Modeling of Multi-Phase Solid State Reactions-Case of IMC Growth

2012 ◽  
Vol 323-325 ◽  
pp. 127-132
Author(s):  
M. Pawełkiewicz ◽  
Marek Danielewski ◽  
Jolanta Janczak-Rusch ◽  
Bartek Wierzba
Keyword(s):  
Solid State ◽  
Joint Strength ◽  
Void Formation ◽  
Solid State Reactions ◽  
Reactive Diffusion ◽  
Metallurgical Bond ◽  
Multi Phase ◽  
Reaction Processes ◽  
Different Time Scales ◽  
Simultaneous Growth

The formation of intermetallic compounds (IMC) at the solder-substrate interface is required to initiate the metallurgical bond. However, rapid growth of IMCs may degrade joint strength through i) the increased presence of a low toughness phase, ii) the consumption of the solderable surface (void formation) and iii) generation of primary and secondary stresses. Knowledge of mass transport and reaction processes during joint formation and service life are essential for solder system design. The mathematical description of inter-and reactive diffusion in open system presented here is based on Darken method (bi-velocity), involving the different molar volumes in the system and Wagner boundary conditions. It combines the interdiffusion, reactive diffusion and the effective flux constraints to couple processes occurring at different time scales. The rCADiff software serves as a tool to simulate simultaneous growth of the two Cu-Sn IMCs.

Combustion Synthesis of Sr-Substituted LaCo0.4Fe0.6O3 Powders

1992 ◽  
Vol 271 ◽  
Author(s):  
J. J. Kingsley ◽  
L. A. Chick ◽  
G. W. Coffey ◽  
D. E. McCready ◽  
L. R. Pederson
Keyword(s):  
Solid State ◽  
Metal Oxides ◽  
Mixed Oxides ◽  
Electronic Conductivity ◽  
Solid State Reactions ◽  
Bet Surface Area ◽  
Metal Nitrates ◽  
Subsequent Calcination ◽  
Multi Phase ◽  
Sorption Characteristics

ABSTRACTSr-substituted perovskite LaCo0.4Fe0.6O3 is known to have excellent mixed ionic and electronic conductivity and increased O2 sorption characteristics. These perovskites are usually prepared by lengthy solid-state reactions of the component oxides at temperatures near 1150°C, and often produce inhomogeneous, multi-phase powders. Presently, it has been prepared by the calcination of combustion-derived fine mixed oxides at 850°C in 6 hrs. Combustion reactions are carried out using precursor solutions containing the corresponding metal nitrates (oxidizers) and glycine (fuel) at 250°C. The metal oxides produced by this process and subsequent calcination were characterized by XRD, TEM and BET surface area analysis.

Atom Probe Tomography: Studying Reactions on Top of the Tip

2006 ◽  
Vol 46 ◽  
pp. 126-135 ◽  
Author(s):  
Guido Schmitz ◽  
Constantin Ene ◽  
Ch. Lang ◽  
Vitaliy Vovk
Keyword(s):  
Solid State ◽  
Atom Probe Tomography ◽  
Atom Probe ◽  
Modern Technology ◽  
Solid State Reactions ◽  
Reactive Diffusion ◽  
Atomic Transport ◽  
The Stability ◽  
Gmr Sensor ◽  
Detection And Localization

Down-scaling is a major principle of modern technology. As a consequence, the stability of many technical devices is controlled by solid state reactions that proceed on the range of a few nanometres only. On such a short length scale even basic aspects of reaction physics as fundamental as e.g. the Ficks laws of diffusion, need to be reconsidered. Only very few dedicated techniques are suitable to study atomic transport and reactions with sufficient accuracy. Among them, the atom probe tomography is exceptional, as it allows the detection and localization of individual atoms with an accuracy of a lattice constant. An almost complete reconstruction of the 3D atomic arrangement of different atomic species gets possible. This article provides an overview on recent atom probe studies of reactive diffusion. After an introduction into the principles of the analysis method, physical mechanisms of solid state reactions are discussed in view of recent experiments at metallic thin film interfaces. How does nucleation of an interfacial product take place? In which way do grain boundaries influence the reaction? As a technical example, the stability of Cu/NiFe GMR sensor layers is discussed.

Solid-State Reactions in Fe/Si Multilayer Nanofilms

2014 ◽  
Vol 215 ◽  
pp. 144-149 ◽  
Author(s):  
Sergey M. Zharkov ◽  
Roman R. Altunin ◽  
Evgeny T. Moiseenko ◽  
Galina M. Zeer ◽  
Sergey N. Varnakov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Electron Diffraction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Reaction Processes

Solid-state reaction processes in Fe/Si multilayer nanofilms have been studied in situ by the methods of transmission electron microscopy and electron diffraction in the process of heating from room temperature up to 900ºС at a heating rate of 8-10ºС/min. The solid-state reaction between the nanolayers of iron and silicon has been established to begin at 350-450ºС increasing with the thickness of the iron layer.

Experiments Proving the Mixed Control of the Reactive Diffusion System Zn/Fe3Si with Clamp Press

2006 ◽  
Vol 258-260 ◽  
pp. 59-62 ◽  
Author(s):  
Y.C. Chen ◽  
Hong Zhi Cui ◽  
J. Ding ◽  
Yun Bo Chen
Keyword(s):  
Diffusion Coefficient ◽  
Solid State ◽  
Quantitative Model ◽  
Diffusion System ◽  
Solid State Reactions ◽  
Reactive Diffusion ◽  
Layer Formation ◽  
Mixed Control ◽  
Periodic Layer ◽  
Uniaxial Compressive Stress

More than twenty years were needed for people to understand the formation mechanism of the periodic-layered structures not only because of the complications of pattern formation, but also due to the limits of traditional diffusion theories. Based on the general theory of interdiffusion growth proposed by Y.C. Chen et al. [1], the quantitative model of periodic layer formation during solid state reactions has been succeeded [2]. The experimental results shown in this paper proved one of the model’s predicts that the reactive diffusion system Zn/Fe3Si with clamp press annealed at 663K should be mixed controlled. Also, the important influence of the uniaxial compressive stress on the diffusion coefficient was emphasized and the reasons are discussed.

The effect of combined diffusion and kinetic transport barriers on multi-phase solid state reactions with a vapour reactant

1996 ◽  
Vol 31 (22) ◽  
pp. 5865-5871 ◽  
Author(s):  
W. B. Hillig ◽  
S. Adjerid ◽  
J. E. Flaherty ◽  
J. B. Hudson
Keyword(s):  
Solid State ◽  
Solid State Reactions ◽  
Transport Barriers ◽  
Multi Phase

Microstructural Variations in Melt-Spun Rapidly Solidified Ribbons

1985 ◽  
Vol 43 ◽  
pp. 54-55
Author(s):  
L. A. Bendersky ◽  
W. J. Boettinger
Keyword(s):  
Solid State ◽  
Processing Parameters ◽  
Heat Extraction ◽  
Solid State Reactions ◽  
Careful Examination ◽  
Ion Milling ◽  
Melt Spun ◽  
Wheel Side ◽  
Rapidly Solidified ◽  
Heat Extraction Rate

Rapid solidification produces a wide variety of sub-micron scale microstructure. Generally, the microstructure depends on the imposed melt undercooling and heat extraction rate. The microstructure can vary strongly not only due to processing parameters changes but also during the process itself, as a result of recalescence. Hence, careful examination of different locations in rapidly solidified products should be performed. Additionally, post-solidification solid-state reactions can alter the microstructure.The objective of the present work is to demonstrate the strong microstructural changes in different regions of melt-spun ribbon for three different alloys. The locations of the analyzed structures were near the wheel side (W) and near the center (C) of the ribbons. The TEM specimens were prepared by selective electropolishing or ion milling.

The wustite-spinel interface

1987 ◽  
Vol 45 ◽  
pp. 268-269
Author(s):  
S.R. Summerfelt ◽  
C.B. Carter
Keyword(s):  
Solid State ◽  
Solid State Reaction ◽  
Strain Energy ◽  
Matrix Material ◽  
Lattice Misfit ◽  
Solid State Reactions ◽  
Oxygen Sublattice ◽  
Large Particles ◽  
Small Lattice ◽  
Coherent Interfaces

The wustite-spinel interface can be viewed as a model interface because the wustite and spinel can share a common f.c.c. oxygen sublattice such that only the cations distribution changes on crossing the interface. In this study, the interface has been formed by a solid state reaction involving either external or internal oxidation. In systems with very small lattice misfit, very large particles (>lμm) with coherent interfaces have been observed. Previously, the wustite-spinel interface had been observed to facet on {111} planes for MgFe2C4 and along {100} planes for MgAl2C4 and MgCr2O4, the spinel then grows preferentially in the <001> direction. Reasons for these experimental observations have been discussed by Henriksen and Kingery by considering the strain energy. The point-defect chemistry of such solid state reactions has been examined by Schmalzried. Although MgO has been the principal matrix material examined, others such as NiO have also been studied.

TEM study of amorphization of Cu and Ti foils by cold-rolling

1990 ◽  
Vol 48 (4) ◽  
pp. 146-147
Author(s):  
W. A. Chiou ◽  
N. L. Jeon ◽  
Genbao Xu ◽  
M. Meshii
Keyword(s):  
Solid State ◽  
Cold Rolling ◽  
High Energy ◽  
Rapid Quenching ◽  
Vapor Condensation ◽  
Metallic Alloys ◽  
Solid State Reactions ◽  
High Energy Particle ◽  
Amorphous Metallic Alloys ◽  
Thin Foils

For many years amorphous metallic alloys have been prepared by rapid quenching techniques such as vapor condensation or melt quenching. Recently, solid-state reactions have shown to be an alternative for synthesizing amorphous metallic alloys. While solid-state amorphization by ball milling and high energy particle irradiation have been investigated extensively, the growth of amorphous phase by cold-rolling has been limited. This paper presents a morphological and structural study of amorphization of Cu and Ti foils by rolling.Samples of high purity Cu (99.999%) and Ti (99.99%) foils with a thickness of 0.025 mm were used as starting materials. These thin foils were cut to 5 cm (w) × 10 cm (1), and the surface was cleaned with acetone. A total of twenty alternatively stacked Cu and Ti foils were then rolled. Composite layers following each rolling pass were cleaned with acetone, cut into half and stacked together, and then rolled again.

The use of high-resolution FESEM to study solid-state phase transformations and reactions

1994 ◽  
Vol 52 ◽  
pp. 1028-1029
Author(s):  
P. G. Kotula ◽  
D. D. Erickson ◽  
C. B. Carter
Keyword(s):  
Solid State ◽  
High Resolution ◽  
Phase Transformations ◽  
High Efficiency ◽  
Sol Gel ◽  
Quantitative Information ◽  
Solid State Reactions ◽  
Critical Dimensions ◽  
Backscattered Electrons ◽  
Backscattered Electron

High-resolution field-emission-gun scanning electron microscopy (FESEM) has recently emerged as an extremely powerful method for characterizing the micro- or nanostructure of materials. The development of high efficiency backscattered-electron detectors has increased the resolution attainable with backscattered-electrons to almost that attainable with secondary-electrons. This increased resolution allows backscattered-electron imaging to be utilized to study materials once possible only by TEM. In addition to providing quantitative information, such as critical dimensions, SEM is more statistically representative. That is, the amount of material that can be sampled with SEM for a given measurement is many orders of magnitude greater than that with TEM.In the present work, a Hitachi S-900 FESEM (operating at 5kV) equipped with a high-resolution backscattered electron detector, has been used to study the α-Fe2O3 enhanced or seeded solid-state phase transformations of sol-gel alumina and solid-state reactions in the NiO/α-Al2O3 system. In both cases, a thin-film cross-section approach has been developed to facilitate the investigation. Specifically, the FESEM allows transformed- or reaction-layer thicknesses along interfaces that are millimeters in length to be measured with a resolution of better than 10nm.

Sign in / Sign up

Export Citation Format

Share Document