Open Access. Powered by Scholars. Published by Universities.®
Materials Science and Engineering Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Metallurgy (89)
- Other Materials Science and Engineering (77)
- Polymer and Organic Materials (67)
- Structural Materials (29)
- Semiconductor and Optical Materials (24)
-
- Curriculum and Social Inquiry (21)
- Education (21)
- Biology and Biomimetic Materials (17)
- Aerospace Engineering (10)
- Engineering Science and Materials (10)
- Biomedical Engineering and Bioengineering (9)
- Ceramic Materials (9)
- Chemical Engineering (9)
- Mechanical Engineering (9)
- Structures and Materials (8)
- Electrical and Computer Engineering (6)
- Physical Sciences and Mathematics (6)
- Biomaterials (5)
- Chemistry (5)
- Life Sciences (5)
- Manufacturing (5)
- Mechanics of Materials (5)
- Nanoscience and Nanotechnology (5)
- Polymer Science (5)
- Computer-Aided Engineering and Design (4)
- Polymer Chemistry (4)
- Biochemistry (3)
- Biochemistry, Biophysics, and Structural Biology (3)
- Keyword
-
- Materials Engineering (63)
- Materials engineering (28)
- Learning Suite (20)
- Aluminum (13)
- Forging (13)
-
- Corrosion (12)
- Composite (11)
- Cheating (9)
- Ti-6Al-4V (9)
- Polymer (8)
- Heat Treatment (7)
- Quantum Dots (7)
- Titanium (7)
- Cellulose (6)
- Composites (6)
- PDMS (6)
- Tensile Test (6)
- Academic dishonesty (5)
- Aerospace (5)
- Bamboo (5)
- Biopolymer (5)
- Ethics (5)
- Fluorescence (5)
- Guide Wires (5)
- Metallography (5)
- SEM (5)
- Solar (5)
- Additive Manufacturing (4)
- Arabinan (4)
- Biomimicry (4)
- Publication Year
- Publication Type
- File Type
Articles 361 - 390 of 394
Full-Text Articles in Materials Science and Engineering
Effect Of Foreign Object Damage On The Fatigue Strength Of An Xd™ Γ-Tial Alloy, Trevor S. Harding, J. Wayne Jones
Effect Of Foreign Object Damage On The Fatigue Strength Of An Xd™ Γ-Tial Alloy, Trevor S. Harding, J. Wayne Jones
Materials Engineering
High cycle fatigue has become the leading cause of failure in gas turbine engine blades in recent years [1]. The majority of these failures were associated with surface damage such as foreign object damage (FOD). Therefore, the ability of a material to resist impact damage and the subsequent fatigue propagation of any cracks that may result has become a crucial design consideration. Substantial research has been conducted on the effects of simulated FOD in conventional turbine blade materials where the formation of cracks at the impact site was not a common occurrence [2, 3 and 4]. However, impacts of more …
The Effect Of Impact Damage On The Room-Temperature Fatigue Behavior Of Γ-Tial, Trevor S. Harding, J. Wayne Jones
The Effect Of Impact Damage On The Room-Temperature Fatigue Behavior Of Γ-Tial, Trevor S. Harding, J. Wayne Jones
Materials Engineering
The relationship between impact damage and the fatigue behavior of γ-TiAl has been examined. Axial fatigue specimens fabricated from cast Ti-47.9Al-2.0Cr-1.9Nb (to be referred to as 48-2-2) and Ti-47.3Al-2.2Nb-0.5Mn-0.4W-0.4Mo-0.23Si (to be referred to as WMS) alloys were damaged by impact under controlled conditions with a 60 deg wedge-shaped indenter to simulate assembly-related damage in low-pressure turbine blades. The level of damage produced was quantified and found to correlate well with the peak load of the impact event. The WMS alloy exhibited a greater resistance to impact damage due to its higher yield strength and lamellar microstructure. A measure of the …
Implementing An Engineering Teaching Development Program For Graduate Student Instructors, Sara Soderstrom, Christian Lorenz, Michael Keinath, Trevor S. Harding
Implementing An Engineering Teaching Development Program For Graduate Student Instructors, Sara Soderstrom, Christian Lorenz, Michael Keinath, Trevor S. Harding
Materials Engineering
The Engineering Teaching Development Project (ETDP), a pilot program started by the student chapter of ASEE at the University of Michigan, is a multi-component program designed to improve the long-term teaching skills of graduate student instructors (GSIs) in the College of Engineering. The first component of the ETDP is college-wide pedagogical workshop series. These workshops are conducted by nationally recognized engineering educators invited by the ASEE student chapter. The topics of these workshops include cooperative learning, diversity in the classroom, and classroom assessment techniques. These workshops offer a means of continual improvement for all of the educators in the university, …
Photoresist Coating Process Control With Solvent Vapor Sensor, Richard N. Savage, Herbert Litvak, Emir Gurer
Photoresist Coating Process Control With Solvent Vapor Sensor, Richard N. Savage, Herbert Litvak, Emir Gurer
Materials Engineering
An apparatus for spin coating surfaces with liquid polymer comprises a spin coating chamber having a rotatable chuck for supporting an object to be coated. A distributor introduces gases into the chamber. A solvent vapor and carrier gas supply provides a carrier gas having a controlled level of solvent vapor therein within the range of from 0 to saturation concentrations of solvent vapor. A solvent vapor sensor is positioned with respect to the coating chamber to produce signals which correspond to the concentration of solvent vapor in the coating chamber. A control means is connected to the solvent vapor concentration …
Behavior Of Gamma Tial Subjected To Impact Damage And Elevated Temperature Fatigue, Trevor S. Harding, J. Wayne Jones
Behavior Of Gamma Tial Subjected To Impact Damage And Elevated Temperature Fatigue, Trevor S. Harding, J. Wayne Jones
Materials Engineering
Gamma titanium aluminide has received significant attention in recent years as a candidate material for use in aerospace and industrial gas turbine engine applications. In particular, these materials offer significant weight reductions (densities are less than half that of nickel-based superalloys), high specific strength retention at elevated temperature and high specific stiffness which is particularly important in vibrating components such as blades. This combination of weight savings and good mechanical properties has led to the possibility that γ-TiAl may be a suitable replacement for nickel-based alloys, such as Inconel 718, in low pressure turbine blades without significant redesign of the …
Theoretical And Experimental Investigation On The Low Temperature Properties Of The Nbcr2 Laves Phase, Dan J. Thoma, Chu Fuming, Katherine C. Chen, Paul G. Kotula, Terence E. Mitchell, John M. Wills, Alim Ormeci, Shao Ping Chen, Robert C. Albers
Theoretical And Experimental Investigation On The Low Temperature Properties Of The Nbcr2 Laves Phase, Dan J. Thoma, Chu Fuming, Katherine C. Chen, Paul G. Kotula, Terence E. Mitchell, John M. Wills, Alim Ormeci, Shao Ping Chen, Robert C. Albers
Materials Engineering
This is the final report of a three-year, Laboratory Directed Research and Development (LDRD) project at Los Alamos National Laboratory (LANL). The goal of the project was to develop methodologies in which to define and improve the properties of NbCr2 so that the high temperature structural applications of alloys based upon this would not be limited by the low-temperature brittle behavior of the intermetallic. We accomplished this task by (1) understanding the defect structure and deformation mechanisms in Laves phases, (2) electronic and geometric contributions to phase stability and alloying behavior, and (3) novel processing of dual phase (Laves/bcc) …
Training Graduate Student Instructors Effectively: The University Of Michigan Model, Trevor S. Harding
Training Graduate Student Instructors Effectively: The University Of Michigan Model, Trevor S. Harding
Materials Engineering
No abstract provided.
Room Temperature Fatique Response Of Γ-Tial To Impact Damage, Trevor S. Harding, J. Wayne Jones, P. S. Steif, T. M. Pollock
Room Temperature Fatique Response Of Γ-Tial To Impact Damage, Trevor S. Harding, J. Wayne Jones, P. S. Steif, T. M. Pollock
Materials Engineering
Gamma based titanium aluminides have received considerable attention recently as candidate materials in gas turbine applications, particularly low pressure turbine blades (1–3). Their low density and high specific stiffness, result in potentially significant weight savings in structures such as gas turbine engines if substituted for current materials. Two γ-TiAl microstructures are predominately identified in the literature: a lamellar microstructure consisting of alternating plates of γ and α2, and a duplex microstructure consisting of equiaxed γ grains and lamellar colonies (3,4). Lamellar alloys generally exhibit better fracture toughness and fatigue crack growth resistance (5–7). Duplex alloys, on the other …
Microstructures And Mechanical Properties Of Two-Phase Alloys Based On Nbcr2, Katherine C. Chen, Paul G . Kotula, Carl M. Cady, Michael E. Mauro, Dan J. Thoma
Microstructures And Mechanical Properties Of Two-Phase Alloys Based On Nbcr2, Katherine C. Chen, Paul G . Kotula, Carl M. Cady, Michael E. Mauro, Dan J. Thoma
Materials Engineering
A two-phase, NbCrTi alloy (bcc + C15 Laves phase) has been developed using several alloy design methodologies. In efforts to understand processing-microstructure-property relationships, different processing routes were employed. The resulting microstructures and mechanical properties are discussed and compared. Plasma arc melted (PAM) samples served to establish baseline, as-cast properties. In addition, a novel processing technique, involving decomposition of a supersaturated and metastable precursor phase during hot isostatic pressing (HIP), was used to produce a refined, equilibrium two-phase microstructure. Quasi-static compression tests as a function of temperature were performed on both alloy types. Different deformation mechanisms were encountered based upon temperature …
Defects And Site Occupancies In Nb-Cr-Ti C15 Laves Phase Alloys, P. G. Kotula, C. B. Carter, Katherine C. Chen, Dan J. Thoma, F. Chu, T. E. Mitchell
Defects And Site Occupancies In Nb-Cr-Ti C15 Laves Phase Alloys, P. G. Kotula, C. B. Carter, Katherine C. Chen, Dan J. Thoma, F. Chu, T. E. Mitchell
Materials Engineering
No abstract provided.
Promoting Excellence In Education With An Outstanding Student Instructor Award Program, Jennifer Kadlowec, Justin Shriver, Trevor S. Harding, Charles Choi
Promoting Excellence In Education With An Outstanding Student Instructor Award Program, Jennifer Kadlowec, Justin Shriver, Trevor S. Harding, Charles Choi
Materials Engineering
The ASEE Student Chapter at the University of Michigan in conjunction with the College of Engineering has developed and organized an annual Outstanding Student Instructor Award in recognition of excellence in engineering education. The award not only acknowledges the outstanding contributions of the individuals selected for the award, but also coincides with the ASEE’s goals of promoting excellence in engineering education and attracting new members. The paper outlines the planning procedures developed since the inception of the award in 1994 and provides suggestions and insights for other ASEE Student Chapters to create and organize such an award.
The Effects Of Beryllium Additions On The Oxidation Of Nickel Aluminide And Titanium Aluminide Based Intermetallics, R. H. Hanrahan Jr., Katherine C. Chen, M. P. Brady
The Effects Of Beryllium Additions On The Oxidation Of Nickel Aluminide And Titanium Aluminide Based Intermetallics, R. H. Hanrahan Jr., Katherine C. Chen, M. P. Brady
Materials Engineering
The effects of Be additions on the oxidation behavior of β-NiAl in moist air at 1000°C and borderline alumina-forming y (TiAI) + Laves Ti-Al-Cr based alloys at 800°C and 1000°C in dry and moist air were investigated. The addition of Be to β-NiAl suppressed the formation of transient alumina, and resulted in the formation of a protective BeAl2O4 spinel phase. In dry air, the addition of Be to the Ti-AI-Cr alloys also resulted in the formation of a protective BeAl2O4 spinel phase. In moist air, only Ti-AlCr- Be alloys with a high Cr content …
Factors Affecting The Room-Temperature Mechanical Properties Of Ticr2-Base Laves Phase Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston
Factors Affecting The Room-Temperature Mechanical Properties Of Ticr2-Base Laves Phase Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston
Materials Engineering
Various effects on the room-temperature mechanical properties of TiCr2-base alloys have been assessed in efforts to improve the toughness of Laves phase intermetallics (AB2). Systematic studies were performed on: (i) single-phase stoichiometric and nonstoichiometric TiCr2, (ii) TiCr2-base ternary Laves phases, and (iii) two-phase binary alloys containing TiCr2. In order to make quantitative comparisons among the different alloys, Vickers indentation was used to obtain hardness and fracture toughness values. Within the single-phase field, constitutional defects accounted for the compositional dependencies of properties, and may aid the synchroshear deformation process. Ternary Laves …
Formation Of A Metastable Bcc Solid Solution And Decomposition To A C15 Laves Phase In Melt-Spun Crnb10Ti10, Katherine C. Chen, P. G. Kotula, F. Chu, Dan J. Thoma
Formation Of A Metastable Bcc Solid Solution And Decomposition To A C15 Laves Phase In Melt-Spun Crnb10Ti10, Katherine C. Chen, P. G. Kotula, F. Chu, Dan J. Thoma
Materials Engineering
A metastable, disordered bcc phase has been formed from the melt in a Cr-rich alloy of the Nb-Cr-Ti system, where large volume fractions of the Laves phase would develop under equilibrium solidification conditions. X-ray diffraction (XRD) studies and lattice constant determinations confirm that the melt-spun ribbons contain a bcc phase beyond its terminal solid solution limits. Solidification pathways are proposed based upon metastable and equilibrium phase diagrams. Microstructures have been studied using optical microscopy, scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Cross-sectional TEM reveals tiny, dispersed Laves phase precipitates within the metastable bcc grains near the chill (wheel) …
Orientation Relationships In The System Nb-Nbcr2, P. G. Kotula, Katherine C. Chen, Dan J. Thoma, F. Chu, T. E. Mitchell
Orientation Relationships In The System Nb-Nbcr2, P. G. Kotula, Katherine C. Chen, Dan J. Thoma, F. Chu, T. E. Mitchell
Materials Engineering
No abstract provided.
Assessment Of The Compositional Influences On The Toughness Of Ticr2-Base Laves Phase Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston
Assessment Of The Compositional Influences On The Toughness Of Ticr2-Base Laves Phase Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston
Materials Engineering
Systematic studies of alloys based on TiCr, have been performed in order to improve the toughness of Laves phase intermetallics. The extent to which alloy compositions and annealing treatments influence the toughness was quantified by Vickers indentation. The single-phase Laves behavior was first established by studying stoichiometric and nonstoichiometric TiCr,. Next, alloying effects were investigated with ternary Laves phases based on TiCr2. Different microstructures of two-phase alloys consisting of (Ti,Cr)-bcc+TiCr2, were also examined. Various toughening theories based on vacancies, site-substitutions, crystal structure (C14, C36, or Cl5) stabilization, and the presence of a …
Evidence Of Heterogeneous Substructure Development During Primary Creep Of Ti-6al-2sn-4zr-2mo, R. W. Hayes, Cecil Rhodes, Blair London
Evidence Of Heterogeneous Substructure Development During Primary Creep Of Ti-6al-2sn-4zr-2mo, R. W. Hayes, Cecil Rhodes, Blair London
Materials Engineering
No Abstract.
Morphology, Deformation, And Defect Structures Of Ticr2 In Ti-Cr Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston
Morphology, Deformation, And Defect Structures Of Ticr2 In Ti-Cr Alloys, Katherine C. Chen, Samuel M. Allen, James D. Livingston
Materials Engineering
The morphologies and defect structures of TiCr2 in several Ti-Cr alloys have been examined by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM), in order to explore the room-temperature deformability of the Laves phase TiCr2. The morphology of the Laves phase was found to be dependent upon alloy composition and annealing temperature. Samples deformed by compression have also been studied using TEM. Comparisons of microstructures before and after deformation suggest an increase in twin, stacking faul4 and dislocation density within the Laves phase, indicating some but not extensive room-temperature deformability.
On The Creep Deformation Of A Cast Near Gamma Tial Alloy Ti-48al-1nb, R. W. Hayes, B. London
On The Creep Deformation Of A Cast Near Gamma Tial Alloy Ti-48al-1nb, R. W. Hayes, B. London
Materials Engineering
The steady-state creep deformation behavior of a cast two phase gamma TiAl alloy having the composition Ti---48Al---1Nb (at.%) has been studied. Tension creep tests using the stress increment technique (θθ2θ3) were conducted over the temperature range of 704–850°C at constant initial applied stress level of 103.4–241.3 MPa. The activation energy for creep over the temperature and stress regime of this study varied 317.5 kJ/mol (137.8 MPa) up to 341.0 kJ/mol (206.8 MPa) with an average value of 326.4 kJ/mol. This is well within the range of values previously measured for gamma TiAl alloys where creep controlled by volume diffusion has …
Steady-State Creep Deformation Of Investment Cast Near-Gamma Titanium Aluminide, D. A. Wheeler, B. London, D. E. Larsen Jr.
Steady-State Creep Deformation Of Investment Cast Near-Gamma Titanium Aluminide, D. A. Wheeler, B. London, D. E. Larsen Jr.
Materials Engineering
No Abstract.
Application Of Optical Emission Diagnostics And Control Related To Semiconductor Processing, Richard N. Savage, Greg C. Viloria
Application Of Optical Emission Diagnostics And Control Related To Semiconductor Processing, Richard N. Savage, Greg C. Viloria
Materials Engineering
This paper discusses and shows applications of optical emission spectroscopy techniques and methods to monitor plasma emissions during semiconductor processing. A brief discussion of the instrumentation that was used and the software to control the instrumentation is presented. Optical emission spectroscopy techniques discussed include chemical species identification in plasma etching, process fingerprinting, contamination detection, endpoint analysis/control, and sputter/deposition plasma monitoring.
Apparatus And Method For Automatically Identifying Chemical Species Within A Plasma Reactor Environment, Richard N. Savage
Apparatus And Method For Automatically Identifying Chemical Species Within A Plasma Reactor Environment, Richard N. Savage
Materials Engineering
A method and apparatus to control the plasma environment in a semiconductor or thin-film fabrication chamber. The apparatus and method include a means for measuring an optical emission spectrum of the chemical species in the plasma and a library containing a multiplicity of predefined spectral patterns. A processor automatically correlates the spectrum with the predefined spectral patterns in the library, and yields a correlation value for all the correlations. A subset of the predefined spectral patterns based upon the highest correlation values are selected and used to identify the chemical species and abundances thereof in the plasma. A comparator compares …
In-Situ Film Thickness Measurements For Real-Time Monitoring And Control Of Advanced Photoresist Track Coating Systems, Richard N. Savage, Thomas E. Metz, Horace O. Simmons
In-Situ Film Thickness Measurements For Real-Time Monitoring And Control Of Advanced Photoresist Track Coating Systems, Richard N. Savage, Thomas E. Metz, Horace O. Simmons
Materials Engineering
This paper explores the methodologies of real-time measurement of photoresist film thickness on silicon wafers using multi-wavelength reflection interferometry. Reflected light from the wafer's surface, containing the interference profile, is collected in-situ via a fiber optic cable and film thickness is determined in real-time via a pattern recognition algorithm. The instrumentation used to make this measurement and its application toward optimizing track performance during spin-coating and back are discussed. Data demonstrating basic thickness versus spin-time and thickness versus bake-time profiles acquired on-line without process disruption are presented along with its utilization toward minimizing process set-up and machine qualification. Moreover, the …
In-Line Photoresist Thickness Monitor, Richard N. Savage, Tom W. Batchelder, Kenneth M. Sautter, Gary H. Memovich
In-Line Photoresist Thickness Monitor, Richard N. Savage, Tom W. Batchelder, Kenneth M. Sautter, Gary H. Memovich
Materials Engineering
An in-line photoresist thickness measuring device wherein a plurality of projection optical fibers are disposed over a wafer processing track for illuminating portions of a wafer as the wafer proceeds along the track. The light scattered back from each illuminated portion is detected by a corresponding plurality of pickup optical fibers and communicated to an optical fiber multiplexer. The multiplexer sequentially selects the optical signal from each pickup optical fiber and communicates the light from the selected pickup optical fiber to a spectrometer. The spectrometer simultaneously diffuses the scattered light into a plurality of light bands, each light band having …
Real-Time, In-Situ Measurement Of Film Thickness And Uniformity During Plasma Ashing Of Photoresist, Richard N. Savage, Horace Simmons, John T. Davies, Thomas Metz
Real-Time, In-Situ Measurement Of Film Thickness And Uniformity During Plasma Ashing Of Photoresist, Richard N. Savage, Horace Simmons, John T. Davies, Thomas Metz
Materials Engineering
This paper will discuss the performance of equipment which monitors and so controls photoresist thickness and uniformity during plasma ashing without interfering with the process. Practical monitoring of a subtractive process of this type is significantly more complex than monitoring deposition processes. An initial absolute thickness measurement is needed. In addition the device must view the layer through a luminous medium and cannot rely on simple optical interference fringe counting. The equipment is self-calibrating and sensitive to layers dnm thick. An application to partial plasma resist ashing in high uniformity equipment will be described. Application to other films (e. g. …
Optical Switch, Richard N. Savage
Optical Switch, Richard N. Savage
Materials Engineering
An optical switch for transmitting light between a first location and a selected one of a plurality of second locations. The switch includes a mirror having a concave, reflective surface and an axis. The switch also includes a plurality of fiber optic cables, one of which is disposed at the first location and the remainder of which are disposed at the second locations, each cable having a light transmission face at their respective locations. The light transmission face at the first location is substantially parallel to the focal plane of the mirror. The light transmission face at each of the …
Using Living Materials To Intervene In The Natural Succession Process To Accelerate The Re-Development Of A Self-Sustaining Ecosystem That Has Been Damaged By Human Intervention, Eric Jorgensen
Materials Engineering
No abstract provided.
New Specimen Design For Studying The Growth Of Small Fatigue Cracks With Surface Acoustic Waves, Blair London
New Specimen Design For Studying The Growth Of Small Fatigue Cracks With Surface Acoustic Waves, Blair London
Materials Engineering
The study of small surface fatigue cracks in AISI 4140 quenched and tempered steel by a nondestructive surface acoustic wave technique is summarized. A novel cantilevered bending, plate-type fatigue specimen is described that is compatible with the acoustic method. Small cracks are initiated from a 25-μm deep surface pit produced by an electrospark machine. The importance of studying these
Applications Of Optical Emission Spectroscopy To Semiconductor Processing, Richard N. Savage, John G. Shabushnig, Paul R. Demko
Applications Of Optical Emission Spectroscopy To Semiconductor Processing, Richard N. Savage, John G. Shabushnig, Paul R. Demko
Materials Engineering
Optical emission spectroscopy (OES) has proven to be a valuable tool in the developmrent and production of state-of-the-art semiconductor devices. Application to the plasma etching of a variety of materials necessary for integrated circuit fabrication is discussed, with particular emphasis placed on etch endpoint analysis. The utility of OES techniques in monitoring photolithographic processes is also presented.
Speciation Of Cr (Iii) And Cr (Vi) Via Reversed Phase Hplc With Inductively Coupled Plasma Emission Spectroscopic Detection (Hplc-Icp)24, Richard N. Savage, I. S. Krull, D. Bushee, R. G. Schleicher, S. B. Smith, Jr.
Speciation Of Cr (Iii) And Cr (Vi) Via Reversed Phase Hplc With Inductively Coupled Plasma Emission Spectroscopic Detection (Hplc-Icp)24, Richard N. Savage, I. S. Krull, D. Bushee, R. G. Schleicher, S. B. Smith, Jr.
Materials Engineering
Chromium ions, viz., chromic (Cr+3 = III) and chromate (Cr+6 = VI), can be reliably, conveniently, reproducibly, and quickly separated and detected by the use of conventional paired-ion, reversed phase (RP) high performance liquid chromatography (HPLC) together with refractive index (RI) and/or inductively coupled plasma emission spectroscopic (ICP) detection. A number of novel paired-ion approaches have now been developed, using PIC A (tetrabutylammonium hydroxide) or PIC B (sodium n-alkyl sulfonate) separately in the mobile phase. This allows for the retention of each Cr species depending on the particular ion pairing reagent being used, while the remaining Cr ion …