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.

Microstructural and Mechanical Properties of Ti3Al-Based Intermetallics Produced by Powder Metallurgy

2005 ◽  
Vol 494 ◽  
pp. 211-216 ◽  
Author(s):  
B. Dimčić ◽  
M. Vilotijević ◽  
D. Božić ◽  
D. Rajnović ◽  
M.T. Jovanović
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Room Temperature ◽  
Solution Treatment ◽  
Microstructural Characterization ◽  
Compression Tests ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

The structural and compression mechanical properties of Ti3Al-based intermetallics produced by powder metallurgy techniques have been studied. The as-milled powders were compacted by hot pressing to non-porous homogenous compacts. Prior to compression tests, all compacts were homogenized by a solution treatment at 1050°C (a+β region) for 1h, followed by water quenching. The compression tests were performed from room temperature to 500°C in vacuum at a strain rate of 1 3 10 4 . 2 − − × s . Detailed microstructural characterization was evaluated by scanning electron microscopy (SEM), followed by energy dispersive spectroscopy (EDS) and X-ray diffraction analysis.

The Synthesis of Cu0.81Ni0.19 Intermetallics by Mechanical Alloying

2012 ◽  
Vol 496 ◽  
pp. 379-382
Author(s):  
Rui Song Yang ◽  
Ming Tian Li ◽  
Chun Hai Liu ◽  
Xue Jun Cui ◽  
Yong Zhong Jin
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Grain Size ◽  
Mechanical Alloying ◽  
Milling Time ◽  
Elemental Powder ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scherrer Equation ◽  
Scanning Electron

The Cu0.81Ni0.19 has been synthesized directly from elemental powder of nickel and copper by mechanical alloying. The alloyed Cu0.81Ni0.19 alloy powders are prepared by milling of 8h. The grain size calculated by Scherrer equation of the NiCu alloy decreased with the increasing of milling time. The end-product was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM)

scholarly journals Karakterisasi Mineral Magnetik Sedimen Sungai Citarum Hilir Melalui Analisa Sifat Magnetik, Mineralogi serta Morfologi Magnetik

POSITRON ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 52
Author(s):  
Kartika Hajar Kirana ◽  
Mechdi Ghazali ◽  
Luh Ayu Eka Safitri Septiana ◽  
Dini Fitriani ◽  
Eleonora Agustine ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Total Dissolve Solid ◽  
X Ray ◽  
Scanning Electron

Sungai Citarum merupakan sungai utama yang ada di Provinsi Jawa Barat yang sangat penting bagi kehidupan sosial dan ekonomi. Di bagian hilir, Sungai Citarum ini banyak melewati daerah pemukiman padat penduduk, daerah industri, dan bahkan pesawahan. Oleh karena itu, perlu kajian mengenai kondisi Sungai Citarum salah satunya dengan mengidentifikasi parameter electrical conductivity (EC), total dissolve solid (TDS), pH dan suhu serta karakteristik mineral magnetik pada sedimen melalui analisis sifat magnetik, mineralogi dan morfologi magnetiknya. Pengukuran parameter EC, TDS, pH dan suhu dilakukan secara in situ pada sampel air Sungai Citarum, pengukuran sifat magnetik dilakukan pada sampel sedimen yang telah dipreprasi, sedangkan pengukuran mineralogi dan morfologi dilakukan pada sampel sedimen yang telah diekstraksi. Sifat magnetik sedimen diketahui dari nilai suseptibilitas magnetik dual frekuensi yang diukur menggunakan Bartington Magnetik Susceptibilitymeter, sedangkan mineralogi dan morfologi magnetik diketahui berdasarkan hasil pengukuran scanning electron microscope–energy disperdsive x-ray (SEM-EDS) dan x-ray diffractometer (XRD). Hasil pengukuran secara in situ pada sampel air menunjukkan bahwa rentang nilai EC, TDS, pH dan suhu berturut-turut adalah (200–4120) mS/cm, (100–2060) ppt, 7,34–9,22, dan (26,8–32,6) oC. Sedangkan, hasil pengukuran sifat magnetik menunjukkan bahwa sampel sedimen Sungai Citarum bagian hilir memiliki nilai suseptibilitas magnetik frekuensi rendah (cLF) dengan rentang (65,00–173,80) x 10-8 m3/kg, sedangkan rentang nilai suseptibilitas magnetik frekuensi tinggi (cHF) adalah (64,90–165,70) x 10-8 m3/kg. Dari kedua pengukuran cLF dan cHF diperoleh rentang nilai cFD (%) sebesar 0,15–4,66. Selanjutnya, hasil analisis morfologi dari citra SEM-EDS dan analisis mineralogi berdasarkan pengukuran XRD menunjukkan dominasi jenis mineral magnetik pada sampel sedimen adalah magnetit. Mineral magnetit ini memiliki morfologi berbentuk oktahedral sebagai representasi mineral magnetik alami dan ada pula yang berbentuk spherule sebagai representasi mineral magnetik karena adanya proses oksidasi akibat kehadiran material antropogenik pada sedimen Sungai Citarum bagian hilir.

scholarly journals Study on Microstructure and Mechanical Properties of Al7068 Reinforced with Silicon Carbide and Fly Ash by Powder Metallurgy

2021 ◽  
Vol 7 (09) ◽  
pp. 47-53
Author(s):  
Md Mehtab Alam and B.S Motgi
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Fly Ash ◽  
Powder Metallurgy ◽  
Aluminum Matrix ◽  
Hydraulic Press ◽  
Powder Form ◽  
X Ray ◽  
Microstructure And Mechanical Properties ◽  
Scanning Electron

The paper deals with detailed study on microstructure and mechanical properties of aluminum 7068 reinforced with fly ash and silicon carbide by powder metallurgy, aluminum 7068, silicon carbide and fly ash were taken in powder form of required size and mixed together in varying proportion according to specification and compacted with pressure of 400MPa using hydraulic press to make samples and then samples were sintered at 600°c for 2 hours, the samples were tested for density, compressive strength, hardness and microstructure was analyzed using scanning electron microscope, energy dispersive x-ray study was carried out in order to confirm presence of silicon carbide and fly ash in aluminum matrix.

Preparation of Cu-Cr-Zr/AlN Nanocomposites and their Mechanical and Conductive Properties

2011 ◽  
Vol 239-242 ◽  
pp. 2756-2759
Author(s):  
Yong Qiang Qin ◽  
Yu Cheng Wu ◽  
Yan Wang ◽  
Yu Hong ◽  
Jing Quan Deng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Wear Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Mechanical Alloying ◽  
Room Temperature ◽  
Copper Alloys ◽  
Morphology Characterization ◽  
Conductive Properties ◽  
Conductivity Behavior

Copper and copper alloys had various applications in tremendous areas due to their unique properties, such as good conductivity, good thermal conductivity and so on. However, applications of copper and copper alloys were severely restricted as the result of the limited strength at room temperature and poor wear-resistance at high temperature. In this paper, we investigated the preparation of Cu-Cr-Zr/AlN nanocomposites by mechanical alloying process and then powder metallurgy technology. XRD and SEM were performed for the phase and morphology characterization. The conductivity properties were also tested and the results showed that Cu-Cr-Zr/AlN nanocomposites exhibited excellent conductivity behavior.

Microstructural characterization of biobased carbon foam by means of X-ray microtomography and compared to conventional techniques

RSC Advances ◽  
2016 ◽  
Vol 6 (98) ◽  
pp. 96057-96064 ◽  
Author(s):  
Juliette Merle ◽  
Pascale Sénéchal ◽  
Fabrice Guerton ◽  
Peter Moonen ◽  
Pierre Trinsoutrot ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Mercury Intrusion Porosimetry ◽  
Microstructural Characterization ◽  
Carbon Foam ◽  
X Ray ◽  
Mercury Intrusion ◽  
Scanning Electron

The objective of this work is to compare three techniques for characterizing the morphology of porous bio-based carbon foam, namely mercury intrusion porosimetry, scanning electron microscopy and X-ray microtomography.

Synthesis of Cu/Cr and Cu/Cr/W Materials by Powder Metallurgy Techniques

2018 ◽  
Vol 880 ◽  
pp. 241-247
Author(s):  
Claudiu Nicolicescu ◽  
Victor Horia Nicoară ◽  
Costel Silviu Bălulescu
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Powder Metallurgy ◽  
Chemical Composition ◽  
Electrical Properties ◽  
Mechanical Alloying ◽  
Ball Mill ◽  
Weight Percent ◽  
Scanning Electron

Alloys based on Cu/Cr and Cu/Cr/W attract the attention due to their presence in different applications that require higher electrical properties which are combined with good mechanical properties. In order to synthesis the material based on Cu/Cr and Cu/Cr/W, mechanical alloying technique was used. Four mixtures, X1 (99%CuCr), X2 (97%CuCr), X3 (94%Cu1%CrW), X4 (92%Cu3%CrW – weight percent), were prepared using a vario planetary ball mill Pulverisette 4 made by Fritsch. The mixtures obtained after 10 hours were analyzed by scanning electron microscopy (SEM). It was found that the presence of chromium and tungsten influence the morphology and the particles tend to be flat. Sinter ability and microhardness are influenced by the chemical composition of the samples.

Microstructural Characterization of Glass-to-Metal Brazed Joint

2012 ◽  
Vol 616-618 ◽  
pp. 1732-1735 ◽  
Author(s):  
Xi Hai Shen ◽  
Yu Gang Zheng ◽  
Liang Chang ◽  
Jin Jia Guo ◽  
Song Bin Ye ◽  
...  
Keyword(s):  
Thermal Power ◽  
Microstructural Characterization ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solar Thermal Power ◽  
Brazed Joints ◽  
Brazed Joint ◽  
Scanning Electron

Aiming at the glass-to-metal seals serving in the Solar Thermal Power (STP), glass-to-metal vacuum brazed joints were studied. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were performed to examine the microstructure and element contents of interface seam on the glass-to-metal vacuum brazed joints. Also, the compositional concentration of the interface seam was measured by using energy dispersive spectroscopy (EDS).

Effect of Sintering Temperature on Silver-Copper Nanopaste as High Temperature Die Attach Material

2013 ◽  
Vol 795 ◽  
pp. 47-50 ◽  
Author(s):  
Kim Seah Tan ◽  
Kuan Yew Cheong
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Sintering Temperature ◽  
Grain Structure ◽  
Binder System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Silver Copper ◽  
Die Attach ◽  
Scanning Electron

A novel stencil-printable silver-copper (Ag-Cu) nanopaste that serves as an alternative high temperature die attach material was introduced in this study. The nanopaste was made by mixing 50 nm-sized of Ag and Cu particles with an organic binder system. Sintering temperatures, up to 450°C, were used to sinter nanopaste in air and its post sintered properties were investigated. The viscosity of nanopaste was 350,000 cps and it demonstrated a shear thinning behavior. Scanning electron microscope revealed the change of grain structure with the change in the sintering temperature. Formations of Ag97Cu3 and Ag1Cu99 compounds after sintering were confirmed with X-ray diffraction; and the electrical conductivity of the sintered nanopaste was increased with the increase of the sintering temperature. The study concluded 380°C was the optimum sintering temperature to form a well sintered nanopaste.

Vacuum Breakdown Behavior of CuWCr Composites

2008 ◽  
Vol 569 ◽  
pp. 125-128
Author(s):  
Peng Xiao ◽  
Zhi Kang Fan
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Powder Metallurgy ◽  
Electrical Properties ◽  
Mechanical Alloying ◽  
Arc Erosion ◽  
Before And After ◽  
Chopping Current ◽  
Uniform Composition ◽  
Scanning Electron

The Cu20W70Cr10 composites were fabricated by two methods which are the conventional powder metallurgy, and mechanical alloying to prepare WCr compound powders, followed by sintering and infiltration. The erosion behavior of CuWCr composites under breakdown was investigated. The surfaces of the composites before and after erosion and the mechanism of arc erosion were studied by scanning electron microscopy. The results show that the CuWCr composites prepared by mechanical alloying have superfine microstructure, uniform composition and high density, thus result in good characteristics of diffusing arcs and arc eroding endurance. Arc erosion zones are dispersive and uniform on the surfaces with some flat eroding pits. The Cu20W70Cr10 composites have excellent electrical properties such as high breakdown voltage, low chopping current and long arc life.

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