Development and characterization of bronze-Cr-Ni composites produced by powder metallurgy

2015 ◽  
Vol 22 (4) ◽  
Author(s):  
Aykut Canakci ◽  
Temel Varol ◽  
Hamdullah Cuvalci ◽  
Fatih Erdemir ◽  
Serdar Ozkaya
Keyword(s):  
Green Density ◽  
Contact Materials ◽  
X Ray ◽  
Ni Content ◽  
Compact Pressure ◽  
Electrical Conductivities ◽  
Lower Porosity ◽  
Microstructure Density ◽  
Hardness Values

AbstractIn this study, the bronze-Cr-Ni composites were prepared by means of the powder metallurgical method. The influence of the composition and compact pressure on microstructure, density, hardness and electrical conductivity was examined. Scanning electron microscope (SEM) and energy dispersive X-ray analysis (EDX) were used to analyze the microstructure of the contact materials. The results showed that density of the bronze-Cr-Ni composites decreased with increasing Ni content. Increasing compact pressure led to lower porosity and consequently improved the density of bronze-Cr-Ni composites. The relative green density increased from 78% to 95% with the increase in the compact pressure from 200 MPa to 800 MPa. The hardness values showed a decrease from 95.1 BHN to 71.6 BHN by the addition of Ni from 1 wt% to 5 wt% at 800 MPa. It was found that addition of Ni at 1 wt% was required to achieve increased hardness and sufficient conductivity for bronze-Cr-Ni composites. The electrical conductivities of contact materials containing 3 wt% Ni and 5 wt% Ni was lower than that of 1 wt% Ni.

Characterization of Cold Sprayed Copper Coatings on Al Alloy Substrate

2015 ◽  
Vol 3 (2) ◽  
pp. 41-53
Author(s):  
Tarun Goyal ◽  
T. S. Sidhu ◽  
R. S. Walia
Keyword(s):  
Spray Deposition ◽  
Structural Characteristics ◽  
Al Alloy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Copper Coatings ◽  
Powder Particles ◽  
Micro Analysis ◽  
Hardness Values

This study reveals the successful low pressure cold spray deposition of near-uniform, defect free and dense copper coatings approximately 700-1900 µm thick, on Al alloy for electro-technical applications. The micro structural characteristics of the deposits have been studied using the combined techniques of X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) and electron-probe micro analysis (EPMA). The coatings exhibited characteristic splat-like, layered morphologies due to the deposition of solid powder particles which appeared to have been plastically deformed on impact to the substrate. The developed coatings have a dense (in the range of 3090-5015 kg/m3)and nearly uniform microstructure, with almost uniform hardness values in the range of 120 -140 Hv, and electrical conductivity in the range of 23-30 MS/m. EDAX, XRD and EPMA results revealed that the main constituent in the coating is Cu.

scholarly journals Effect of Subsequent Aging in SiCP Reinforced AA2124 Aluminum Metal Matrix Composite

2009 ◽  
Vol 18 (5) ◽  
pp. 096369350901800 ◽  
Author(s):  
Yahya Bozkurt ◽  
Recep Artir ◽  
Hüseyin Uzun ◽  
Serdar Salman
Keyword(s):  
Metal Matrix ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
Subsequent Aging ◽  
X Ray ◽  
Aluminum Metal ◽  
Aluminum Metal Matrix Composite ◽  
Hardness Values ◽  
Scanning Electron

The present study is focused on the evaluation of the aging behaviour and microstructure characterization of AA2124/SiC/25p composite under the aging temperatures of 180, 185 and 190 °C for various dwelling time ranging from 0 up to 100 hours. The microstructure was characterized by means of scanning electron microscopy. The hardness, energy dispersive spectroscopy analysis and X-ray diffraction measurements were also performed to evaluate the characteristics of aged AA2124/SiC/25p composite. The results show that the hardness values of as-received composite were considerably improved up to two third by the subsequent aging. The hardness increasing was attributed to the presence of CuAl2, Al4SiC4 and precipitation phases in aged AA2124/SiC/25p composite.

Porous Ceramic as Air Humidity Sensors

2012 ◽  
Vol 727-728 ◽  
pp. 545-549
Author(s):  
Rodrigo de Matos Oliveira ◽  
Maria do Carmo de Andrade
Keyword(s):  
Porous Ceramic ◽  
Air Humidity ◽  
Climatic Chamber ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Microstructure Density ◽  
Humidity Monitoring ◽  
Sem Microstructure

The development of sensors for relative humidity monitoring, with national technology, is one of the greatest needs identified by National Institute for Space Research (INPE) to allow concerned future projects and minimize dependence on imported components and materials. Therefore, in this work, porous ceramic was manufactured from ZrO2 and TiO2 powders, compacted and sintered at different temperatures, for application as air humidity sensing elements. The characterization of the sintered ceramics were carried out through x-ray diffraction (crystalline phases), scanning electron microscopy, SEM (microstructure), density determination and capacitance measurements using a RLC bridge in a climatic chamber. The results evidenced that the air humidity ceramic sensing elements are very promising ones.

Laser ternary Hf-Nb-Zr composites coatings on Ti6Al4V alloy for biomedical application

2018 ◽  
Vol 233 (3) ◽  
pp. 1099-1107
Author(s):  
API Popoola ◽  
L Phume ◽  
VS Aigbodion
Keyword(s):  
Biomedical Application ◽  
Corrosion And Wear ◽  
Ti6al4v Alloy ◽  
Wear Loss ◽  
X Ray Diffraction ◽  
Wear Properties ◽  
X Ray ◽  
Volume Wear ◽  
Hardness Values

Ti6Al4V alloy has been found to be the leading material for hip replacement due to its biocompatibility and good yield strength; however poor corrosion and wear properties are experienced in human tissue surroundings. Laser metal deposition was accomplished on Ti6Al4V alloy using: 25Hafnium, 50Niobium, and 25Zirconium reinforcements with the aid of Nd:YAG Rofin Sinar laser. Characterization of the produced deposits was carried out by optical microscopy, scanning electron microscopy/energy-dispersive X-ray spectroscopy and X-ray diffraction. Hardness, corrosion and wear analyses were also done. Microstructure of 25Hf-50Nb-25Zr coatings indicated homogeneous microstructures of both α and β phases. More α acicular phases were formed than β phases. The 25Hf-50Nb-25Zr coating on Ti6Al4V reduced the content of aluminium and vanadium on the substrate. Maximum hardness value and lowest volume wear rate were obtained at laser power of 1250 W with hardness values of 599.18 HV and 0.6 m3 volume wear loss. Improvement in corrosion resistance of 99.98% was obtained. It was established that improved properties were obtained after laser surface cladding of 25Hf-50Nb-25Zr on Ti6Al4V alloy.

Microstructural Characterization of Clay-Based Ceramics with the Addition of Granite Residues

2019 ◽  
Vol 958 ◽  
pp. 123-128
Author(s):  
Monica Castoldi Borlini Gadioli ◽  
Mariane Costalonga de Aguiar ◽  
Carlos Maurício Fontes Vieira ◽  
Fabio da Costa Garcia Filho ◽  
Sergio Neves Monteiro
Keyword(s):  
Microstructural Analysis ◽  
High Capacity ◽  
Microstructural Characterization ◽  
Ceramic Matrix ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ornamental Stones ◽  
Lower Porosity ◽  
Scanning Electron

Million tons of ornamental stones residues are produced every year. Most of this residue is disposed without any kind of processing or treatment. Moreover, disposal occurs without a prospective of reuse or recycling. The incorporation into ceramics is a possible alternative for part of this residue. Clay-based ceramics have high capacity of incorporation of industrial residues. This work aimed to conduct a microstructural characterization of clay-based ceramics with incorporation of granite residues in the composition of the ceramic matrix. Specimens were produced with the addition of 0, 10, 20 and 30 wt. % of granite residues. The specimens were prepared by uniaxial pressing and sintered at temperatures of 1050 and 1200°C. For the microstructural analysis were carried out by scanning electron microscopy and X-ray diffraction. The results indicated that the incorporated ceramics sintered at 1200oC presented higher densification and lower porosity as compared with those sintered at 1050oC.

scholarly journals Synthesis and Characterization of Ti-Sn Alloy for Orthopedic Application

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7660
Author(s):  
Ambreen Azmat ◽  
Muhammad Tufail ◽  
Ali Dad Chandio
Keyword(s):  
Corrosion Resistance ◽  
Elastic Modulus ◽  
Corrosion Rate ◽  
Orthopedic Implant ◽  
X Ray ◽  
Hardness Tester ◽  
Excellent Corrosion Resistance ◽  
Drastic Increase ◽  
Hardness Values

Titanium (Ti)-based alloys (e.g., Ti6Al4V) are widely used in orthopedic implant applications owing to their excellent mechanical properties and biocompatibility. However, their corrosion resistance needs to be optimized. In addition, the presence of aluminum and vanadium cause alzheimer and cancer, respectively. Therefore, in this study, titanium-based alloys were developed via powder metallurgy route. In these alloys, the Al and V were replaced with tin (Sn) which was the main aim of this study. Four sets of samples were prepared by varying Sn contents, i.e., 5 to 20 wt. %. This was followed by characterization techniques including laser particle analyzer (LPA), X-ray diffractometer (XRD), scanning electron microscope (SEM), computerized potentiostate, vicker hardness tester, and nanoindenter. Results demonstrate the powder sizes between 50 and 55 µm exhibiting very good densification after sintering. The alloy contained alpha at all concentrations of Sn. However, as Sn content in the alloy exceeded from 10 wt. %, the formation of intermetallic compounds was significant. Thus, the presence of such intermetallic phases are attributed to enhanced elastic modulus. In particular, when Sn content was between 15 and 20 wt. % a drastic increase in elastic modulus was observed thereby surpassing the standard/reference alloy (Ti6Al4V). However, at 10 wt. % of Sn, the elastic modulus is more or less comparable to reference counterpart. Similarly, hardness was also increased in an ascending order upon Sn addition, i.e., 250 to 310 HV. Specifically, at 10 wt. % Sn, the hardness was observed to be 250 HV which is quite near to reference alloy, i.e., 210 HV. Moreover, tensile strength (TS) of the alloys were calculated using hardness values since it was very difficult to prepare the test coupons using powders. The TS values were in the range of 975 to 1524 MPa at all concentrations of Sn. In particular, the TS at 10 wt. % Sn is 1149 MPa which is comparable to reference counterpart (1168 MPa). The corrosion rate of Titanium-Sn alloys (as of this study) and reference alloy, i.e., Ti6Al4V were also compared. Incorporation of Sn reduced the corrosion rate at large than that of reference counterpart. In particular, the trend was in decreasing order as Sn content increased from 5 to 20 wt. %. The minimum corrosion rate of 3.65 × 10−9 mm/year was noticed at 20 wt. % than that of 0.03 mm/year of reference alloy. This shows the excellent corrosion resistance upon addition of Sn at all concentrations.

Characterization of Micro-Arc Oxidation Coatings Formed on Biomedical Ni-Cr-Mo Alloy

2011 ◽  
Vol 337 ◽  
pp. 29-32
Author(s):  
Ji Lin Xu ◽  
De Zhen Yu ◽  
Jun Ming Luo
Keyword(s):  
Corrosion Resistance ◽  
Coated Sample ◽  
X Ray Diffraction ◽  
Cross Sectional ◽  
X Ray ◽  
Ni Content ◽  
Polarization Test ◽  
Micro Arc Oxidation ◽  
Chemical And Phase Compositions

In this paper, the micro-arc oxidation coatings formed on biomedical Ni-Cr-Mo alloy were characterized by surface and cross-sectional morphologies, chemical and phase compositions and corrosion resistance using scanning electron microscopy (SEM), Energy dispersive X-ray spectrometer (EDS), X-ray diffraction (XRD) and potentiodynamic polarization test, respectively. The results show that the coating is mainly composed of γ-Al2O3 crystal phase with a little Ni content. The coating possesses a typical porous surface and has a thickness of ~6 μm. The corrosion resistance of the coated sample is greatly improved compared with the uncoated Ni-Cr-Mo alloy.

Structural and mechanical characterization of re-pressed and annealed iron-alumina metal matrix nanocomposites

2017 ◽  
Vol 52 (11) ◽  
pp. 1541-1556 ◽  
Author(s):  
Shyam Sharma ◽  
Rupal Jain ◽  
Vineet Rawat ◽  
Prateek Rajeev Hundekar ◽  
Neera Singh ◽  
...  
Keyword(s):  
Metal Matrix ◽  
Electron Microscopic ◽  
Metal Matrix Nanocomposites ◽  
Maximum Deformation ◽  
Heat Treated ◽  
Ball Milling Technique ◽  
Microstructure Density ◽  
Matrix Nanocomposites ◽  
Hardness Values

In this study, structural and mechanical properties of re-pressed and annealed iron (Fe)-alumina (Al2O3) metal matrix nanocomposites (MMNCs) was investigated. Composite composition with 5 wt.% of alumina to iron was fabricated using ball milling technique. Cylindrical sintered specimens were pressed at a load of 10, 12.5, and 15 kN in a die of similar diameter so as to have maximum deformation internally at grain as well as at grain boundary. These specimens were heat treated at 900, 1000, and 1100℃ for 1 h to anneal the stresses as well as to enhance the bonding between grains. Synthesized specimens were characterized for their microstructure, density and hardness respectively. Scanning electron microscopic images of the synthesized specimens revealed the formation of dense phase microstructure along with the presence of nano-dispersion of iron aluminate (FeAl2O4) phase. Secondary processing of metal matrix nanocomposites resulted in an increase in density of prepared specimens from 4.6960 to 5.5035 g/cm3 and the hardness values increased from 63 to 94 HRH.

Preparation and Characterization of Poly(vinyl Butyral)-Polyaniline-Montmorillonite Nanocomposites

2012 ◽  
Vol 18-19 ◽  
pp. 291-297
Author(s):  
Priscila Anadão ◽  
Francisco Rolando Valenzuela-Díaz ◽  
Hélio Wiebeck
Keyword(s):  
Clay Mineral ◽  
X Ray Diffraction ◽  
Sodium Montmorillonite ◽  
X Ray ◽  
Final Configuration ◽  
Electrical Conductivities ◽  
Diffraction Patterns ◽  
Vinyl Butyral ◽  
Montmorillonite Nanocomposites

Poly(vinyl butyral)-polyaniline-sodium montmorillonite nanocomposites were prepared via polymerization of aniline between clay mineral platelets at two different pH levels (2.0 and 5.0), followed by dispersion of the polyaniline-sodium montmorillonite nanocomposite in a poly(vinyl butyral) solution. A comparison was made of the effect of the pH levels and the polyaniline-sodium montmorillonite nanocomposite precursor on the final structures of the poly(vinyl butyral) nanocomposites and their electrical conductivities. X-ray diffraction patterns revealed the formation of nanocomposites at both pH levels. UV-Vis spectra indicated that the polyaniline formed at both pH levels was conductive, with the UV-Vis spectra presenting a band at 420 nm corresponding to the polaronic form and the beginning of a new band at 600 nm indicating the presence of polaronic segments. FTIR spectra revealed the peaks of the groups present in polyaniline and poly(vinyl butyral) nanocomposites. The electrical conductivities of the polyaniline and poly(vinyl butyral) nanocomposites prepared at pH 2.0 were lower than those of the same nanocomposites prepared at pH 5.0, probably due to the lower formation of polyaniline chains in a more acidic dispersion and to the final configuration of polyaniline in the nanocomposites.

The Use of Advanced Analytical Techniques for Characterization of the Chemical, Physical, and Crystallographic Nature of a Surface

1973 ◽  
Vol 31 ◽  
pp. 132-133 ◽  
Author(s):  
R. E. Herfert
Keyword(s):  
Surface Characterization ◽  
Analytical Techniques ◽  
X Ray Diffraction ◽  
Depth Of Penetration ◽  
X Ray ◽  
The Past ◽  
Transmission Electron ◽  
Scanning Electron

Studies of the nature of a surface, either metallic or nonmetallic, in the past, have been limited to the instrumentation available for these measurements. In the past, optical microscopy, replica transmission electron microscopy, electron or X-ray diffraction and optical or X-ray spectroscopy have provided the means of surface characterization. Actually, some of these techniques are not purely surface; the depth of penetration may be a few thousands of an inch. Within the last five years, instrumentation has been made available which now makes it practical for use to study the outer few 100A of layers and characterize it completely from a chemical, physical, and crystallographic standpoint. The scanning electron microscope (SEM) provides a means of viewing the surface of a material in situ to magnifications as high as 250,000X.

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