Dependence of secondary operations in powder metallurgy and their impact on the electrical conductivity of MWCNTs/Cu nanocomposites

2021 ◽  
Author(s):  
Mahesh ◽  
Kalyan Kumar Singh ◽  
Vishwanath Koti ◽  
Prashant Rawat
Keyword(s):  
Electrical Conductivity ◽  
Powder Metallurgy ◽  
Secondary Operations

Characterization and Properties of Iron/Silica-Sand-Nanoparticle Composites

2011 ◽  
Vol 316-317 ◽  
pp. 97-106 ◽  
Author(s):  
Tahir Ahmad ◽  
Othman Mamat
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Powder Metallurgy ◽  
Metal Matrix ◽  
Silica Sand ◽  
Particulate Composites ◽  
Powder Metallurgy Technique ◽  
Superior Mechanical Properties ◽  
Iron Based ◽  
Nanoparticle Composites

Metal matrix-particulate composites fabricated by using powder metallurgy possess a higher dislocation density, a small sub-grain size and limited segregation of particles, which, when combined, result in superior mechanical properties. The present study aims to develop iron based silica sand nanoparticles composites with improved mechanical properties. An iron based silica sand nanoparticles composite with 5, 10, 15 and 20 wt.% of nanoparticles silica sand were developed through powder metallurgy technique. It was observed that by addition of silica sand nanoparticles with 20 wt.% increased the hardness up to 95HRB and tensile strength up to 690MPa. Sintered densities and electrical conductivity of the composites were improved with an optimum value of 15 wt.% silica sand nanoparticles. Proposed mechanism is due to diffusion of silica sand nanoparticles into porous sites of the composites.

Characterization and Properties of Copper-Silica Sand Nanoparticle Composites

2011 ◽  
Vol 319-320 ◽  
pp. 95-105 ◽  
Author(s):  
Tahir Ahmad ◽  
Othman Mamat
Keyword(s):  
Mechanical Properties ◽  
Electrical Conductivity ◽  
Plastic Deformation ◽  
Powder Metallurgy ◽  
Silica Sand ◽  
Prealloyed Powder ◽  
Powder Metallurgy Process ◽  
Rearrangement Mechanism ◽  
Nanoparticle Composites ◽  
Metallurgy Process

Copper-based microcomposites fabricated by powder metallurgy with subsequent plastic deformation have received increasing attention over recent years. These microcomposites possess good electrical conductivity in combination with high mechanical properties. The present study aims to explore potential technical merits in developing a prealloyed powder metallurgy copper based composites with silica sand nanoparticles reinforcement. Relevant mechanical properties and electrical conductivity improvements are the main targets. A copper based composite with 5, 10, 15 and 20 wt.% of silica sand nanoparticles were developed through the powder metallurgy process. It was observed that by addition of silica sand nanoparticles with 20% increased the hardness up to 143HV. Optimum electrical conductivity of the composites was achieved in the 15 wt.% silica sand nanoparticles. Advanced particle rearrangement mechanism due to homogeneous and fine distribution of silica sand nanoparticles into pore sites of the composites was also observed. The silica sand nanoparticles composites properties that are much more surface-related seen to be improved convincingly compared with the bulk controlled.

Studies on Preparation of Ti3SiC2 Particulate Reinforced Cu Matrix Composite by Warm Compaction and Its Tribological Behavior

2007 ◽  
Vol 534-536 ◽  
pp. 929-932 ◽  
Author(s):  
Tungwai Leo Ngai ◽  
Zhi Yu Xiao ◽  
Yuan Biao Wu ◽  
Yuan Yuan Li
Keyword(s):  
Electrical Conductivity ◽  
Powder Metallurgy ◽  
Relative Density ◽  
Matrix Composite ◽  
Copper Matrix ◽  
High Density ◽  
Green Density ◽  
Warm Compaction ◽  
Copper Matrix Composite ◽  
Particulate Reinforced

Conventional powder metallurgy processing can produce copper green compacts with density less than 8.3 g/cm3 (a relative density of 93%). Performances of these conventionally compacted materials are substantially lower than their full density counterparts. Warm compaction, which is a simple and economical forming process to prepare high density powder metallurgy parts or materials, was employed to develop a Ti3SiC2 particulate reinforced copper matrix composite with high density, high electrical conductivity and high strength. In order to clarify the warm compaction behaviors of copper powder and to optimize the warm compaction parameters, effects of lubricant concentration and compaction pressure on the green density of the copper compacts were studied. Copper compact with a green density of 8.57 g/cm3 can be obtained by compacting Cu powder with a pressure of 700 MPa at 145°C. After sintered at 1000°C under cracked ammonia atmosphere for 60 minutes, density of the sintered compact reached 8.83 g/cm3 (a relative density of 98.6%). Based on these fabrication parameters a Ti3SiC2 particulate reinforced copper matrix composite was prepared. Its density, electrical conductivity, ultimate tensile strength, elongation percentage and tribological behaviors were studied.

scholarly journals Copper alloys with improved properties: standard ingot metallurgy vs. powder metallurgy

2014 ◽  
Vol 20 (3) ◽  
pp. 207-216
Author(s):  
Milan T. Jovanović ◽  
Višeslava Rajković ◽  
Ivana Cvijović-Alagić
Keyword(s):  
Electrical Conductivity ◽  
Powder Metallurgy ◽  
Mechanical Alloying ◽  
Internal Oxidation ◽  
Copper Alloys ◽  
Microstructural Characterization ◽  
Ingot Metallurgy ◽  
Vacuum Melting ◽  
X Ray ◽  
Scanning Electron

Three copper-based alloys: two composites reinforced with Al2O3 particles and processed through powder metallurgy (P/M) route, i.e. by internal oxidation (Cu-2.5Al composite) and by mechanical alloying (Cu-4.7Al2O3 ) and Cu-0.4Cr-0.08Zr alloy produced by ingot metallurgy (vacuum melting and casting) were the object of this investigation. Light microscope and scanning electron microscope (SEM) equipped with electron X-ray spectrometer (EDS) were used for microstructural characterization. Microhardness and electrical conductivity were also measured. Compared to composite materials, Cu-0.4Cr-0.08Zr alloy possesses highest electrical conductivity in the range from 20 to 800 ℃, whereas the lowest conductivity shows composite Cu-2.5Al processed by internal oxidation. In spite to somewhat lower electrical conductivity (probably due to inadequate density), Cu-2.5Al composite exhibits thermal stability enabling its application at much higher temperatures than materials processed by mechanical alloying or by vacuum melting and casting.

Fabrication of W-Cu/Lu2O3 Composites with High Strength and Electrical Conductivity Prepared by Electroless Plating and Powder Metallurgy

2016 ◽  
Vol 849 ◽  
pp. 825-830
Author(s):  
Ze Long Lu ◽  
Lai Ma Luo ◽  
Jun Zhang ◽  
Yong Qing Qin ◽  
Xin Min Huang ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Powder Metallurgy ◽  
Electroless Plating ◽  
Bending Strength ◽  
High Strength ◽  
National Standard ◽  
Diffraction Field ◽  
X Ray Diffraction ◽  
X Ray ◽  
Standard Value

W–Cu (0, 0.25, 0.75, 1.5, and 3 wt.%)/Lu2O3 composite materials were prepared through electroless plating with simplified pretreatment method and powder metallurgy. The phases and morphologies of the W–Cu/Lu2O3 composites were characterized by X-ray diffraction, field emission scanning electron microscopy and energy dispersive spectroscopy. The relative density, microhardness, electrical conductivity, and bending strength of the sintered samples were examined. The experimental results show that W–Cu composites with uniform structures can be obtained with pretreated W using the simplified method, followed by electroless Cu plating. The microstructure and properties of the composites were significantly affected by the addition of Lu2O3 nanoparticles, resulting in high electrical conductivity and strength. The electrical conductivity of W–Cu/1.5 wt.% Lu2O3 composites reached 63.3%, which is higher than the national standard value of 50.71%. The bending strength of W–Cu/1.5 wt. % Lu2O3 reached 1306.7 MPa, which is 65.41% higher than the national standard. These results may be attributed to the uniform distribution of refined particles with Lu2O3 content increased to 1.5 wt. %.

scholarly journals Microstructure and Microanalysis Studies of Copper-Nickel-Tin Alloys Obtained by Conventional Powder Metallurgy Processing

2010 ◽  
Vol 660-661 ◽  
pp. 29-34 ◽  
Author(s):  
Waldemar Alfredo Monteiro ◽  
Juan Alfredo Guevara Carrió ◽  
Terezinha Jocelen Masson ◽  
C.D. Abreu ◽  
I.M. Marques ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Comparative Analysis ◽  
Powder Metallurgy ◽  
Powder Diffraction ◽  
Sintered Density ◽  
Microstructural Analysis ◽  
Microstructural Development ◽  
X Rays ◽  
Powder Diffraction Data ◽  
Tin Alloys

The aim of this article was to analyze the microstructural development in samples of Cu-Ni-Sn alloys (weight %) obtained by powder metallurgy (P/M). The powders were mixed for 1/2 hour. After this, they were pressed, in a cold uniaxial pressing (1000 kPa). In the next step the specimens were sintered at temperatures varying from 650 up to 780°C under vacuum. Secondly, the samples were homogenized at 500oC for several special times. The alloys were characterized by optical microscopy, electrical conductivity and Vickers hardness. X rays powder diffraction data were collected for the sintered samples in order to a structural and microstructural analysis. The comparative analysis is based on the sintered density, densification parameter, hardness, macrostructures and microstructures of the samples.

Sign in / Sign up

Export Citation Format

Share Document