Effect of Interconnectivity of Nickel on Electrical and Thermal Properties of Alumina-Ni Interpenetrating Phase Composite

2011 ◽  
Vol 239-242 ◽  
pp. 2679-2682 ◽  
Author(s):  
Rub Nawaz Shahid ◽  
Bin Awais Hasan ◽  
Fahad Ali ◽  
Naeem Ul Haq Tariq
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Impedance Spectroscopy ◽  
Electron Spectroscopy ◽  
Coefficient Of Thermal Expansion ◽  
Optimal Combination ◽  
Percolation Limit ◽  
Scanning Electron

In this work percolation range for Al2O3-Ni interpenetrating phase composite (IPC) was studied to find the optimal combination of electrical conductivity and coefficient of thermal expansion (CTE). The impedance spectroscopy and scanning electron spectroscopy were used to study the percolation limit.

Improving mechanical and thermal properties of graphite–aluminium composite using Si, SiC and eggshell particles

2019 ◽  
Vol 54 (17) ◽  
pp. 2365-2376 ◽  
Author(s):  
MO Durowoju ◽  
TB Asafa ◽  
ER Sadiku ◽  
S Diouf ◽  
MB Shongwe ◽  
...  
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Thermal Properties ◽  
Relative Density ◽  
Coefficient Of Thermal Expansion ◽  
Mechanical And Thermal Properties ◽  
Sem Images ◽  
Plasma Sintering ◽  
Low Thermal Expansion ◽  
Spark Plasma

Graphite–aluminium (Gr–Al) composites are being used for diverse engineering applications because of their light weight, good electrical conductivity and thermal properties. However, their applications are limited by high coefficient of thermal expansion and low microhardness values which can be enhanced by adding cheap and efficient fillers. This paper reports the effect of addition of eggshell (ES) particles on the properties of sintered Gr–Al-based composites. Five different composites (Gr–Al, Gr–Al  +  20 wt.%Si, Gr–Al + 20 wt.%SiC, Gr–Al + 20Si wt.% + 20 wt.%ES and Gr–Al + 20SiC wt.% + 20 wt.%ES) were sintered at a temperature of 540 ℃, holding time of 10 min, heating rate of 52 ℃/min and pressure of 50 MPa using spark plasma sintering system. The sintered samples were characterized based on morphology, microhardness, relative density, coefficient of thermal expansion and electrical conductivity. Based on SEM images, graphite particles of flake-like structure were largely undeformed while Al particles were smaller, round and irregular in shape and fairly uniformly distributed in the composites. The microhardness value of sintered Gr–Al + 20 wt.%SiC + 20 wt.%ES composite was 39.55 HV compared to 30.46 HV for Gr–Al, the least of the samples. The Gr–Al + 20 wt.%SiC + 20 wt.%ES composite also has a very low thermal expansion coefficient (0.98 × 10−5/K) but lowest electrical conductivity at temperature beyond 150 ℃. Highest densification and minimum relative density (94%) were obtained in Gr–Al + 20 wt.%Si + 20 wt.%ES composite. These enhanced performances are largely due to the incorporation of ES particles. This study therefore demonstrated that ESs particles enhanced microhardness and lowered thermal expansion of Gr–Al-based composites which have promising applications in industries especially for thermal management.

Electrical conductivity changes in bulk Sn, and eutectic Sn-Ag in bulk and in joints, from aging and thermal shock

2005 ◽  
Vol 20 (2) ◽  
pp. 364-374 ◽  
Author(s):  
F. Guo ◽  
J.G. Lee ◽  
T. Hogan ◽  
K.N. Subramanian
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Thermal Shock ◽  
Intermetallic Compounds ◽  
Damage Accumulation ◽  
Coefficient Of Thermal Expansion ◽  
Substrate Interface ◽  
Effects Of Aging

Electrical conductivity of electronic interconnects made with Sn-based solders undergo a significant amount of deterioration during service. Several factors, such as anisotropy of Sn, coefficient of thermal expansion mismatches between the entities that make up the joint, and growth of intermetallic compounds present within the solder and solder/substrate interface, may contribute to the damage accumulation during thermal excursions and cause deterioration of properties. This study dealing with effects of aging and thermal shock on electrical conductivity, carried out with bulk Sn, and eutectic Sn–Ag in bulk and joint configurations, is aimed at evaluating the roles of the above factors on the deterioration of electrical conductivity from these thermal excursions.

Effect of Al2O3 on the Electrical Conductivity and Structural Study in MgI2-Mg3(PO4)2 Based Solid Electrolyte

2013 ◽  
Vol 701 ◽  
pp. 150-153
Author(s):  
A. Aziz ◽  
M.M. Mahat ◽  
A.H. Ahmad
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Scanning Electron Microscopy ◽  
Impedance Spectroscopy ◽  
Field Emission ◽  
Weight Percent ◽  
Binary Compound ◽  
Maximum Conductivity ◽  
Enhanced Conductivity ◽  
Scanning Electron

The effect of filler to the binary compound of Magnesium Iodide ( MgI2) and Magnesium Phosphate (Mg3(PO4)2is investigated. A small amount Alumina (Al2O3) filler in the range of 2-10 weight percent is added to the optimum composition with maximum conductivity of binary compound 0.7 Mg3(PO4)2and 0.3 MgI2.The electrical conductivity of theMgI2- Mg3(PO4)2- Al2O3measured using the impedance spectroscopy (IS) method and result shows that the electrical conductivity of the compound has improved up to 9.84x10-4Scm-1. Field Emission Scanning Electron Microscopy (FESEM) images show some changes in the morphology after introduce the filler. The samples with filler showsnano flakes like structure with some space createdallowing the Mg2+cations to migrate that lead to enhanced conductivity.

Evaluation of Coefficient of Thermal Expansion of Zirconium by Using Dilatometer & Ansys

2018 ◽  
Vol 1148 ◽  
pp. 128-135
Author(s):  
Repalle Jithendra Kumar ◽  
B.V.S. Raghu Vamsi ◽  
T. Siva Krishna ◽  
D. Tarun ◽  
M. Kamal Tej
Keyword(s):  
Thermal Expansion ◽  
Corrosion Resistance ◽  
Thermal Properties ◽  
Nuclear Reactors ◽  
Coefficient Of Thermal Expansion ◽  
Zirconium Alloys ◽  
Nuclear Technology ◽  
High Corrosion Resistance ◽  
Weight Percentage ◽  
Water Reactors

Zirconium alloys are solid solutions of zirconium or other metals. Zirconium has very low absorption cross-section of thermal neutrons. Zirconium has high corrosion resistance, ductility and hardness. Zirconium is mainly used as a good refractory metal. Zirconium can be manufactured by using standard fabrication techniques. In the present scenario zirconium alloys are used in water reactors for the cladding of fuel rods in nuclear reactors in nuclear technology. We use the composition of zirconium alloys as more than 94.5 weight percentage of zirconium and less than 2.45 weight percentage of copper which are added to improve mechanical, thermal properties and corrosion resistance. This paper first focuses on the study of thermal properties of Zirconium. And this particularly concentrated on variation of Coefficient of Thermal Expansion by varying temperatures by using Dilatometer and as well as ANSYS

Synthesis and processing of nanocrystalline Ag–Fe–Ni for low thermal expansion–high conductivity thermal management applications

2001 ◽  
Vol 16 (2) ◽  
pp. 340-343 ◽  
Author(s):  
J. Stolk ◽  
M. Gross ◽  
D. Stolk ◽  
A. Manthiram
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Metal Ion ◽  
Coefficient Of Thermal Expansion ◽  
Thermomechanical Analysis ◽  
Nominal Composition ◽  
Two Phase ◽  
X Ray ◽  
Fine Grained ◽  
Low Thermal Expansion

Nanocrystalline Ag–Fe–Ni powders were produced by a reduction of the aqueous metal ion solutions with sodium borohydride and then converted to fine-grained silver–Invar alloys that offer attractive thermal, electrical, and mechanical properties. The samples were characterized by x-ray diffraction, scanning electron microscopy, wavelength dispersive x-ray spectrometry, thermomechanical analysis, microhardness measurements, and electrical conductivity measurements; thermal conductivity was estimated using the Wiedemann–Franz law. Sintering of a specimen with a nominal composition of 60 wt% Ag–25.6 wt% Fe–14.4 wt.% Ni led to the formation of a two-phase silver–Invar alloy with a grain size of approximately 2 μm, a hardness of 133 HK200g, coefficient of thermal expansion of 12.44 × 10−6 / °C, and electrical conductivity of 2.13 × 105 (Ω cm) −1.

Effect of aggregate type on linear thermal expansion of self-consolidating concrete at elevated temperatures

2012 ◽  
Vol 19 (3) ◽  
pp. 259-269 ◽  
Author(s):  
Tayfun Uygunoğlu ◽  
İlker Bekir Topçu
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Elevated Temperatures ◽  
Coefficient Of Thermal Expansion ◽  
Linear Thermal Expansion ◽  
Thermal Tests ◽  
Linear Change ◽  
Volcanic Tuff ◽  
Self Consolidating Concrete ◽  
Cement Ratio

AbstractIn this study, the effects of aggregate type on the coefficient of thermal expansion of self-consolidating concrete (SCC) produced with normal and lightweight (porous) aggregate (SCLC) were investigated. In experiments, three aggregate types, gravel, volcanic tuff, and diatomite, were used. Different combinations of water/cement ratio and superplasticizer dosage levels were prepared for the SCC and SCLC mixtures. Thermal tests were performed to accurately characterize the coefficient of thermal expansion (CTE) of SCC and SCLC aged 28 days using the dilatometer. The CTEs of SCC and SCLC were defined by measuring the linear change in length of concrete specimens subjected to a range of temperatures from 20°C to 1000°C. The results, in general, showed that SCLC has a lower CTE than that of SCC above 100°C. Moreover, CTE values of SCC and SCLC were decreased with increase in porous structure. The aggregate type has significant influence on the thermal properties of SCC.

Comparison study of carbon black (CB) used as conductive filler in epoxy and polymethylmethacrylate (PMMA)

2016 ◽  
Vol 36 (4) ◽  
pp. 391-398 ◽  
Author(s):  
Jin-Luen Phua ◽  
Pei-Leng Teh ◽  
Supri Abdul Ghani ◽  
Cheow-Keat Yeoh
Keyword(s):  
Thermal Stability ◽  
Electrical Conductivity ◽  
Fracture Toughness ◽  
Thermal Expansion ◽  
Carbon Black ◽  
Coefficient Of Thermal Expansion ◽  
Conductive Filler ◽  
Filler Loading ◽  
Comparison Study ◽  
Thermoset Epoxy

Abstract A comparison study between carbon black (CB) filled thermoset (epoxy) and thermoplastic, polymethylmethacrylate (PMMA), was done in this research. CB was introduced as the conductive filler in epoxy and PMMA at different filler loading, which ranged from 5 vol.% to 20 vol.%. The physical, mechanical, electrical and thermal stability properties were investigated. The incorporation of CB into both epoxy and PMMA increased the density, improved the thermal stability and electrical conductivity of the composites, reduced the coefficient of thermal expansion and weakened the flexural and fracture toughness properties of the composites.

Effect of Bi2O3 on Thermal Properties of Barium-Free Glass-Ceramic Sealants in the CaO-MgO-B2O3-Al2O3-SiO2 System

2015 ◽  
Vol 659 ◽  
pp. 180-184 ◽  
Author(s):  
Pornchanok Lawita ◽  
Apirat Theerapapvisetpong ◽  
Sirithan Jiemsirilers
Keyword(s):  
Thermal Expansion ◽  
Thermal Properties ◽  
Thermal Treatment ◽  
Glass Ceramic ◽  
Mechanical Stability ◽  
Coefficient Of Thermal Expansion ◽  
Softening Temperature ◽  
X Ray Diffraction ◽  
Free Glass

Barium-free glass-ceramic sealants for the planar solid oxide fuel cell (pSOFC) have attracted considerable attention to avoid the crystallization of the high coefficient of thermal expansion (CTE) BaCrO4; reaction product at the interface between barium-containing glass-ceramic sealants and Crofer22 APU interconnect, which decreases the long-term mechanical stability of the sealant. In this study, Barium-free glass-ceramic sealants in the CaO-MgO-B2O3-Al2O3-SiO2 system with varying amounts of Bi2O3 from 0 to 10 wt. % were prepared by conventional melting and their thermal properties were investigated. The glass transition temperature (Tg), dilatometric softening temperature, and coefficient of thermal expansion (CTE) were determined by a dilatometer. The Tg, onset of crystallization (Tx) and crystallization temperature (Tc) were obtained from DTA. Results of phase analysis by X–ray diffraction of glasses after thermal treatment at 900 oC for 2 h indicated that the major phase of all glasses was diopside (MgCaSi2O6) and minor phases were åkermanite (Ca2MgSi2O7) and forsterite (Mg2SiO4). The Tg of the fabricated glasses tended to decrease with increasing Bi2O3 content while the CTE of glasses increased after the thermal treatment and was in the range of requirement for SOFC sealant.

IMPROVEMENT OF MECHANICAL AND THERMAL PROPERTIES OF CFRP LAMINATES USING MICRO-FIBRILLATED CELLULOSE

2012 ◽  
Vol 06 ◽  
pp. 622-627 ◽  
Author(s):  
HYOJIN KIM ◽  
TADASHI SUZUKI ◽  
KENICHI TAKEMURA
Keyword(s):  
Thermal Expansion ◽  
Glass Transition ◽  
Thermal Properties ◽  
Carbon Fiber ◽  
Coefficient Of Thermal Expansion ◽  
Flexural Modulus ◽  
Mechanical And Thermal Properties ◽  
Flexural Test ◽  
Cfrp Laminates ◽  
Carbon Fiber Epoxy

The aim of this study is improvement of mechanical and thermal properties of plain woven carbon fiber (CF) reinforced epoxy with addition of MFC as the additive. Carbon fiber/epoxy laminates with addition 0.3, 0.5, 0.7 and 1wt% of MFC were characterized by flexural test, DSC and TMA. The result represented that the flexural strength improved slightly at 0.3 and 0.5 wt% of MFC, but flexural modulus was not changed, respectively. The glass transition temperature of MFC-CFRP laminates showed the increase according to increase of MFC addition at 0.7 and 1.0 wt%. The coefficient of thermal expansion was decrease by 0.7 wt% of MFC addition.

Thermal, Electrical and Physical Properties of Recycled Copper Filled Epoxy Composites

2012 ◽  
Vol 620 ◽  
pp. 208-212
Author(s):  
Mohamd Nur Fuadi Pargi ◽  
Pei Leng Teh ◽  
Salmah Husseinsyah ◽  
Cheow Keat Yeoh
Keyword(s):  
Electrical Conductivity ◽  
Thermal Expansion ◽  
Physical Properties ◽  
Volume Fraction ◽  
Epoxy Composite ◽  
Coefficient Of Thermal Expansion ◽  
Filler Loading ◽  
Epoxy Composites ◽  
Milling Machine

The effect of recycled copper filled epoxy composites on thermal, electrical and physical properties were investigated. The recycled copper was collected as a waste from the milling machine. The recycled copper filled epoxy composite was mixed using mechanical stirrer. The effect of volume fraction of recycled copper of the epoxy composites were studied based on the coefficient of thermal expansion (CTE), electrical conductivity hardness and density. Incorporation of recycled copper has decreased the CTE of the composites. The electrical conductivity, hardness and density of the composites increased with increasing of volume fraction and filler loading.

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