scholarly journals Intermetallic Bonding for High-Temperature Microelectronics and Microsystems: Solid-Liquid Interdiffusion Bonding

2018 ◽  
Author(s):  
Knut E. Aasmundtveit ◽  
Thi-Thuy Luu ◽  
Hoang-Vu Nguyen ◽  
Andreas Larsson ◽  
Torleif A. Tollefsen
Keyword(s):  
High Temperature ◽  
Solid Liquid

Two-Dimensional Transient Heat Transfer Model for High-Temperature Laser-Scanning Confocal Microscopy

2021 ◽  
Author(s):  
Dasith Liyanage ◽  
Suk-Chun Moon ◽  
Ajith S. Jayasekare ◽  
Abheek Basu ◽  
Madeleine Du Toit ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Phase Transformation ◽  
High Temperature ◽  
Laser Scanning ◽  
Laser Scanning Confocal Microscopy ◽  
Transfer Model ◽  
Two Dimensional ◽  
Scanning Confocal Microscopy ◽  
Solid Liquid Interface ◽  
Solid Liquid

Abstract High-temperature laser-scanning confocal microscopy (HT-LSCM) has proven to be an excellent experimental technique through in-situ observations of high temperature phase transformation to study kinetics and morphology using thin disk steel specimens. A 1.0 kW halogen lamp, within the elliptical cavity of the HT-LSCM furnace radiates heat and imposes a non-linear temperature profile across the radius of the steel sample. This local temperature profile when exposed at the solid/liquid interface determines the kinetics of solidification and phase transformation morphology. A two-dimensional numerical heat transfer model for both isothermal and transient conditions is developed for a concentrically solidifying sample. The model can accommodate solid/liquid interface velocity as an input parameter under concentric solidification with cooling rates up to 100 K/min. The model is validated against a commercial finite element analysis software package, Strand7, and optimized with experimental data obtained under near-to equilibrium conditions. The validated model can then be used to define the temperature landscape under transient heat transfer conditions.

High temperature investigation of the solid/liquid transition in the PuO2–UO2–ZrO2 system

2015 ◽  
Vol 467 ◽  
pp. 660-676 ◽  
Author(s):  
A. Quaini ◽  
C. Guéneau ◽  
S. Gossé ◽  
B. Sundman ◽  
D. Manara ◽  
...  
Keyword(s):  
High Temperature ◽  
Liquid Transition ◽  
Solid Liquid ◽  
Zro2 System

Au-Sn SLID bonding for high temperature applications

2011 ◽  
Vol 2011 (HITEN) ◽  
pp. 000058-000067 ◽  
Author(s):  
Torleif André Tollefsen ◽  
Andreas Larsson ◽  
Knut Aasmundtveit
Keyword(s):  
High Temperature ◽  
Cross Sections ◽  
Cost Effective ◽  
Stress Tests ◽  
Packaging System ◽  
Bonding Properties ◽  
Bond Interface ◽  
Processing Techniques ◽  
Solid Liquid ◽  
Interconnect Technology

Au-Sn solid-liquid-interdiffusion (SLID) bonding is a novel and promising interconnect technology for high temperature (HT) applications. In combination with Silicon Carbide (SiC) devices, Au-Sn SLID has the potential of being a key technology for the next generation of innovative, cost effective and environmentally friendly drilling and well intervention systems for the oil industry. However, limited knowledge about Au-Sn SLID bonding for combined HT and high power applications is a major restriction to fully realize the high temperature potential of SiC devices. This paper presents a comprehensive study of fluxless Au-Sn SLID bonding. Two different processing techniques – electroplating of Au / Sn layers and sandwiching of eutectic Au-Sn preform between electroplated Au layers – have been studied in a simplified metallization system. The latter process was further investigated in two different Cu / Si3N4 / Cu / NiP / Au-Sn / Ni / Ni2Si / SiC systems (different Au-layer thickness). Die shear tests and cross-sections have been performed on “as bonded”, thermally cycled and thermally aged samples to characterize the bonding properties associated with the different processing techniques, metallization schemes and environmental stress tests. A uniform Au-rich bond interface is produced (the ζ phase with a melting point of 522 °C). The importance of excess Au on both substrate and chip side in the final bond is demonstrated. It is shown that Au-Sn SLID can absorb thermo-mechanical stresses induced by large CTE mismatches (up to 12 ppm/K) in a packaging system during HT thermal cycling. The bonding strength of Au-Sn SLID is shown to be superb, exceeding 78 MPa. Importantly, Au-Sn SLID is shown to be an excellent interconnect technology for HT packaging.

An Attempt to Provide a Unified Treatment of Tribology Through Load Carrying Capacity, Transport, and Continuum Mechanics

1980 ◽  
Vol 102 (2) ◽  
pp. 153-164 ◽  
Author(s):  
M. Godet ◽  
D. Play ◽  
D. Berthe
Keyword(s):  
High Temperature ◽  
Continuum Mechanics ◽  
Carrying Capacity ◽  
Load Carrying Capacity ◽  
Third Body ◽  
Continuum Approach ◽  
Load Carrying ◽  
Solid Liquid ◽  
Film Lubrication ◽  
The Continuum

This paper attempts to give a unified treatment of experiments obtained with solid, liquid and boundary lubricants, different plastics, high temperature steels and elastomers. The argument is centered around third body role, load-carrying capacity, transport and continuum mechanics. This study suggests that an extension to general tribology of the continuum approach used in full film lubrication could be profitable.

Heat Transfer Enhancement of Phase Change Materials (PCMs) in Low and High Temperature Thermal Storage by Using Porous Materials

2010 ◽  
Author(s):  
C. Y. Zhao ◽  
D. Zhou ◽  
Z. G. Wu
Keyword(s):  
Heat Transfer ◽  
High Temperature ◽  
Phase Change ◽  
Porous Materials ◽  
Phase Change Materials ◽  
Heat Transfer Performance ◽  
Expanded Graphite ◽  
Metal Foams ◽  
Transfer Performance ◽  
Solid Liquid

In this paper the solid/liquid phase change heat transfer in porous materials (metal foams and expanded graphite) at low and high temperatures is experimentally investigated, in an attempt to examine the feasibility of using metal foams to enhance the heat transfer capability of phase change materials for use with both the low and high temperature thermal energy storage systems. In this research, the organic commercial paraffin wax and inorganic hydrate calcium chloride hydrate salts were employed as the low-temperature materials, while the sodium nitrate is used as the high-temperature PCM in the experiment. The heat transfer characteristics of these PCMs embedded with open-cell metal foams were studied experimentally. The composites of paraffin and expanded graphite with different graphite mass ratios, namely, 3%, 6% and 9%, were also made and the heat transfer performances of these composites were tested and compared with metal foams. Overall metal foams can provide better heat transfer performance than expanded graphite due to their continuous inter-connected structures. But the porous materials can suppress the natural convection effect in liquid zone, particularly for the PCMs with low viscosities, thereby leading to the different heat transfer performance at different regimes (solid, solid/liquid and liquid regions). This implies that the porous materials don’t necessarily mean they can always enhance heat transfer in every regime.

Studying on High Temperature Thermoplastic of High Carbon Steel

2014 ◽  
Vol 809-810 ◽  
pp. 384-389
Author(s):  
Lang He ◽  
Yu Tang
Keyword(s):  
Electron Microscope ◽  
High Temperature ◽  
Melting Point ◽  
Liquid Phase ◽  
Energy Dispersive Spectrometer ◽  
High Carbon Steel ◽  
Optical Microscope ◽  
High Carbon ◽  
Solid Liquid ◽  
Scanning Electron

High temperature thermoplastic of 50Mn2V casting slab was tested by Gleeble-1500 thermal simulator machine. The morphology, microstructure and composition of fracture surfacewere observed and analyzed by optical microscope (OM), scanning electron microscope (SEM) and energy dispersive spectrometer (EDS).The results show that, there are two brittle temperature zones of 50Mn2V casting slab at the temperature of 600~950°C and 1300~1465°C, respectively, The section shrinkaging rate is less than 60%. The fracture mode changes from mixed one dominated by intergranular to toughness transgranular one with the increase of temperature at the range of 600~1250°C. However, the fracture is along with the solid-liquid phase at the range of 1300°C~ melting point.

Real-Time Observation of High Temperature Interface between SiC Substrate and Solution during Dissolution of SiC

2013 ◽  
Vol 740-742 ◽  
pp. 35-38 ◽  
Author(s):  
Sakiko Kawanishi ◽  
Takeshi Yoshikawa ◽  
Kazuki Morita
Keyword(s):  
High Temperature ◽  
Real Time ◽  
Back Surface ◽  
Lateral Direction ◽  
Digital Microscope ◽  
Time Observation ◽  
A New Technique ◽  
Solid Liquid Interface ◽  
Solid Liquid ◽  
Real Time Observation

Precise morphological control of the interface between SiC and solution during the solution growth of SiC is crucial for obtaining high quality crystals with fewer defects and less step bunching. In this paper, a new technique for real-time observation of the high temperature interface between SiC and solution through the back surface of SiC was developed by focusing on the “wide” bandgap of SiC. Real-time observation of the interface during dissolution of SiC into an Fe-Si solvent alloy was carried out using a digital microscope, and the submicron-height structure of the solid-liquid interface was clearly observed at up to 1773 K. Interface morphologies, such as numerous hexagonal pits which were present at the initial stage of dissolution, followed by preferential dissolution in the lateral direction, were observed.

scholarly journals The Simulation of the Preparation of the Ingot With Liquid Core

2021 ◽  
Author(s):  
yongqiang wu ◽  
Zhi-ren Sun ◽  
Kaikun Wang
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Liquid Phase ◽  
Solid Phase ◽  
Liquid Core ◽  
Phase Region ◽  
Simulation Results ◽  
Solid Liquid ◽  
Deform 3D ◽  
Ultra High Temperature

Abstract During the preparation of the ingot with liquid core in the early stage, the finite element models of the solidification and the ultra-high temperature demoulding were established in DEFORM-3D. The thermophysical properties of ASSAB 718 with the variations of C, Mn and Cr were calculated in JMatPro®. The material database was imported into DEFORM-3D. Through the analysis of the finite element simulation results, we obtained the influence of three main elements C, Mn and Cr contents on the size of the solid-phase region, the liquid-phase region and the solid-liquid two-phase region in the ingot. We optimized the composition of the material to get a wide solid-liquid phase range. The high carbon, the medium manganese and the high chromium contents were beneficial to form the liquid core. Based on the method of the solidification time, the algorithm was programmed by the python language. We analyzed the influence of the three elements C, Mn, and Cr on the concentration distribution based on the temperature field data, which were obtained by DEFORM-2D after the solidification and the ultra-high temperature demoulding. According to the simulation results, we found that the region prone to negative segregation.

IV. Order–disorder transitions: solid state kinetics, thermal analyses, X-ray diffraction and electrical conductivity studies in the Ag2SO4–K2SO4 system

1985 ◽  
Vol 63 (2) ◽  
pp. 324-328 ◽  
Author(s):  
M. Sunitha Kumari ◽  
Etalo A. Secco
Keyword(s):  
Electrical Conductivity ◽  
High Temperature ◽  
Reaction Kinetics ◽  
Solid Phase ◽  
Thermal Analyses ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
Solid Liquid

Order–disorder transitions occurring in the Ag2SO4–K2SO4 system were investigated by reaction kinetics, thermal analyses, X-ray diffraction, and electrical conductivity techniques. Solid–liquid and solid–solid phase diagrams are reported.The conductivity data in the high temperature phase of the solid resemble superionic conductivity behavior. The higher conductivity of Ag2SO4 with K+ presence relative to pure Ag2SO4 and Ag2−xNaxSO4 compositions support a lattice expansion facilitating higher mobility of ions.The reaction kinetics, X-ray diffraction, and electroconductivity results suggest a relatively open periodic [Formula: see text] sublattice in the high-temperature phase of the sulfate-based systems studied in this series.

In Situ Observation of Growth Process of δ Phase of 0.15% C Carbon Steel during Solidification

2011 ◽  
Vol 299-300 ◽  
pp. 341-344
Author(s):  
Xu Dong Yue ◽  
Guang Can Jin ◽  
Shu Ying Chen ◽  
Guo Wei Chang
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Carbon Steel ◽  
Growth Process ◽  
High Temperature Phase ◽  
Liquid Interface ◽  
Temperature Phase ◽  
Solid Liquid Interface ◽  
Solid Liquid

In situ observation of growth process of high temperature phase in 0.15% C carbon steel during solidification concerned with using Confocal Scanning Laser Microscope (CSLM), the growth rate of -phase has been measured. The results indicate that high temperature -phase grows at cell crystal way when the cooling speed reaches 2°C/min in 0.15% C carbon steel. The -phase of round or oval cross-sectional shaped may grow stably. The growth rate of -phase is gradually getting slow along with increasing of curvature radius. The variation of growth speed tends to be similar with different solid-liquid interface shapes of -phase. The growth rate of concave solid-liquid interface is faster than that of convex solid-liquid interface for phase. The smaller radius of curvature of phase is, the faster the growth rate reaches.

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