Mechanistic Model for Aging Influenced Steady State Flow Behavior of Sn3.8Ag0.7Cu Solder Alloys

2009 ◽  
Author(s):  
K. Mysore ◽  
S. Chavali ◽  
D. Chan ◽  
G. Subbarayan ◽  
I. Dutta ◽  
...  
Keyword(s):  
Steady State ◽  
Flow Behavior ◽  
Mechanistic Model ◽  
Secondary Creep ◽  
Aging Effects ◽  
Solder Alloys ◽  
Ambient Temperatures ◽  
Lap Shear ◽  
Random Microstructure ◽  
Mechanistic Basis

Sn3.8Ag0.7 Cu solder alloys age even at ambient temperatures. This significantly affects both microstructure and behavior of these alloys. In this work, aging influences on both are addressed. In particular, we discuss (a) honey comb type microstructure patterns in unaged samples and their subsequent evolution into a coarsened random microstructure at prolonged aging durations (b) aging effects on primary, secondary creep and on a range of applied loads and test temperatures through double lap shear experiments; the results show an increased tendency of aged solders to flow (c) a modified power law creep-plasticity model to predict aging effects on behavior. Possible mechanisms that result in the above behavior are also discussed; they motivate the mechanistic basis for the developed aging-informed behavior model, (d) procedures to compare alloys in terms of aging effects. Steady state creep strains, monotonic plastic strains and unified creep-plasticity theory are also discussed. Aging temperatures of −10 °C, 25°C, 75°C and 125°C, and aging times of 15, 30, 60 and 90 days (at each aging temperature) were selected as different levels of factors in a statistically designed experiment to study aging effects. Test specimens were selected with due pre-test considerations to joint-geometry, associated stress heterogeneity and joint-microstructures.

Observations of Changes in Rate Dependent Flow of SnAgCu Solder Alloys Due to Aging

2009 ◽  
Author(s):  
Sri Chaitra Chavali ◽  
Kaushik Mysore ◽  
Ganesh Subbarayan ◽  
Indranath Dutta
Keyword(s):  
Diffusion Processes ◽  
Flow Behavior ◽  
Intermetallic Particle ◽  
Particle Growth ◽  
Secondary Creep ◽  
Aging Effects ◽  
Solder Alloys ◽  
Creep Tests ◽  
Snagcu Solder ◽  
And Behavior

Aging affects both microstructure and behavior [1, 2]. Microstructural changes are driven by dislocation motion and diffusion processes. Together they affect the flow behavior in solder alloys. We address four aspects of solder microstructure and behavior as affected by aging (a) EDS studies on Ag dispersion in Sn matrix (b) a procedure for modeling intermetallic particle growth (c) a model for estimating effective viscosity of solder alloy (d) both primary and secondary creep models to predict aging effects on behavior. Solder samples were aged for different aging times (15, 30, 60, 90 days aging) and at different aging temperatures (25 C, 75 C, 125 C) prior to running creep tests. Another set of solder samples were similarly aged to characterize the microstructure. The creep data for the experiments are from a series of sixty four experiments performed using a micromechanical tester that is specially fitted with a sensitive capacitance gauge (with a resolution of 0.1 microns) to accurately measure viscoplastic responses of solder to applied loads.

Steady-State Flow Behavior of CO2 Foam

2004 ◽  
Author(s):  
J.S. Kim ◽  
Y. Dong ◽  
W.R. Rossen
Keyword(s):  
Steady State ◽  
Flow Behavior ◽  
Steady State Flow ◽  
State Flow ◽  
Co2 Foam

Artificial Intelligence Coreflooding Simulator for Special Core Data Analysis

2021 ◽  
pp. 1-29
Author(s):  
Eric Sonny Mathew ◽  
Moussa Tembely ◽  
Waleed AlAmeri ◽  
Emad W. Al-Shalabi ◽  
Abdul Ravoof Shaik
Keyword(s):  
Artificial Intelligence ◽  
Steady State ◽  
History Matching ◽  
Water Saturation ◽  
Flow Behavior ◽  
Model Performance ◽  
Analysis Data ◽  
Coefficient Of Determination ◽  
Water Drainage ◽  
Data Set

Two of the most critical properties for multiphase flow in a reservoir are relative permeability (Kr) and capillary pressure (Pc). To determine these parameters, careful interpretation of coreflooding and centrifuge experiments is necessary. In this work, a machine learning (ML) technique was incorporated to assist in the determination of these parameters quickly and synchronously for steady-state drainage coreflooding experiments. A state-of-the-art framework was developed in which a large database of Kr and Pc curves was generated based on existing mathematical models. This database was used to perform thousands of coreflood simulation runs representing oil-water drainage steady-state experiments. The results obtained from the corefloods including pressure drop and water saturation profile, along with other conventional core analysis data, were fed as features into the ML model. The entire data set was split into 70% for training, 15% for validation, and the remaining 15% for the blind testing of the model. The 70% of the data set for training teaches the model to capture fluid flow behavior inside the core, and then 15% of the data set was used to validate the trained model and to optimize the hyperparameters of the ML algorithm. The remaining 15% of the data set was used for testing the model and assessing the model performance scores. In addition, K-fold split technique was used to split the 15% testing data set to provide an unbiased estimate of the final model performance. The trained/tested model was thereby used to estimate Kr and Pc curves based on available experimental results. The values of the coefficient of determination (R2) were used to assess the accuracy and efficiency of the developed model. The respective crossplots indicate that the model is capable of making accurate predictions with an error percentage of less than 2% on history matching experimental data. This implies that the artificial-intelligence- (AI-) based model is capable of determining Kr and Pc curves. The present work could be an alternative approach to existing methods for interpreting Kr and Pc curves. In addition, the ML model can be adapted to produce results that include multiple options for Kr and Pc curves from which the best solution can be determined using engineering judgment. This is unlike solutions from some of the existing commercial codes, which usually provide only a single solution. The model currently focuses on the prediction of Kr and Pc curves for drainage steady-state experiments; however, the work can be extended to capture the imbibition cycle as well.

Prediction of High Viscosity Liquid/Gas Two-Phase Slug Length in Horizontal and Slightly Inclined Pipelines

2021 ◽  
Author(s):  
Omar Shaaban ◽  
Eissa Al-Safran
Keyword(s):  
Numerical Optimization ◽  
Flow Behavior ◽  
Mechanistic Model ◽  
High Viscosity ◽  
Oil Well ◽  
Liquid Slug ◽  
Two Phase ◽  
Proposed Model ◽  
Wide Range ◽  
Flow Closure

Abstract The production and transportation of high viscosity liquid/gas two-phase along petroleum production system is a challenging operation due to the lack of understanding the flow behavior and characteristics. In particular, accurate prediction of two-phase slug length in pipes is crucial to efficiently operate and safely design oil well and separation facilities. The objective of this study is to develop a mechanistic model to predict high viscosity liquid slug length in pipelines and to optimize the proper set of closure relationships required to ensure high accuracy prediction. A large high viscosity liquid slug length database is collected and presented in this study, against which the proposed model is validated and compared with other models. A mechanistic slug length model is derived based on the first principles of mass and momentum balances over a two-phase slug unit, which requires a set of closure relationships of other slug characteristics. To select the proper set of closure relationships, a numerical optimization is carried out using a large slug length dataset to minimize the prediction error. Thousands of combinations of various slug flow closure relationships were evaluated to identify the most appropriate relationships for the proposed slug length model under high viscosity slug length condition. Results show that the proposed slug length mechanistic model is applicable for a wide range of liquid viscosities and is sensitive to the selected closure relationships. Results revealed that the optimum closure relationships combination is Archibong-Eso et al. (2018) for slug frequency, Malnes (1983) for slug liquid holdup, Jeyachandra et al. (2012) for drift velocity, and Nicklin et al. (1962) for the distribution coefficient. Using the above set of closure relationships, model validation yields 37.8% absolute average percent error, outperforming all existing slug length models.

High-Temperature Mechanical Behavior of B2 Type IrAl Doped With Ni

1996 ◽  
Vol 460 ◽  
Author(s):  
A. Chiba ◽  
T. Ono ◽  
X. G. Li ◽  
S. Takahashi
Keyword(s):  
Steady State ◽  
Mechanical Behavior ◽  
Constant Velocity ◽  
Single Phase ◽  
Elevated Temperatures ◽  
Constant Load ◽  
Secondary Creep ◽  
Compression Tests ◽  
Order Of Magnitude ◽  
Multi Phase

ABSTRACTConstant-velocity and constant-load compression tests have been conducted to examine the mechanical behavior of polycrystalline IrAl and Ir1-xNixAl at ambient and elevated temperatures. Although IrAl exhibits brittle fracture before or immediately after yielding below 1073K, steady-state deformation takes place at temperatures higher than 1273K. Ductility of Ir1-xNixAl is improved with increasing x. On the contrary, strength decreases with increasing x. IrAl exhibits the 0.2% flow stress of 1200MPa at 1073K and 350MPa at 1473K, about an order of magnitude higher than NiAl. Secondary creep of IrAl and Ir0.2Ni0.8Al(i.e., modified NiAl) exhibits class II and class I behavior respectively. Creep strength of binary IrAl and modified NiAl with Ir is about a magnitude of 4 higher than that of single-phase and multi-phase NiAl at a given applied stress.

Steady‐State Melt Flow Behavior of Polyethylene Blends

1965 ◽  
Vol 9 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Nobuyuki Nakajima ◽  
Patrick S. L. Wong
Keyword(s):  
Steady State ◽  
Flow Behavior ◽  
Melt Flow ◽  
Polyethylene Blends

Modeling Two-Phase Flow Inside an Electrical Submersible Pump Stage

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Lissett Barrios ◽  
Mauricio Gargaglione Prado
Keyword(s):  
Drag Coefficient ◽  
Bubble Size ◽  
Flow Behavior ◽  
Mechanistic Model ◽  
Force Balance ◽  
Submersible Pump ◽  
Bubble Behavior ◽  
Two Phase ◽  
Operational Conditions ◽  
Electrical Submersible Pump

Dynamic multiphase flow behavior inside a mixed flow electrical submersible pump (ESP) has been studied experimentally and theoretically for the first time. The overall objectives of this study are to determine the flow patterns and bubble behavior inside the ESP and to predict the operational conditions that cause surging. The theoretical study includes a mechanistic model for the prediction of the flow behavior inside the pump. The model comprises a one-dimensional force balance to predict occurrence of the stagnant bubbles at the channel intake. This model depends on two important variables, namely the stagnant bubble size and the bubble drag coefficient. The bubble size has been measured and a physically based correlation is presented. A new correlation for the drag coefficient is proposed as a function of rotational speed and Reynolds number. The model enables the prediction of the operational envelope of the ESP, namely the transition to surging.

Effect of Sb additions on the creep behaviour of low temperature lead-free Sn–8Zn–3Bi solder alloy

2020 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guang Ren ◽  
Maurice Collins
Keyword(s):  
Low Temperature ◽  
Solder Alloy ◽  
Creep Behaviour ◽  
Lead Free ◽  
Coefficient Of Determination ◽  
Secondary Creep ◽  
Lead Free Solder ◽  
Solder Alloys ◽  
Content Type ◽  
Free Solder

Purpose This paper aims to investigate the creep behaviour of the recently developed Sn–8Zn–3Bi–xSb (x = 0, 0.5, 1.0 and 1.5) low temperature lead-free solder alloys. Design/methodology/approach An in-house compressive test rig was developed to perform creep tests under stresses of 20–40 MPa and temperature range 25°C–75 °C. Dorn power law and Garofalo hyperbolic sine law were used to model the secondary creep rate. Findings High coefficient of determination R2 of 0.99 is achieved for both the models. It was found that the activation energy of Sn–8Zn–3Bi solder alloy can be significantly increased with addition of Sb, by 60% to 90 kJ/mol approximately, whereas the secondary creep exponent falls in the range 3–7. Improved creep resistance is attributed to solid solution strengthening introduced by micro-alloying. Creep mechanisms that govern the deformation of these newly developed lead-free solder alloys have also been proposed. Originality/value The findings are expected to fill the gap of knowledge on creep behaviour of these newly developed solder alloys, which are possible alternatives as lead-free interconnecting material in low temperature electronic assembly.

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