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- The 8th International Conference on Physical and Numerical Simulation of Materials Processing (10)
- Materials Science and Engineering Faculty Research & Creative Works (3)
- Mechanical and Aerospace Engineering Faculty Research & Creative Works (2)
- Bachelors Theses and Reports, 1928 - 1970 (1)
- Conference Papers (1)
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Articles 1 - 20 of 20
Full-Text Articles in Engineering
Engineering Heterogeneous Nucleation During Solidification Of Multiphase Cast Alloys: An Overview, Simon (Semen) N. Lekakh, Jingjing Qing
Engineering Heterogeneous Nucleation During Solidification Of Multiphase Cast Alloys: An Overview, Simon (Semen) N. Lekakh, Jingjing Qing
Materials Science and Engineering Faculty Research & Creative Works
The theory of heterogeneous nucleation was initially developed as a part of condensed matter physics, and later it was used as an important engineering tool to design metallurgical processes. This success has led to wide applications of the theory in metallurgical practice. For example, engineering heterogeneous nucleation in ductile iron has been used to reduce shrinkage defects, suppress cementite formation, and modify the size and shape of microstructural constituencies. This demonstrates how theoretical knowledge could benefit industry practice. This overview aims to summarize the authors' published studies in co-authorship with colleagues and students, which covers different aspects of engineering heterogeneous …
In Situ Sem Solidification Study Of Ga And Egain: A Characterization Technique For Monitoring The Microstructural Evolution Of Liquid Metals, Jeremy Geovann Del Aguila
In Situ Sem Solidification Study Of Ga And Egain: A Characterization Technique For Monitoring The Microstructural Evolution Of Liquid Metals, Jeremy Geovann Del Aguila
Materials Engineering
Scanning electron microscopy (SEM) video recording is used to characterize the solidification of small volumes of 99.999% pure gallium (Ga) and eutectic gallium-indium (eGaIn) under a high vacuum environment. Specimen are superheated to 55℃ using a hot plate, cast into spherical droplets, and cooled in situ by means of a Peltier cooling stage. Special attention is given to the preparation of the specimen prior to viewing because of gallium and its alloys’ nature to form an oxide layer when melted and air cooled. The oxide acts as a skin that inhibits the observation of microstructural features during solidification. Heated samples …
Preliminary Investigations Into Selective Laser Melting, David Takeo Otsu
Preliminary Investigations Into Selective Laser Melting, David Takeo Otsu
Master's Theses
Selective laser melting is a promising metallic additive manufacturing process with many potential applications in a variety of industries. Through a gracious donation made by Lawrence Livermore National Laboratory, California Polytechnic State University received and installed an SLM 125 HL selective laser melting machine in February 2017. As part of the initial setup effort, a preliminary machine verification study was conducted to evaluate the general print quality of the machine with default parameter settings. Coincidentally, the as-printed microstructure of SLM components was evaluated through nil strength fracture surface examination, an alternative to conventional polish-and-etch metallography. A diverse set of components …
Control Of Columnar To Equiaxed Transition In Solidification Macrostructure Of Austenitic Stainless Steel Castings, Semen Naumovich Lekakh, Ronald J. O'Malley, Mark C. Emmendorfer, Brenton Hrebec
Control Of Columnar To Equiaxed Transition In Solidification Macrostructure Of Austenitic Stainless Steel Castings, Semen Naumovich Lekakh, Ronald J. O'Malley, Mark C. Emmendorfer, Brenton Hrebec
Materials Science and Engineering Faculty Research & Creative Works
Solidification macrostructure is of great importance for the properties and the quality of castings made from austenitic grade stainless steels (ASS) because there are limited options to change as-cast macrostructure in the solid condition. A typical cast macrostructure of ASS has a fine surface chilled zone followed by an elongated dendrite zone, columnar to equiaxed transition (CET) zone, and centrally located equiaxed crystals. Several castings from ASS were produced to determine the effects of casting geometry, chilling, and grain refinement on CET. The transient thermal field in solidified heavy castings was simulated and used to determine an isotherm velocity (V) …
The Influence Of Welding Parameters On Initial Instability Dynamics During Solidification, Fengyi Yu, Yanhong Wei, Xiaohong Zhan
The Influence Of Welding Parameters On Initial Instability Dynamics During Solidification, Fengyi Yu, Yanhong Wei, Xiaohong Zhan
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Thermoelectric Magnetohydrodynamic Effects In Solidification Processes, Andrew Kao, Koulis Pericleous, Peter Lee, Biao Cai, Jianrong Gao
Thermoelectric Magnetohydrodynamic Effects In Solidification Processes, Andrew Kao, Koulis Pericleous, Peter Lee, Biao Cai, Jianrong Gao
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Physical Simulation Of The Effect Of Mechanical Vibration On Feeding Flow During Solidification Of Paste Alloy, Chen Wei, Wu Shi Ping, Wang Rujia
Physical Simulation Of The Effect Of Mechanical Vibration On Feeding Flow During Solidification Of Paste Alloy, Chen Wei, Wu Shi Ping, Wang Rujia
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Numerical Simulation Of The Through Process Of Aerospace Titanium Alloy Casting Filling, Solidification, And Hot Isostatic Pressing, Jian-Xin Zhou, Zhao Guo, Ya-Jun Yin, Chang-Chang Liu
Numerical Simulation Of The Through Process Of Aerospace Titanium Alloy Casting Filling, Solidification, And Hot Isostatic Pressing, Jian-Xin Zhou, Zhao Guo, Ya-Jun Yin, Chang-Chang Liu
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Thermal Simulation Of Continuous Casting Solidification Process For A 2205 Duplex Stainless Steel, Xiangru Chen, Qijie Zhai
Thermal Simulation Of Continuous Casting Solidification Process For A 2205 Duplex Stainless Steel, Xiangru Chen, Qijie Zhai
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Mould Corner Radius-Related Flow And Thermal States In Bloom Continuous Casting With A Swirling Flow Nozzle, Shaoxiang Li, Peng Lan, Haiyan Tang, Chenwei Du, Yuan Ji, Jiaquan Zhang
Mould Corner Radius-Related Flow And Thermal States In Bloom Continuous Casting With A Swirling Flow Nozzle, Shaoxiang Li, Peng Lan, Haiyan Tang, Chenwei Du, Yuan Ji, Jiaquan Zhang
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Particle Pushing: Reexamine The Thermodynamic Criterion, Qingyou Han
Particle Pushing: Reexamine The Thermodynamic Criterion, Qingyou Han
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Liquid/Substrate Interface For The Heterogeneous Nucleation In Grain Refinement Of Al Alloys, Yanfeng Han, Jun Xu, Hanlong Zhang, Yongbing Dai, Jiao Zhang, Jun Wang, Baode Sun
Liquid/Substrate Interface For The Heterogeneous Nucleation In Grain Refinement Of Al Alloys, Yanfeng Han, Jun Xu, Hanlong Zhang, Yongbing Dai, Jiao Zhang, Jun Wang, Baode Sun
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Study On Growth Model Of Cellular Automata Method In Solidification Simulation, Zhao Guo, Jian-Xin Zhou, Ya-Jun Yin, Chang-Chang Liu
Study On Growth Model Of Cellular Automata Method In Solidification Simulation, Zhao Guo, Jian-Xin Zhou, Ya-Jun Yin, Chang-Chang Liu
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Thermal Simulation Technology For Solidification Process Of Metals, Qijie Zhai, Honggang Zhong, Renxing Li, Hongxing Zheng
Thermal Simulation Technology For Solidification Process Of Metals, Qijie Zhai, Honggang Zhong, Renxing Li, Hongxing Zheng
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Probabilistic Simulation Of Solidification Microstructure Evolution During Laser-Based Metal Deposition, Jingwei Zhang, Frank W. Liou, William Seufzer, Joseph William Newkirk, Zhiqiang Fan, Heng Liu, Todd E. Sparks
Probabilistic Simulation Of Solidification Microstructure Evolution During Laser-Based Metal Deposition, Jingwei Zhang, Frank W. Liou, William Seufzer, Joseph William Newkirk, Zhiqiang Fan, Heng Liu, Todd E. Sparks
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A predictive model, based on a Cellular Automaton (CA) - Finite Element (FE) method, has been developed to simulate microstructure evolution during metal solidification for a laser based additive manufacturing process. The macroscopic FE calculation was designed to update the temperature field and simulate a high cooling rate. In the microscopic CA model, heterogeneous nucleation sites, preferential growth orientation and dendritic grain growth kinetics were simulated. The CA model was able to show the entrapment of neighboring cells and the relationship between undercooling and the grain growth rate. The model predicted the dendritic grain size, structure, and morphological evolution during …
Review Of The Maxus 8 Sounding Rocket Experiment To Investigate Solidification In A Ti-Al-Nb Alloy, Robin Mooney, David Browne, Olga Budenkova, Yves R. Fautrelle, Ludo Froyen, Andrey Kartavykh, Stephan Rex, Burkhard Schmitz, Daniella Voss, Shaun Mcfadden
Review Of The Maxus 8 Sounding Rocket Experiment To Investigate Solidification In A Ti-Al-Nb Alloy, Robin Mooney, David Browne, Olga Budenkova, Yves R. Fautrelle, Ludo Froyen, Andrey Kartavykh, Stephan Rex, Burkhard Schmitz, Daniella Voss, Shaun Mcfadden
Conference Papers
A review of the MAXUS 8 sounding rocket microgravity experiment to investigate solidification structures in a Ti-Al-Nb intermetallic alloy is presented. The experiment was part of the Intermetallic Materials Processing in Relation to Earth and Space Solidification (IMPRESS) EU FP6 project. Key objectives were to investigate columnar and equiaxed solidification, and to achieve Columnar-to-Equiaxed Transition (CET) in the alloy. A microgravity experiment was designed to achieve this using a controlled power-down method. Two alloys were tested: one inoculated with a grain refiner and the other without grain refinement. Unrefined samples displayed axial and radial columnar growth. Boride inoculated samples displayed …
Numerical Simulation Of The Evolution Of Solidification Microstructure In Laser Deposition, Zhiqiang Fan, Todd E. Sparks, Frank W. Liou, Anand Jambunathan, Yaxin Bao, Jianzhong Ruan, Joseph William Newkirk
Numerical Simulation Of The Evolution Of Solidification Microstructure In Laser Deposition, Zhiqiang Fan, Todd E. Sparks, Frank W. Liou, Anand Jambunathan, Yaxin Bao, Jianzhong Ruan, Joseph William Newkirk
Mechanical and Aerospace Engineering Faculty Research & Creative Works
A predictive model is developed to simulate the evolution of the solidification microstructure during the laser deposition process. The microstructure model is coupled with a comprehensive macroscopic thermodynamic model. This model simulates dendritic grain structures and morphological evolution in solidification. Based on the cellular automata approach, this microstructure model takes into account the heterogeneous nucleation both within the melt pool and at the substrate/melt interface, the growth kinetics, and preferential growth directions of dendrites. Both diffusion and convection effects are included. This model enables prediction and visualization of grain structures during and after the deposition process. This model is applied …
An Experimental Study Of Molten Microdroplet Surface Deposition And Solidification: Transient Behavior And Wetting Angle Dynamics, Daniel Attinger, Z. Zhao, D. Poulikakos
An Experimental Study Of Molten Microdroplet Surface Deposition And Solidification: Transient Behavior And Wetting Angle Dynamics, Daniel Attinger, Z. Zhao, D. Poulikakos
Daniel Attinger
The basic problem of the impact and solidification of molten droplets on a substrate is of central importance to a host of processes. An important and novel such process in the area of micromanufacturing is solder jetting where microscopic solder droplets are dispensed for the attachment of microelectronic components. Despite the recent appearance of a few numerical studies focusing on the complex transient aspects of this process, no analogous experimental results have been reported to date to the best of our knowledge. Such a study is reported in this paper. Eutectic solder (63Sn37Pb) was melted to a preset superheat and …
The Effect Of Casting Shape And Size On Solidification Time: A New Approach, Murat Tiryakioǧlu, Ergin Tiryakioǧlu, Donald R. Askeland
The Effect Of Casting Shape And Size On Solidification Time: A New Approach, Murat Tiryakioǧlu, Ergin Tiryakioǧlu, Donald R. Askeland
Materials Science and Engineering Faculty Research & Creative Works
The limitations of Chvorinov's Rule for predicting the solidification time of a casting are discussed and previous studies intended to modify Chvorinov's Rule in order to express the effect of the size and shape of castings on solidification time are reviewed. A new model that introduces a shape factor is presented that predicts the solidification times of castings as well as or better than Chvorinov's Rule, particularly for more complex shapes. The validity of the new model is compared with the conventional Chvorinov's Rule by a statistical analysis of twelve sets of data obtained from the literature.
Growth Of A Preferentially Oriented Aluminum Single Crystal, John George Bjeletich
Growth Of A Preferentially Oriented Aluminum Single Crystal, John George Bjeletich
Bachelors Theses and Reports, 1928 - 1970
When studying some anisotropic property of a specific metal, such as the critical shear stress of aluminum, it is desirable that the test specimen be a single crystal with the crystal axes preferentially oriented. Therefore, it is necessary to obtain a single crystal by one of the methods mentioned and by use of x-rays to determine the orientation. Once the single crystal is obtained and the orientation known, it is possible to grow a preferentially oriented aluminum single crystal by a method generally known as "seeding". The purpose of this thesis problem was to grow a crystal by utilizing the …