scholarly journals Investigation on Strength and Microstructural Evolution of Porous Cu/Cu Brazed Joints Using Cu-Ni-Sn-P Filler

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 416
Author(s):  
Mian Muhammad Sami ◽  
Tuan Zaharinie ◽  
Farazila Yusof ◽  
Tadashi Ariga
Keyword(s):  
Surface Hardening ◽  
Filler Metal ◽  
Joint Interface ◽  
X Ray Diffraction ◽  
Cooling Device ◽  
X Ray ◽  
Porous Copper ◽  
Brazed Joints ◽  
Increasing Temperature ◽  
Integral Feature

Porous Copper (Cu) was brazed to Cu plates using Cu-9.7Sn-5.7Ni-7P amorphous filler metal. The effects of brazing parameters on the porous Cu and brazed joints were investigated. The furnace brazing temperatures employed were 660 °C and 680 °C, and the holding times were 10 and 15 min. After brazing, the microstructure was analyzed using Scanning Electron Microscope (SEM) equipped with Electron Dispersive X-ray Spectroscope (EDS). SEM results showed that the thickness of the brazed seam at the base joint decreased with increasing temperature and time. At low brazing temperature, microvoids and cracks were observed at the joint interface. The microvoids and cracks disappeared in the sample brazed at 680 °C for 15 min, and higher diffusion of the filler was noted in the overall bonded region. The formation of Cu-P, Cu-Ni, and Ni-Sn phases at the joint interface was validated using X-ray diffraction. The phases formed increased the hardness of the brazed joints and porous Copper. It was observed that the rigidity of porous Copper tends to increase due to surface hardening effects. The rigidity of porous Cu after brazing is important in ensuring minimal deformation during cooling device servicing, which is an integral feature of prospect product development.

scholarly journals Evaluation of Biomedical Ti/ZrO2 Joint Brazed with Pure Au Filler: Microstructure and Mechanical Properties

Metals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 526
Author(s):  
Yuzhen Lei ◽  
Hong Bian ◽  
Wei Fu ◽  
Xiaoguo Song ◽  
Jicai Feng ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Energy Dispersive Spectrometry ◽  
Filler Metal ◽  
Interfacial Microstructure ◽  
Holding Time ◽  
X Ray Diffraction ◽  
X Ray ◽  
Medical Products ◽  
Metallurgical Bonding ◽  
Brazed Joints

Titanium and zirconia (ZrO2) ceramics are widely used in biomedical fields. This study aims to achieve reliable brazed joints of titanium/ZrO2 using biocompatible Au filler for implantable medical products. The effects of brazing temperature and holding time on the interfacial microstructures and mechanical properties of titanium/Au/ZrO2 joints were fully investigated by scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray diffraction (XRD). The results indicated that the typical interfacial microstructure of the titanium/Au/ZrO2 joint was titanium/Ti3Au layer/TiAu layer/TiAu2 layer/TiAu4 layer/TiO layer/ZrO2 ceramic. With an increasing brazing temperature or holding time, the thickness of the Ti3Au + TiAu + TiAu2 layer increased gradually. The growth of the TiO layer was observed, which promoted metallurgical bonding between the filler metal and ZrO2 ceramic. The optimal shear strength of ~35.0 MPa was obtained at 1150 °C for 10 min. SEM characterization revealed that cracks initiated and propagated along the interface of TiAu2 and TiAu4 reaction layers.

scholarly journals Research on the Physical Characteristics of Hot-Pressed Sintering Preparing Self-Fluxing Filler by X-Ray Diffraction

2021 ◽  
Vol 2083 (2) ◽  
pp. 022087
Author(s):  
Xiupeng Li ◽  
Weimin Long ◽  
Yuanxun Shen ◽  
Sujuan Zhong ◽  
Yinyin Pei ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Joint Strength ◽  
Filler Metal ◽  
Low Cost ◽  
Metal Ring ◽  
Joint Interface ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metal Rings ◽  
Al Matrix

Abstract In this paper, Al-12Si self-fluxing filler metal ring was prepared with Al-12Si alloying powders and KAlF4 flux by hot pressed sintering (HPS) method. The microstructure and mechanical properties of the brazing alloy and the brazed 3003 aluminum alloy joint were investigated. The results showed that Al-12Si self-fluxing filler metal ring could be successfully obtained by HPS at 470°C using a pressure of 300MPa. The prepared filler metal ring was dense and defect-free and the microstructure was mainly composed of Si phase with KAlF4 flux grain uniformly distributed in the Al matrix. The 3003 aluminum alloy joint interface brazed by the prepared filler metal was also well bonded and no pore and defect was found. A quite high joint strength of 75MPa was obtained which is equal to the strength of joint brazed using commercial Al-Si self-fluxing wires prepared by hot extrude method. The results revealed that the filler metal rings fabricated by HPS process had great potentiality in brazing of aluminum alloy especially for the Al-Al pipes joining due to its high joint strength, low cost and the convenience for industrial application.

Transient liquid phase bonding of Cu and Al using metallic particles interlayers

2021 ◽  
pp. 095440542098823
Author(s):  
Alireza Zaheri ◽  
Mohammadreza Farahani ◽  
Alireza Sadeghi ◽  
Naser Souri
Keyword(s):  
Liquid Phase ◽  
Mechanical Test ◽  
Transient Liquid Phase ◽  
Transient Liquid Phase Bonding ◽  
Joint Interface ◽  
Test Results ◽  
X Ray Diffraction ◽  
X Ray ◽  
Metallic Particles ◽  
Powder Interlayer

The bonding strength, and microstructures of Cu and Al couples using metallic powders as interlayer during transient liquid phase bonding (TLP bonding) were investigated. The interfacial morphologies and microstructures were studied by scanning electron microscopy equipped with energy dispersive X-ray spectroscopy, and X-ray diffraction. First, to explore the optimum bonding time and temperature, nine samples were bonded without interlayers in a vacuum condition. Mechanical test results indicated that bonding at 560°C in 20 min returns the highest bond strength (84% of Al). This bonding condition was used to join ten samples with powder interlayers. Powders were prepared by mixing different combinations of Cu, Al (+Fe nanoparticles) and Zn. In the bonding zone, different Cu9Al4, CuAl, and CuAl2 intermetallic co-precipitate. The strongest bonding is formed in the sample with the 70Al (+Fe)-30Cu powder interlayer. Powder interlayers present thinner and more uniform intermetallic layers at the joint interface.

Polydomain Structure of Epitaxial PbTiO3 films on MgO

1997 ◽  
Vol 493 ◽  
Author(s):  
S. P. Alpay ◽  
A. S. Prakash ◽  
S. Aggarwal ◽  
R. Ramesh ◽  
A. L. Roytburd ◽  
...  
Keyword(s):  
Domain Structure ◽  
Pulsed Laser ◽  
Laser Deposition ◽  
X Ray Diffraction ◽  
X Ray ◽  
Theoretical Predictions ◽  
The Stability ◽  
Increasing Temperature ◽  
Stable Domains ◽  
Domain Stability

ABSTRACTA PbTiO3(001) film grown on MgO(001) by pulsed laser deposition is examined as an example to demonstrate the applications of the domain stability map for epitaxial perovskite films which shows regions of stable domains and fractions of domains in a polydomain structure. X-ray diffraction studies indicate that the film has a …c/a/c/a… domain structure in a temperature range of °C to 400°C with the fraction of c-domains decreasing with increasing temperature. These experimental results are in excellent agreement with theoretical predictions based on the stability map.

scholarly journals Structural and thermoelectric properties of the Pr2Zr2O7 compound

2019 ◽  
pp. 4-9
Author(s):  
Adolfo Quiroz-Rodríguez ◽  
Cesia Guarneros-Aguilar ◽  
Ricardo Agustin-Serrano
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Thermoelectric Properties ◽  
Crystal Size ◽  
Ambient Pressure ◽  
X Ray Diffraction ◽  
X Ray ◽  
Increasing Temperature ◽  
Thermal Stability Of ◽  
Scanning Electron

In this research, it is presented a detailed study of the structural and thermoelectric properties of the pyrochlore zirconium Pr2Zr2O7 compound prepared by solid-state reaction (SSR) in air at ambient pressure. The synthesized sample was characterized using powder X-ray diffraction. The thermal stability of the thermoelectric compound (TE) Pr2Zr2O7 was tested by thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Scanning electron microscopy shows that the crystal size varies between 0.69 and 2.81μm. Electrical conductivity (\sigma) of the sample calcined at 1400 °C presented values increase irregularly with the increasing temperature from 0.001 to 0.018 S cm-1 as expected in a semiconductor material. The thermal conductivity is lower than 0.44 - 775 W m-1 K-1 which is quite anomalous in comparison with the thermal conductivity of other oxides.

Ferromagnetic properties and Nanocrystallization behavior of Amorphous (Fe0.99Mo0.01)78Si9B13 Ribbons

2001 ◽  
Vol 674 ◽  
Author(s):  
Xiang-Cheng Sun ◽  
J. A. Toledo ◽  
S. Galindo ◽  
W. S. Sun
Keyword(s):  
Amorphous Phase ◽  
Magnetic Ordering ◽  
Metastable Phases ◽  
X Ray Diffraction ◽  
Ferromagnetic Properties ◽  
X Ray ◽  
Diffraction Patterns ◽  
Optimum Annealing Temperature ◽  
Increasing Temperature ◽  
Differential Scanning Calorimeters

ABSTRACTFerromagnetic properties and nanocrystallization process of soft ferromagnetic (Fe0.99Mo0.01)78Si9B13 ribbons are studied by transmission electron microscope (TEM), X-ray diffraction (XRD), Mössbauer spectroscopy (MS), differential scanning calorimeters (DSC) and magnetization measurements. The Curie and crystallization temperature are determined to be TC=665K and Tx = 750K, respectively. The Tx value is in well agreement with DSC measurement results. X-ray diffraction patterns had shown a good reconfirm of two metastable phases (Fe23B6, Fe3B) were formed under in-situ nanocrystallization process. Of which these metastable phases embedded in the amorphous matrix have a significant effect on magnetic ordering. The ultimate nanocrystalline phases of α-Fe (Mo, Si) and Fe2B at optimum annealing temperature had been observed respectively. It is notable that the magnetization of the amorphous phase decreases more rapidly with increasing temperature than those of nanocrystalline ferromagnetism, suggesting the presence of the distribution of exchange interaction in the amorphous phase or high metalloid contents.

MAGHETOTHERMO POWER OF ZnO FILMS

2005 ◽  
Vol 19 (01n03) ◽  
pp. 651-653
Author(s):  
W. L. WANG ◽  
L. LI ◽  
K. J. LIAO ◽  
J. ZHANG ◽  
R. J. ZHANG ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thermoelectric Power ◽  
Substrate Surface ◽  
Zno Films ◽  
X Ray Diffraction ◽  
Electrical Measurements ◽  
X Ray ◽  
Increasing Temperature ◽  
The Magnetic Field ◽  
Orientation Growth

The Magnetothermoelectric and thermoelectric power of nano- ZnO films was investigated. The ZnO films in this study were prepared by DC reactive sputtering using a Zn target (99.99%) containing AL of 1.5%. The films obtained were characterized by SEM, x-ray diffraction, optical and electrical measurements. It was found that the sputtering ZnO films were highly orientation growth with the c-axis perpendicular to the substrate surface. The measurements showed that there was a striking seebeck effect in the ZnO films, and their thermoelectric power was linearly increased with increasing temperature. The experimental results were also demonstrated that the thermoelectric power was degraded under the magnetic field. This finding may ascribe to the magneto resistive effect.

Structural, morphological, and magnetic study of nanocrystalline cobalt-copper powders synthesized by the polyol process

1995 ◽  
Vol 10 (6) ◽  
pp. 1546-1554 ◽  
Author(s):  
G.M. Chow ◽  
L.K. Kurihara ◽  
K.M. Kemner ◽  
P.E. Schoen ◽  
W.T. Elam ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Face Centered Cubic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Copper Powders ◽  
Face Centered ◽  
Increasing Temperature ◽  
X Ray Absorption

Nanocrystalline CoxCu100−x (4 ⋚ x ⋚ 49 at. %) powders were prepared by the reduction of metal acetates in a polyol. The structure of powders was characterized by x-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), extended x-ray absorption fine structure (EXAFS) spectroscopy, solid-state nuclear magnetic resonance (NMR) spectroscopy, and vibrating sample magnetometry (VSM). As-synthesized powders were composites consisting of nanoscale crystallites of face-centered cubic (fcc) Cu and metastable face-centered cubic (fcc) Co. Complementary results of XRD, HRTEM, EXAFS, NMR, and VSM confirmed that there was no metastable alloying between Co and Cu. The NMR data also revealed that there was some hexagonal-closed-packed (hcp) Co in the samples. The powders were agglomerated, and consisted of aggregates of nanoscale crystallites of Co and Cu. Upon annealing, the powders with low Co contents showed an increase in both saturation magnetization and coercivity with increasing temperature. The results suggested that during preparation the nucleation of Cu occurred first, and the Cu crystallites served as nuclei for the formation of Co.

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).

Raman Spectroscopic and X-ray Diffraction Studies on Concentrated Aqueous Zinc (II) Bromide Solution at High Temperatures

1992 ◽  
Vol 47 (3) ◽  
pp. 485-492 ◽  
Author(s):  
Toshiyuki Takamuku ◽  
Mikito Ihara ◽  
Toshio Yamaguchi ◽  
Hisanobu Wakita
Keyword(s):  
Diffraction Data ◽  
Broad Band ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
Raman Spectroscopic ◽  
X Ray Scattering ◽  
Bromide Solution ◽  
Stretching Vibration ◽  
Increasing Temperature

Abstract Raman and X-ray scattering experiments have been performed on an aqueous zinc (II) bromide solution with molar ratio [ H2 0] / [ ZnBr2 ] =10 at 25 to 140 °C. The intensity of the totally symmetric Zn - Br stretching vibration (ν1) for the dibromozinc(II) complex increased with increasing temperature while that for the tetrabromo complex decreased. A broad band assigned to the symmetric Zn - O stretching vibration ( ν1 ) for the aqua zinc (II) ion decreased in intensity with increasing temperature. The X-ray diffraction data revealed that the average number of the Zn - Br interactions within the zinc (II) bromo complexes does not change with temperature, whereas the number of Br ··· Br nonbonding interactions within the complexes decreases from 1.8 at 25 °C to 1.5 at 100 °C. From both Raman and X-ray data it is concluded that with increasing temperature the dibromo species is favored, whereas the tetrabromo and aqua zinc(II) species are unstable in the solution. The analysis of the X-ray diffraction data has shown that the mean Zn - Br bond length within the zinc (II) bromo complexes shortens gradually with increasing temperature, accompanied with an increase in the interligand Br ···Br distance. This finding suggests that the Br - Zn - Br bond angle increases with decreasing Zn - Br distance for the lower zinc(II) bromo complexes. The equilibrium shift of the zinc (II) bromo complexes with temperature is discussed on the basis of ion-ion, ion-water, and water-water interactions

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