Research on Modeling Crystallographic Texture Evolution of Al Alloy 7075

Crystallographic texture is related to the anisotropy or isotropy of material physical properties, including mechanical performance. The crystallographic effect in micromachining is more significant than that in macro-processing owing to that the depth of the cut and the grain size are in the same order. It is of great significance to model the crystallographic texture evolution induced by mechanical and thermal load during micro-machining to investigate the surface integrity and performance of the finished product. This study performed hot deformation experiments of Al alloy 7075 (AA7075) under various input parameters, including the temperature, temperature rate, stain rate, and strain, which was designed using the Taguchi method. Following that, crystallographic orientation of the samples before and after the deformation was tested using electron back-scattered diffraction (EBSD). Then, the crystallographic texture evolution was modeled with the parameters obtained by fitting a part of the experimental data. The crystallographic texture evolution of AA7075 under different levels of input parameters is studied and analyzed. Finally, the sensitivity of crystallographic orientation evolution to the process parameter is analyzed. The results indicate that these four input parameters have a significant impact on some crystallographic texture of the specimens. The proposed model is instructive in the future investigation of micromachining and microstructure evolution.

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MECHANICAL PERFORMANCE OF NOVEL POLYISOBUTYLENE-BASED ELASTOMERIC POLYURETHANES BEFORE AND AFTER HYDROLYSIS

Rubber Chemistry and Technology ◽

10.5254/rct.19.81509 ◽

2019 ◽

Vol 92 (3) ◽

pp. 481-495 ◽

Cited By ~ 1

Author(s):

Jozsef Kantor ◽

Elizabeth A. Collister ◽

Judit E. Puskas ◽

Michael P. Mallamaci ◽

Val C. Comes

Keyword(s):

Mechanical Performance ◽

Hydrolytic Stability ◽

Reaction Times ◽

High Viscosity ◽

Stability Testing ◽

Synthesis Conditions ◽

Before And After ◽

Hard Segments ◽

And Performance ◽

American Society

ABSTRACT The mechanical performance of thermoplastic elastomeric polyurethanes (PUs) before and after hydrolysis is investigated. These new PUs were prepared with a new asymmetric polyisobutylene-diol (PIB-diol), without the use of solvents, and with short reaction times. The PUs were made with dicyclohexylmethane 4,4′-diisocyanate and 1,4-butanediol in the hard segments and poly(hexamethylene carbonate) (PC)-diol and polyisobutylene (PIB)-diol in the soft segments. The functionality of PIB-diol was verified by mass spectrometry. Optimum solventless synthesis conditions and performance were found with a mixture of 50/50 PIB-diol/PC-diol (28.9 wt% PIB in the PU). This PU had 26.03 ± 1.19 MPa tensile strength with 286.92 ± 12.17% elongation before and 16.22 ± 0.65 with 301.17 ± 15.08% elongation after American Society for Testing and Materials (ASTM) hydrolytic stability testing. Importantly, after the hydrolytic stability testing, the stress–strain plot of this PIB–PU was similar to that of the control PC–PU. The PU with 70/30 PIB-diol/PC-diol (41.2 wt% PIB in the PU) performed slightly better but needed solvent during synthesis because of the high viscosity of the mixtures.

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Film Crystallographic Texture and Substrate Urface Roughness in Layered Aluminum Metallization

MRS Proceedings ◽

10.1557/proc-428-261 ◽

1996 ◽

Vol 428 ◽

Cited By ~ 7

Author(s):

K. P. Rodbell ◽

V. Svilan ◽

L. M. Gignac ◽

P. W. Dehaven ◽

R. J. Murphy ◽

...

Keyword(s):

Surface Roughness ◽

Crystallographic Texture ◽

Crystallographic Orientation ◽

Substrate Surface ◽

Deposition Process ◽

Growth Direction ◽

Oxide Surface ◽

Al Alloy ◽

X Ray ◽

Substrate Surface Roughness

AbstractMaterial anisotropy implies that many film properties are affected by crystallographic orientation in the growth direction (out-of-plane texture) and / or in the plane of growth (in-plane texture). Physical vapor deposited (PVD) Ti and Al-alloy films deposited on silicon dioxide substrates typically exhibit strong fiber textures in the growth direction with little in-plane-texture observed. The strength of these fiber textures has been found to vary substantially depending on the details of the deposition process(es) and, to a lesser degree, on any post-deposition anneals. In this paper the role of the substrate surface roughness in defining film texture is reported. It was found that the substrate surface roughness determines the overlying film crystallographic orientation for Ti and Ti/AlCu films deposited on various oxides. Furthermore, it was found that the texture of the initial metal “seed” layer defines the texture in subsequently deposited films (texture inheritance). Modifications to the oxide surface which decrease the surface roughness lead to an improved crystallographic texture in Ti, AlCu, Ti/AlCu and Ti/TiN/AlCu films. Film orientation was determined from crystallographic pole figures measured using x-ray diffraction (XRD). The oxide surface roughness was measured using atomic force microscopy (AFM), transmission electron microscopy (TEM) and glancing incidence x-ray reflectivity (GIXR).

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Study on Hydrophilic Finish and Performance of Polypropylene Spun-Bonded Nonwovens

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.332-334.1308 ◽

2011 ◽

Vol 332-334 ◽

pp. 1308-1311

Author(s):

Jing Yan ◽

Wei Min Kang

Keyword(s):

Mechanical Performance ◽

Technological Condition ◽

Drying Time ◽

Moisture Regain ◽

Hydrophilic Property ◽

Before And After ◽

And Performance ◽

First Time

A new kind of polypropylene spun-bonded nonwovens (PSN) with excellent hydrophilic property was developed after finished with S 6237 hydrophilic agent. The infiltration time (IT) and the runoff (RO) were tested to evaluate the hydrophilicity of the finished PSN. The impacts of different agent concentrations, drying temperatures and drying time on hydrophilicity were investigated and PSN before and after finished were compared concerning softness, air penetrability, moisture regain and stretch performance. The results show that the optimum technological condition for the hydrophilicity is agent concentration: 4 %, drying time: 30s and drying temperatures: 120 °C, and the IT and the RO for the first time are 1.82s and 1.8% respectively. Softness and air penetrability of the finished PSN were improved significantly but mechanical performance was merely decrease a little.

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Analysis of the Failure and Performance Variation Mechanism of MEMS Suspended Inductors with Auxiliary Pillars under High-g Shock

Micromachines ◽

10.3390/mi11110957 ◽

2020 ◽

Vol 11 (11) ◽

pp. 957

Author(s):

Lixin Xu ◽

Yiyuan Li ◽

Jianhua Li

Keyword(s):

Integrated Circuit ◽

Microelectromechanical Systems ◽

Mechanical Performance ◽

Model Parameters ◽

Gravitational Acceleration ◽

Performance Variation ◽

Before And After ◽

And Performance ◽

Variation Mechanism ◽

Rf Performance

Microelectromechanical systems (MEMS) suspended inductors have excellent radio frequency (RF) performance and they are compatible with integrated circuit (IC). They will be shocked during manufacturing, transportation, and operation; in some applications, the shock amplitude can be as high as tens of thousands of gravitational acceleration (g, 9.8 m/s2). High-g shock will lead to the inductor deformation which affects its performance or even failure of the inductor structure. However, few studies have been carried out on the inductors under high-g shock. In this study, a kind of MEMS suspended inductor with excellent RF and mechanical performance is designed and fabricated. The failure and performance variation mechanism of the inductor under high-g shock is analyzed by measuring and comparing the performance measurement results and the π model parameters extraction results of the inductors before and after air cannon shock test. The results show that the increase of energy loss caused by substrate parasitic effect and the properties variation of the coil material affected by high-g shock are the main reasons for the decrease of RF performance parameters, and the critical stress exceeding the interlayer adhesion is the main reason for the failure of the inductor.

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A New Flow Line Function for Modeling Material Trajectory and Textures in Nonequal-Channel Angular Pressing

Advances in Materials Science and Engineering ◽

10.1155/2019/5682585 ◽

2019 ◽

Vol 2019 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

A. Hasani ◽

L. S. Toth ◽

Sh. Mardokh Rouhani

Keyword(s):

Plastic Deformation ◽

Crystallographic Texture ◽

Mechanical Performance ◽

Flow Line ◽

Texture Evolution ◽

Pure Aluminum ◽

Deformation Field ◽

Plastic Deformation Zone ◽

Flow Function ◽

Angular Pressing

One of the most applied severe plastic deformation processes is ECAP (equal-channel angular pressing) which is suitable to produce ultrafine-grained metallic materials with high mechanical performance. A variant of the ECAP process was proposed in 2009, which consists in reducing the diameter of the exit channel of the die; it is named the nonequal-channel angular pressing (NECAP) process. A flow line function was also proposed to describe the material flow and the deformation field during NECAP. In the present work, an improved version of that flow function is presented containing two additional parameters compared to the previously proposed function. The new parameters permit to control precisely the shapes and the positions of the flow lines. The new flow function was applied to 90° NECAP of commercially pure aluminum to characterize the deformation field and the extent of the plastic deformation zone. The crystallographic texture evolution is also simulated using the new function. Excellent agreements with experiments were obtained for both the flow line trajectories and the crystallographic texture.

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The Influence of Cognitive and Affective Reactions to Feedback on Subsequent Goals

European Psychologist ◽

10.1027/1016-9040/a000011 ◽

2010 ◽

Vol 15 (2) ◽

pp. 121-131 ◽

Cited By ~ 20

Author(s):

Remus Ilies ◽

Timothy A. Judge ◽

David T. Wagner

Keyword(s):

Performance Feedback ◽

Business School ◽

Structural Equation ◽

Emotional Reactions ◽

Equation Model ◽

Proposed Model ◽

And Performance ◽

Dispositional Measure ◽

The Relationship ◽

Reactions To Feedback

This paper focuses on explaining how individuals set goals on multiple performance episodes, in the context of performance feedback comparing their performance on each episode with their respective goal. The proposed model was tested through a longitudinal study of 493 university students’ actual goals and performance on business school exams. Results of a structural equation model supported the proposed conceptual model in which self-efficacy and emotional reactions to feedback mediate the relationship between feedback and subsequent goals. In addition, as expected, participants’ standing on a dispositional measure of behavioral inhibition influenced the strength of their emotional reactions to negative feedback.

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An Analytical Transient Tire Model

Tire Science and Technology ◽

10.2346/1.2135231 ◽

2001 ◽

Vol 29 (2) ◽

pp. 108-132 ◽

Cited By ~ 1

Author(s):

A. Ghazi Zadeh ◽

A. Fahim

Keyword(s):

Transient Behavior ◽

Stability Control ◽

Vehicle Stability ◽

Tire Model ◽

Steering Angle ◽

First Order ◽

Vehicle Stability Control ◽

Proposed Model ◽

Depth Study ◽

And Performance

Abstract The dynamics of a vehicle's tires is a major contributor to the vehicle stability, control, and performance. A better understanding of the handling performance and lateral stability of the vehicle can be achieved by an in-depth study of the transient behavior of the tire. In this article, the transient response of the tire to a steering angle input is examined and an analytical second order tire model is proposed. This model provides a means for a better understanding of the transient behavior of the tire. The proposed model is also applied to a vehicle model and its performance is compared with a first order tire model.

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Low-pressure cold metal spray coatings for repair and protection of marine components

10.24868/issn.2515-818x.2018.043 ◽

2018 ◽

Author(s):

M Pal

Keyword(s):

Marine Environment ◽

Alloy Coating ◽

Al Alloy ◽

Metallic Coatings ◽

Material State ◽

Paint Coatings ◽

And Performance ◽

Cuzn Alloy ◽

Cold Metal ◽

Metal Spray

The marine environment is hostile to most engineering materials, a combination of in-service wear and exposure to marine environment leads to an accelerated material degradation. Insufficient or poor protection of the substrates further assists the accelerated material degradation in marine environment. There is a direct relationship between the material-state of a ship and its operational capability, readiness, and service life. The current state-of-the-art practice is to use paint-based coatings to maintain the material-state of ships. However, the protection offered by paint coatings is usually brief due to inherent permeability and low damage tolerance of these coatings. For this reason, the paint coatings require renewal at regular intervals, typically less than 5-years, to maintain a minimum level of protection from the marine environment. The need for regular painting of ships results in a significant negative impact on the through-life availability, operational capability/readiness, and the cost of maintenance/operation of naval ships. Therefore, the fleet owners and operators should look beyond the conventional paint-based coatings to achieve significant breakthrough improvements in maintaining and enhancing the material-state of naval ships. Metallic coatings, if selected and applied appropriately, will outperform the paint coatings in the marine environment. Historically, the cost and performance of metallic coatings, mainly thermal metal spray (TMS) coatings, prevented their widespread use in the marine industry. The TMS coatings also have their own inherent application and performance related limitations that are widely reported in the literature. However, the cold metal spray (CMS) coating process can overcome the application and performance related limitations that are typically associated with the TMS coatings, therefore creating an opportunity for widespread use of metallic coatings in shipbuilding and fleet upkeep/maintenance. In this paper, the ability of low-pressure (LP-CMS) coatings to repair and reclaim damaged marine components, and application of functional coatings to improve in-service damage tolerance of the damaged/new components is investigated. The results of the investigation show that two LP-CMS coatings, Al-alloy and CuZn-alloy, can be used to repair and preserve both new and damaged components. The accelerated salt-spray and natural immersion corrosion testing of the LP-CMS coatings showed that each coating will be better suited to a particular operational environment, i.e. CuZn-alloy coating performed well in both immersion and atmospheric corrosion environments, whereas Al-alloy coating performed well only in atmospheric corrosion environment.

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Effects of cooled floor pads combined with chilled drinking water on behavior and performance of lactating sows under heat stress

Journal of Animal Science ◽

10.1093/jas/skab066 ◽

2021 ◽

Vol 99 (3) ◽

Author(s):

Y Zhu ◽

L J Johnston ◽

M H Reese ◽

E S Buchanan ◽

J E Tallaksen ◽

...

Keyword(s):

Drinking Water ◽

Heat Stress ◽

Respiration Rate ◽

Rectal Temperature ◽

Time Budget ◽

Video Recording ◽

Lactating Sows ◽

Before And After ◽

And Performance ◽

Drinking Frequency

Abstract This study was conducted to evaluate whether cooled floor pads combined with chilled drinking water could alleviate negative impacts of heat stress on lactating sows. Thirty sows (Landrace × Yorkshire, Parity = 1 to 6) were housed in individual farrowing stalls in two rooms with temperatures being controlled at 29.4°C (0700–1900 hours) and 23.9°C (1900–0700 hours). Sows in one room (Cool), but not in the other room (Control) were provided cooled floor pads (21–22°C) and chilled drinking water (13–15°C). Behavior of sows (15 sows/treatment) was video recorded during farrowing, and days 1, 3, 7, 14, and 21 after farrowing. Videos were viewed continuously to register the birth time of each piglet, from which total farrowing duration and birth intervals were calculated. The number of drinking bouts and the duration of each drinking bout were registered for each sow through viewing videos continuously for 2 h (1530–1730 hours) each video-recording day. Postures (lying laterally, lying ventrally, sitting, and standing) were recorded by scanning video recordings at 5-min intervals for 24 h each video-recording day, and time budget for each posture was calculated. Rectal temperature and respiration rate were measured for all sows the day before and after farrowing, and then once weekly. Sow and litter performance was recorded. Data were analyzed using the Glimmix procedure of SAS. The cooling treatment did not affect sow behavior or litter performance. Sows in the Cool room had lower rectal temperature (P = 0.03) and lower respiration rate (P < 0.001), consumed more feed (P = 0.03), tended to have reduced weight loss (P = 0.07), and backfat loss (P = 0.07) during lactation than sows in the Control room. As lactation progressed, sows increased drinking frequency (P < 0.001) and time spent lying ventrally (P < 0.0001), standing (P < 0.001), and sitting (P < 0.0001), and decreased time spent lying laterally (P < 0.0001) in both Cool and Control rooms. While cooled floor pads combined with chilled drinking water did not affect sow behavior, they did alleviate heat stress partially, as indicated by decreased rectal temperature, respiration rate, weight, and backfat loss, and increased feed intake in lactating sows.

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Natural Disasters Intensity Analysis and Classification Based on Multispectral Images Using Multi-Layered Deep Convolutional Neural Network

Sensors ◽

10.3390/s21082648 ◽

2021 ◽

Vol 21 (8) ◽

pp. 2648

Author(s):

Muhammad Aamir ◽

Tariq Ali ◽

Muhammad Irfan ◽

Ahmad Shaf ◽

Muhammad Zeeshan Azam ◽

...

Keyword(s):

Neural Network ◽

Convolutional Neural Network ◽

Natural Disasters ◽

Deep Convolutional Neural Network ◽

Multispectral Images ◽

Learning Techniques ◽

Proposed Model ◽

Disaster Intensity ◽

And Performance

Natural disasters not only disturb the human ecological system but also destroy the properties and critical infrastructures of human societies and even lead to permanent change in the ecosystem. Disaster can be caused by naturally occurring events such as earthquakes, cyclones, floods, and wildfires. Many deep learning techniques have been applied by various researchers to detect and classify natural disasters to overcome losses in ecosystems, but detection of natural disasters still faces issues due to the complex and imbalanced structures of images. To tackle this problem, we propose a multilayered deep convolutional neural network. The proposed model works in two blocks: Block-I convolutional neural network (B-I CNN), for detection and occurrence of disasters, and Block-II convolutional neural network (B-II CNN), for classification of natural disaster intensity types with different filters and parameters. The model is tested on 4428 natural images and performance is calculated and expressed as different statistical values: sensitivity (SE), 97.54%; specificity (SP), 98.22%; accuracy rate (AR), 99.92%; precision (PRE), 97.79%; and F1-score (F1), 97.97%. The overall accuracy for the whole model is 99.92%, which is competitive and comparable with state-of-the-art algorithms.

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