Microstructural stability of Ag sinter joining in thermal cycling

2012 ◽  
Vol 24 (4) ◽  
pp. 1332-1340 ◽  
Author(s):  
Soichi Sakamoto ◽  
Tohru Sugahara ◽  
Katsuaki Suganuma
Keyword(s):  
Thermal Cycling ◽  
Microstructural Stability ◽  
Sinter Joining

Microstructural Stability of Directionally Solidified Eutectic NiAl-Mo Under Static and Thermal Cycling Conditions

1996 ◽  
Vol 460 ◽  
Author(s):  
M. T. Kush ◽  
J. W. Holmes ◽  
R. Gibala
Keyword(s):  
Thermal Cycling ◽  
Microstructural Stability ◽  
Directionally Solidified ◽  
Argon Gas ◽  
Heating And Cooling ◽  
Annealing Conditions ◽  
Gas Atmosphere ◽  
Binary Eutectic ◽  
Temperature Heating ◽  
Large Shape

ABSTRACTThe quasi-binary eutectic NiAl-9% Mo with faceted molybdenum fibers was subjected to both thermal annealing conditions and to annealing under thermal cycling conditions to determine the microstructural stability of this alloy. The static temperature tests were run at 0.85TM - 0.97TM in an argon gas atmosphere. The thermal cycling tests were performed between temperatures of 700°C and 1200°C by induction heating disk-shaped specimens in an argon gas atmosphere using time-temperature heating and cooling profiles to approximate potential engine applications. To quantify microstructural changes, the fiber size and size distribution and number of fibers per unit area were measured as a function of time at temperature. The overall results demonstrate that the directionally solidified eutectic NiAl-9Mo subjected to thermal fatigue conditions exhibits cell boundary coarsening and large shape changes, whereas the microstructure under static stress-free annealing is stable.

Microstructural Stability Of a NiAI-Mo Eutectic Alloy

1998 ◽  
Vol 552 ◽  
Author(s):  
M. T. Kush ◽  
J. W. Holmes ◽  
R. Gibala
Keyword(s):  
Thermal Cycling ◽  
Thermal Stresses ◽  
Boundary Region ◽  
Microstructural Stability ◽  
Directionally Solidified ◽  
Columnar Microstructure ◽  
Heating And Cooling ◽  
Cellular Microstructure ◽  
Temperature Heating ◽  
Specimen Shape

ABSTRACTThe microstructural stability of a directionally-solidified NiA1–9 at.% Mo quasi-binary alloy was investigated under conditions of thermal cycling between the temperatures 973 K and 1473 K utilizing time-temperature heating and cooling profiles which approximate potential engine applications. Two different microstructures were examined: a cellular microstructure in which the faceted secondphase Mo rods in the NiAl matrix formed misaligned cell boundaries which separated aligned cells approximately 0.4 mm in width and 5–25 mm in length, and a nearly fault-free fully columnar microstructure well aligned along the [001] direction. Both microstructures resisted coarsening under thermal cycling, but plastic deformation induced by thermal stresses introduced significant specimen shape changes. Surprisingly, the cellular microstructure, for which the cell boundary region apparently acts as a deformation buffer, exhibited better resistance to thermal fatigue than the more fault-free and better aligned columnar microstructure.

Reliability of Ag Sinter-Joining Die Attach Under Harsh Thermal Cycling and Power Cycling Tests

2021 ◽  
Author(s):  
Zheng Zhang ◽  
Chuantong Chen ◽  
Aiji Suetake ◽  
Ming-Chun Hsieh ◽  
Katsuaki Suganuma
Keyword(s):  
Thermal Cycling ◽  
Die Attach ◽  
Power Cycling ◽  
Sinter Joining

Microstructural characterization of a rapidly solidified Al-Fe-V-Si alloy for elevated temperature applications

1988 ◽  
Vol 46 ◽  
pp. 550-551
Author(s):  
R. E. Franck ◽  
J. A. Hawk ◽  
G. J. Shiflet
Keyword(s):  
High Temperature ◽  
Elevated Temperature ◽  
Grain Growth ◽  
Volume Fraction ◽  
Microstructural Characterization ◽  
Second Phase ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Temperature Applications

Rapid solidification processing (RSP) is one method of producing high strength aluminum alloys for elevated temperature applications. Allied-Signal, Inc. has produced an Al-12.4 Fe-1.2 V-2.3 Si (composition in wt pct) alloy which possesses good microstructural stability up to 425°C. This alloy contains a high volume fraction (37 v/o) of fine nearly spherical, α-Al12(Fe, V)3Si dispersoids. The improved elevated temperature strength and stability of this alloy is due to the slower dispersoid coarsening rate of the silicide particles. Additionally, the high v/o of second phase particles should inhibit recrystallization and grain growth, and thus reduce any loss in strength due to long term, high temperature annealing.The focus of this research is to investigate microstructural changes induced by long term, high temperature static annealing heat-treatments. Annealing treatments for up to 1000 hours were carried out on this alloy at 500°C, 550°C and 600°C. Particle coarsening and/or recrystallization and grain growth would be accelerated in these temperature regimes.

High-Temperature Instability of A Cr2Nb-Nb(Cr) Microlaminate Composite

1996 ◽  
Vol 54 ◽  
pp. 374-375
Author(s):  
M. Larsen ◽  
R.G. Rowe ◽  
D.W. Skelly
Keyword(s):  
Heat Treatment ◽  
Solid Solution ◽  
High Temperature ◽  
Elevated Temperatures ◽  
Aircraft Engine ◽  
Lattice Parameter ◽  
Microstructural Stability ◽  
Elevated Temperature Strength ◽  
Cross Sectional ◽  
Bcc Structure

Microlaminate composites consisting of alternating layers of a high temperature intermetallic compound for elevated temperature strength and a ductile refractory metal for toughening may have uses in aircraft engine turbines. Microstructural stability at elevated temperatures is a crucial requirement for these composites. A microlaminate composite consisting of alternating layers of Cr2Nb and Nb(Cr) was produced by vapor phase deposition. The stability of the layers at elevated temperatures was investigated by cross-sectional TEM.The as-deposited composite consists of layers of a Nb(Cr) solid solution with a composition in atomic percent of 91% Nb and 9% Cr. It has a bcc structure with highly elongated grains. Alternating with this Nb(Cr) layer is the Cr2Nb layer. However, this layer has deposited as a fine grain Cr(Nb) solid solution with a metastable bcc structure and a lattice parameter about half way between that of pure Nb and pure Cr. The atomic composition of this layer is 60% Cr and 40% Nb. The interface between the layers in the as-deposited condition appears very flat (figure 1). After a two hour, 1200 °C heat treatment, the metastable Cr(Nb) layer transforms to the Cr2Nb phase with the C15 cubic structure. Grain coarsening occurs in the Nb(Cr) layer and the interface between the layers roughen. The roughening of the interface is a prelude to an instability of the interface at higher heat treatment temperatures with perturbations of the Cr2Nb grains penetrating into the Nb(Cr) layer.

PENGARUH THERMAL CYCLING TERHADAP PERUBAHAN DIMENSI DAN STABILITAS WARNA BAHAN BASIS GIGI TIRUAN NILON TERMOPLASTIK

2015 ◽  
Vol 18 (3) ◽  
pp. 280-284
Author(s):  
Dwi Tjahyaning Putranti ◽  
Oktia Kiki Triana
Keyword(s):  
Thermal Cycling

Nilon termoplastik sebagai bahan basis gigi tiruan mulai menjadi pilihan perawatan. Salah satu sifat fisis nilontermoplastik yang menjadi perhatian dalam penggunaannya sebagai bahan basis gigi tiruan adalah stabilitas dimensi danstabilitas warna. Penggunaan basis gigi tiruan di rongga mulut dalam waktu tertentu akan mengakibatkan berbagaiperubahan sifat bahan. Salah satu metode yang dapat digunakan untuk mengevaluasi sifat suatu bahan yaitu thermalcycling. Sampel dibuat sesuai ADA No. 12 untuk uji perubahan dimensi dan ISO No. 1567 untuk uji stabilitas warna.Thermal cycling 70 cycles dan 300 cycles dilakukan pada masing-masing sampel perlakuan. Hasil uji dianalisismenggunakan uji ANOVA untuk mengetahui pengaruh thermal cycling terhadap perubahan dimensi dan stabilitas warnayang menunjukkan hasil signifikan (p < 0,05) dibandingkan kelompok kontrol, serta uji LSD yang menunjukkan terdapatperbedaan pengaruh thermal cycling terhadap perubahan dimensi dan stabilitas warna bahan basis gigi tiruan nilontermoplastik. Thermal cycling 70 cycle dan 300 cycle pada bahan basis gigi tiruan nilon termoplastik dapat meningkatkannilai perubahan dimensi dan menurunkan nilai stabilitas warna bahan basis gigi tiruan nilon termoplastik. Kesimpulan,penggunaan gigi tiruan selama 1 minggu dibandingkan 1 bulan menyebabkan perubahan dimensi semakin besar danberkurangnya stabilitas warna pada basis gigi tiruan nilon termoplastik.

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