scholarly journals An Experimental Study on the Thermal Stability of Mg2Si/Ni Interface under Thermal Cycling

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3117
Author(s):  
Sung-Jae Joo ◽  
Ji Eun Lee ◽  
Bong-Seo Kim ◽  
Bok-Ki Min
Keyword(s):  
Thermal Stability ◽  
Electrical Contact ◽  
Phase Interface ◽  
Temperature Cycling ◽  
Interfacial Region ◽  
Ternary Compounds ◽  
Thermal Expansion Coefficients ◽  
Long Time ◽  
Expansion Coefficients ◽  
Thermal Stability Of

Mg2Si is a promising eco-friendly thermoelectric material, and Ni is suited for electrical contact on it. In this study, Bi-doped Mg2Si ingots with Ni contacts were fabricated by co-sintering, and thermal stability was investigated by long-time (500 h, 500 cycles) temperature cycling from 25 °C to a peak temperature (Th = 400 and 450 °C) in N2. The as-sintered Ni/Mg2Si interfacial region is a multilayer consisting of Mg3Bi2, a series of MgxSiyNiz ternary compounds (ω, ν, ζ, and η-phases), and MgNi2. In the complex microstructure, the MgNi2 / η-phase interface was vulnerable to stress-induced voiding at Th = 450 °C, which arises from the mismatch of the thermal expansion coefficients. Interfacial voiding was avoided by adding 10 mol% Ag in Ni, which is probably due to the suppression of vacancy migration by the Ag-containing 2nd phase formation at the MgNi2/η-phase interface.

Effect of SiO2 Cap Layer on Thermal Stability of Nickel and Nickel-Cobalt Silicide

2006 ◽  
Vol 321-323 ◽  
pp. 1322-1325
Author(s):  
Kil Jin Han ◽  
Yu Jeong Cho ◽  
Soon Young Oh ◽  
Yong Jin Kim ◽  
Won Jae Lee ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Annealing Temperature ◽  
Nickel Silicide ◽  
Cobalt Silicide ◽  
Thermal Expansion Coefficients ◽  
Nickel Cobalt ◽  
Expansion Coefficients ◽  
The Difference ◽  
The Stability ◽  
Thermal Stability Of

We investigated the effect of SiOcap layer on the thermal stability of nickel and nickel-cobalt silicide by measuring its sheet resistance. The stability of nickel silicide was deteriorated as a function of annealing temperature, while that of nickel-cobalt silicide was not. In case of both silicides, the SiOcap layer improved the stability. Tensile stress from the difference of thermal expansion coefficients between SiO2 and nickel silicide may suppress the agglomeration of nickel silicide.

Temperature Cycling Induced Warpage of Packages with Embedded Copper Heatspreaders

2012 ◽  
Vol 2012 (DPC) ◽  
pp. 001579-001596
Author(s):  
Matthew Stahley ◽  
John Osenbach ◽  
Brenda Gogue ◽  
Byong Il Heo ◽  
Byung Cheol Lee ◽  
...  
Keyword(s):  
Integrated Circuit ◽  
Softening Temperature ◽  
Cycling Performance ◽  
Temperature Cycling ◽  
Electrical Performance ◽  
Micro Hardness ◽  
Thermal Expansion Coefficients ◽  
Plastic Ball ◽  
Qualification Testing ◽  
Expansion Coefficients

Temperature cycling is an important reliability qualification test given the differences in thermal expansion coefficients for the materials in integrated circuit packages. In this work, leadfree Plastic-Ball-Grid-Array (PBGA) packages with embedded C1100 copper heatspreaders were exposed to standard qualification testing including MSL3 Moisture Preconditioning with leadfree reflows at 245C followed by Temperature Cycling (TC) with ranges of −55/+125C (TC-B) and 0/+125C (TC-K) per JEDEC JESD47. Electrical performance and package warpage were characterized on as-received, post-preconditioning, and post-TC devices. After 200 cycles TC-B, gross electrical open failures were found on a large percentage of devices in some package lots. Physical failure analysis of the open failures revealed severe package warpage, as high as 20mils on a 31mm package. The severe warpage was accompanied by delamination and sheared wires. In contrast other package lots did not show failures nor severe warpage (<6mils) even after 1000 cycles of TC-B. The same package and BOM was qualified with 225C reflows for eutectic lead/tin solder with no warpage or failures after TC. Detailed commonality studies revealed that the copper heatspreader lot used was the only definitive difference between “good” and “warped” package lots. It was found that for “warped” lots exposure to the leadfree reflow at 245C caused a significant reduction in the micro-hardness of the copper heatspreader, while there was minimal change in micro-hardness after exposure to leadfree reflow in the “good” lots. The mechanism for this change is explained by the softening temperature of the C1100 copper heatspreader which is well within the range of leadfree reflows. Above this softening temperature, re-crystallization and grain growth occur, which result in susceptibility to permanent warpage induced by temperature cycling. Control of this warpage is critical to qualifying temperature cycling performance for heatspreader PBGA packages, and this can be achieved through micro-hardness screening of the heatspreaders.

scholarly journals The Structure and Thermal Properties of Solid Ternary Compounds Forming with Ca2+, Al3+ and Heptagluconate Ions

Molecules ◽  
2020 ◽  
Vol 25 (20) ◽  
pp. 4715
Author(s):  
Ákos Buckó ◽  
Zsolt Kása ◽  
Márton Szabados ◽  
Bence Kutus ◽  
Ottó Berkesi ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Metal Ion ◽  
Icp Oes ◽  
X Ray Diffraction ◽  
Metal Compounds ◽  
X Ray ◽  
Ternary Compounds ◽  
Centrally Symmetric ◽  
Ir And Raman ◽  
Thermal Stability Of

In the present work, the structure and thermal stability of Ca–Al mixed-metal compounds, relevant in the Bayer process as intermediates, have been investigated. X-ray diffraction (XRD) measurements revealed the amorphous morphology of the compounds, which was corroborated by SEM-EDX measurements. The results of ICP-OES and UV-Vis experiments suggested the formation of three possible ternary calcium aluminum heptagluconate (Ca-Al-Hpgl) compounds, with the formulae of CaAlHpgl(OH)40, Ca2AlHpgl2(OH)50 and Ca3Al2Hpgl3(OH)90. Additional IR and Raman experiments revealed the centrally symmetric arrangement of heptagluconate around the metal ion. The increased thermal stability was demonstrated by thermal analysis of the solids and confirmed our findings.

Investigation of Dependence between Thermal Stability for Nano-Dispersed Metals and Velocity of Flame Spreading and Time Storage

2014 ◽  
Vol 682 ◽  
pp. 357-362 ◽  
Author(s):  
Yulia A. Amelkovich ◽  
Olga B. Nazarenko ◽  
Alexander I. Sechin ◽  
Kristina O. Fraynova
Keyword(s):  
Thermal Stability ◽  
Storage Time ◽  
Electrical Explosion ◽  
Metal Powders ◽  
Flame Spreading ◽  
Long Time ◽  
Thermal Stability Of ◽  
Time Lead ◽  
Selection Of ◽  
Copper Nanopowders

Thermal stability of aluminum, iron and copper nanopowders, produced by electrical explosion of wire during heating in the air, was investigated in the work. Thermal analysis method was used for control of thermal stability for nanodispersed metals in heating in the air. It was shown, that after a long time of storage in air electrical explosion metal nanopowders have had extra active ones. Estimation of velocity of flame spreading in poured layer of the powders was carried out. Quality changes in investigated samples, happened for storage time, lead to increase of flame front length and its line velocity. The results of the researches could be used for diagnostics of fire danger of nanodispersed metals, also for selection of working regimes and provision of fire explosion safety for technologies which produce and apply of nanodispersed metal powders. Time-factor have not effected on criteria concerning the danger of the loads and have not changed its marking.

scholarly journals An insight into thermal stability of DNA in hydrated ionic liquids from multi-wavelengths UV Resonance Raman experiments

2021 ◽  
Author(s):  
Barbara Rossi ◽  
Mariagrazia Tortora ◽  
Sara Catalini ◽  
Jacopo Vigna ◽  
Ines Mancini ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Ionic Liquids ◽  
Biomedical Applications ◽  
Resonance Raman ◽  
Native Structure ◽  
Uv Resonance Raman ◽  
Alternative Solvents ◽  
Long Time ◽  
Thermal Stability Of ◽  
Insight Into

The utility of Ionic liquids (ILs) as alternative solvents for stabilizing and preserving for a long time the native structure of DNA may be envisaged for biotechnological and biomedical applications...

Study on Dependability and Repeatability of Measurement Method of Mean Linear Thermal Expansion Coefficients of Glasses

2013 ◽  
Vol 694-697 ◽  
pp. 1271-1275 ◽  
Author(s):  
Ying Liang Tian ◽  
Zhu Cui ◽  
Chun Mei Yuan ◽  
Xin Hui Liang ◽  
Shi Bing Sun ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Thermal Expansion ◽  
Thermodynamic Property ◽  
Measurement Method ◽  
Initial Temperature ◽  
Linear Thermal Expansion ◽  
Physical Property ◽  
Thermal Expansion Coefficients ◽  
Measurement Results ◽  
Expansion Coefficients

Coefficient of mean linear thermal expansion is an important physical property of glasses. It is the key thermodynamic property to evaluate the thermal stability and matching sealing of glasses. The measurement results of coefficient of mean linear thermal expansion obtained by different dilatometers showed that glass expands slowly with nonlinearity below 50 °C. It suggested that the initial temperature of measurement would be set above 50 °C, as behaves better repeatability and reliability of measurement than 20 °C as standard method set.

Study on the Morphology, Mechanical, Thermal Stability Properties of Poly(Lactic-Acid)/Poly(Ether-Block-Amide) Blends Prepared by Triple-Single Screw Extruder

2018 ◽  
Vol 783 ◽  
pp. 51-55
Author(s):  
Bin Xue ◽  
He Zhi He ◽  
Bi Da Liu ◽  
Feng Xue ◽  
Zhi Wen Zhu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Phase Interface ◽  
Poly Lactic Acid ◽  
Screw Extruder ◽  
Two Phase ◽  
Single Screw ◽  
Single Screw Extruder ◽  
The Impact ◽  
Thermal Stability Of

In this work, PLA /PEBA blends with the addition of different PEBA contents were prepared via self-made Triple-Single Screw Extruder, the phase morphology, mechanical properties thermal stability of PLA /PEBA blends with PEBA content were investigated. For the pure PLA, the tensile strength decreased, while the elongation at break and the impact strength increased significantly with addition of 15% PEBA. The which were improved nearly 23 and 5 times. The results illustrate that the soft component PEBA was beneficial to improve the tensile ductility and the toughness of PLA. SEM measurements indicate the PEBA and PLA intertwined with each other, two phases interface bond tightly, improving the compatibility of the blends when PEBA content is not more than 15 wt%, with further increasing PEBA, the two-phase interface appears and decreases the interfacial adhesion, resulting in the poor mechanical properties of blends.TG results reveal that thermal stability of PLA/PEBA blends was improved.

REPUBLIC HP 9-4-30

Alloy Digest ◽  
1972 ◽  
Vol 21 (7) ◽  
Keyword(s):  
Thermal Stability ◽  
Fracture Toughness ◽  
Heat Treating ◽  
Good Thermal Stability ◽  
Treated Condition ◽  
Heat Treated ◽  
Long Time ◽  
Heat Treated Condition ◽  
Thermal Stability Of ◽  
Minimum Yield

Abstract REPUBLIC HP 9-4-30 is a heat-treated alloy steel capable of developing minimum yield strengths up to 190,000 psi with superior toughness characteristics. It is designed for sheet, plate, and forging applications, and can be welded in the heat-treated condition. The good thermal stability of this alloy makes it attractive for applications requiring long-time exposures at temperatures up to 700 F. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as fracture toughness, creep, and fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SA-278. Producer or source: Republic Steel Corporation.

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