the milling time, rotation speed, and charge ratio. After a certain time milling, both WO3 and C powders achieve nano-level in grain size and mixed homogeneously. The appropriate milling parameters for fabricating nanosized WO3+C+Co2O3 powders are suggested to be 4 to 8 hours of milling time, 400 RPM of rotation speed, and 40:1 to 60:1 of charge ratio.

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Preparation of Molybdenum High Speed Tool Steels with Addition of Niobium Carbide by Powder Metallurgy Techniques

Materials Science Forum ◽

10.4028/www.scientific.net/msf.802.102 ◽

2014 ◽

Vol 802 ◽

pp. 102-107 ◽

Cited By ~ 1

Author(s):

Oscar Olimpio de Araújo Filho ◽

Rodrigo Tecchio Antonello ◽

Cezar Henrique Gonzalez ◽

Severino Leopoldino Urtiga Filho ◽

Francisco Ambrozio Filho

Keyword(s):

Electron Microscopy ◽

Scanning Electron Microscopy ◽

Powder Metallurgy ◽

Liquid Phase ◽

High Speed ◽

Niobium Carbide ◽

High Energy ◽

Tool Steels ◽

Vacuum Sintering ◽

Scanning Electron

High speed steels processed by Powder Metallurgy (PM) techniques present better mechanical properties when compared with similar steels obtained by the conventional process of cast to ingot and hot working. PM techniques produce improved microstructures with smaller and better distribution of carbides. Liquid phase sintering high speed steel seems to be a cheaper processing route in the manufacturing of tool steels if compared to the well-known and expansive hot isostatic pressing high speed steels. The introduction of niobium as alloying element began with the object of replacing elements like vanadium (V) and tungsten (W). Phase liquid sintering consists in a manufacturing technique to process high speed steels by powder metallurgy. The aim of this work of research is to process and obtain AISI M2 and M3:2 with and without the addition of niobium carbide by high energy milling, cold uniaxial compaction and vacuum sintering in the presence of a liquid phase. The powders of the AISI M2 and M3:2 were processed by high energy milling adding a small quantity of niobium carbide (6% in mass), then the powders were characterized by means of X-ray diffraction (XRD) and scanning electron Microscopy (SEM) plus energy dispersion spectroscopy (EDS) in order to evaluate the milling process. The powders of the AISI M2 and M3:2 with the addition of niobium carbide (NbC) were uniaxially cold compacted and then submitted to vacuum sintering. The sintered samples had their microstructure, porosity and carbide distribution observed and evaluated by means of Scanning Electron Microscopy (SEM) and the mechanical property of hardness was investigated by means of Vickers hardness tests. At least five samples of each steel were investigated.

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Influence of High Energy Milling Time on the Ti-50Ta Biomedical Alloy Structure

Acta Physica Polonica A ◽

10.12693/aphyspola.130.1033 ◽

2016 ◽

Vol 130 (4) ◽

pp. 1033-1036 ◽

Cited By ~ 3

Author(s):

I. Matuła ◽

G. Dercz ◽

M. Zubko ◽

K. Prusik ◽

L. Pająk

Keyword(s):

Milling Time ◽

High Energy ◽

Alloy Structure ◽

High Energy Milling ◽

Biomedical Alloy

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Influence of the Oxide and Ethanol Surface Layer on Phase Transformation of Al-Based Nanocomposite Powders under High-Energy Milling

Materials ◽

10.3390/ma12081305 ◽

2019 ◽

Vol 12 (8) ◽

pp. 1305 ◽

Cited By ~ 1

Author(s):

Dora Janovszky

Keyword(s):

Particle Size ◽

Milling Time ◽

High Energy ◽

Amorphous Structure ◽

Control Agent ◽

Dry Milling ◽

Process Control Agent ◽

Composite Powders ◽

High Energy Milling ◽

Nanocomposite Powders

Pure Al particles reinforced with amorphous-nanocrystalline Cu36Zr48Ag8Al8 particles composite powders were prepared by high-energy milling without and with ethanol. The mechanical milling procedures were compared so that in the case of dry milling the particle size increased owing to cold welding, but the crystallite size decreased below 113 nm. The amorphous phase disappeared and was not developed until 30 h of milling time. Using ethanol as a process control agent, the particle size did not increase, while the amorphous fraction increased to 15 wt.%. Ethanol decomposed to carbon dioxide, water, and ethane. Its addition was necessary to increase the amount of the amorphous structure.

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Influence of High Energy Milling on the Airflow Sensorproperty of the NBCa Ceramic

Materials Science Forum ◽

10.4028/www.scientific.net/msf.727-728.499 ◽

2012 ◽

Vol 727-728 ◽

pp. 499-504 ◽

Cited By ~ 1

Author(s):

C. Caldart ◽

J. Souza ◽

M.Z. Pellegrin ◽

Glaucea Warmeling Duarte ◽

M.R. Rocha ◽

...

Keyword(s):

Particle Size ◽

Milling Time ◽

Weather Forecasting ◽

High Energy ◽

Monitoring And Control ◽

Sem Images ◽

High Energy Milling ◽

Reliable Temperature ◽

Precursor Powders ◽

Airflow Sensor

Some materials have been applied in many surrounding conditions as sensors, electronic devices and other applications. Inexpensive and reliable temperature and flow measurement are important in many applications including, for example, environmental monitoring and control, indoor air conditioning, weather forecasting, automotive and aerospace systems. Special ceramics are an example of such materials. Neodymium-Barium-Copper is a special ceramic that has high electrical conductivity and airflow sensor characteristics. This property is influenced by high energy milling of the powder, when it is not sintered. To evaluate the influence of this type of milling it was carried out an analysis of particle size as a function of milling time. SEM images and granulometric analysis showed significant reduction of particle size with the increase of milling time. For longer times of milling the mixture of precursor powders is favored, resulting in better homogeneity of the ceramic. This is reflected in the properties of airflow sensor.

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Densification Study of Cu-Al-SiC Composite Powders Prepared by Mechanical Milling

Materials Science Forum ◽

10.4028/www.scientific.net/msf.793.37 ◽

2014 ◽

Vol 793 ◽

pp. 37-44

Author(s):

C.A. León-Patiño ◽

D. Ramírez-Vinasco ◽

E.A. Aguilar-Reyes

Keyword(s):

Milling Time ◽

Maximum Load ◽

High Energy ◽

Milling Process ◽

Homogeneous Distribution ◽

Composite Powders ◽

Coarse Aggregates ◽

High Energy Milling ◽

Compaction Behavior ◽

The Matrix

This work involves the preparation of Cu-Al-SiC composite powders by a high-energy milling process and the study of their densification behavior by cold compaction. The goal of the milling process is to get embedded the ceramic particles in the metal matrix to enhance the distribution of the metal and ceramic phases in the compacts, an important condition to derive in isotropic properties of consolidated materials. For comparison purposes, compressibility tests of a Cu-5Al matrix prepared by high-energy milling were performed; while additions of 1, 5 and 10 vol.% SiC were added to the matrix. It was found that the high-energy milling process leads to Cu-Al-SiC composite powders with a homogeneous distribution of the reinforcement in the matrix. Compressibility essays showed that densification of the powders decreased with SiC content; a densification of 73.7% was obtained for composites with 10% SiC compared to 76.0% for samples with 1% SiC at the maximum load applied. Milling time reduced the plastic deformation capacity of the matrix leading to fracture of the cold welded aggregates; the fracture process was accelerated by the addition of the hard reinforcement particles. Thus, morphology of the powders changed from laminar, to fine fragments and coarse aggregates, affecting the compaction behavior.

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Researched the Collision Model of Aluminium-Flakes by High Energy Milling (HEM)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.146-147.1256 ◽

2010 ◽

Vol 146-147 ◽

pp. 1256-1259

Author(s):

Xiao Lan Cai ◽

Zhi Ming Pei

Keyword(s):

Milling Time ◽

High Energy ◽

Collision Model ◽

Technical Indicators ◽

High Energy Milling ◽

Relationship Of ◽

The Relationship

This paper applied to relations of the milling time、flakes thickness and diameter size D50 of Al-flakes by High Energy Milling(HEM) use the Benjaminm collision model. Through established of the collision model, the relationship of various technical indicators can be calculated of the flakes, and it can be used to guidance of the preparation and optimize the process.

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