scholarly journals Evolution of Interfacial Friction Angle and Contact Area of Polymer Pellets during the Initial Stage of Ultrasonic Plasticization

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2103
Author(s):  
Bingyan Jiang ◽  
Yang Zou ◽  
Guomeng Wei ◽  
Wangqing Wu
Keyword(s):  
Contact Area ◽  
Frictional Heating ◽  
Friction Angle ◽  
Interfacial Friction ◽  
Initial Stage ◽  
Friction Heating ◽  
Critical Boundary ◽  
Generation Mechanisms ◽  
Vibration Time

Interfacial friction heating is one of the leading heat generation mechanisms during the initial stage of ultrasonic plasticization of polymer pellets, which has a significant influence on the subsequent viscoelastic heating according to our previous study. The interfacial friction angle and contact area of polymer pellets are critical boundary conditions for the analysis of interfacial frictional heating of polymer pellets. However, the duration of the interfacial friction heating is extremely short in ultrasonic plasticization, and the polymer pellets are randomly distributed in the cylindrical barrel, resulting in the characterization of the distribution of the interfacial friction angle and contact area to be a challenge. In this work, the interfacial friction angle of the polymer pellets in the partially plasticized samples of polymethyl methacrylate (PMMA), polypropylene (PP), and nylon66 (PA66) were characterized by a super-high magnification lens zoom 3D microscope. The influence of trigger pressure, plasticizing pressure, ultrasonic amplitude, and vibration time on the interfacial friction angle and the contact area of the polymer pellets were studied by a single factor experiment. The results show that the compaction degree of the plasticized samples could be enhanced by increasing the level of the process parameters. With the increasing parameter level, the proportion of interfacial friction angle in the range of 0–10° and 80–90° increased, while the proportion in the range of 30–60° decreased accordingly. The proportion of the contact area of the polymer pellets was increased up to 50% of the interfacial friction area which includes the upper, lower, and side area of the cylindrical plasticized sample.

Characterization of the Initial Stage of Discharges between Micro-gap in Liquid using Optical Measurement

2010 ◽  
Vol 130 (4) ◽  
pp. 313-318
Author(s):  
Makoto Kanemaru ◽  
Shohei Sorimachi ◽  
Shinji Ibuka ◽  
Shozo Ishii
Keyword(s):  
Optical Measurement ◽  
Initial Stage

In-Situ Characterization of Growth and Intermixing at a Heteroepitaxial Interface: Fe on Au(001)

1993 ◽  
Vol 318 ◽  
Author(s):  
Q. Jiang ◽  
A. Chan ◽  
Y.-L. He ◽  
G.-C. Wang
Keyword(s):  
Elevated Temperatures ◽  
Chemical Elements ◽  
Background Intensity ◽  
In Situ Characterization ◽  
Initial Stage ◽  
Monolayer Growth ◽  
Low Energy Electron ◽  
Energy Dependent

ABSTRACTThe growth and chemical intermixing of submonolayer and a few monolayer thick Fe films on a Au(001) surface was studied by High Resolution Low Energy Electron Diffraction (HRLEED) technique. Through the analysis of the energy dependent angular profiles as a function of time, we obtained the distribution of islands and distribution of spacings during submonolayer growth. The interference of electron waves from different chemical elements in terraces at different heights in the surface contributes to the background intensity and broadening in the angular profiles of diffraction beams. A subsurface Fe capped by Au islands as a result of atomic place exchange was observed at the initial stage of monolayer growth. From the energy dependent angular profiles as a function of temperature, we determine the quantitative change of inhomogeneity length (∼20 Å) at the interface of ultrathin films at elevated temperatures due to intermixing.

scholarly journals Characterization of the initial stage of negative rocket-triggered lightning

1999 ◽  
Vol 104 (D4) ◽  
pp. 4213-4222 ◽  
Author(s):  
D. Wang ◽  
V. A. Rakov ◽  
M. A. Uman ◽  
M. I. Fernandez ◽  
K. J. Rambo ◽  
...  
Keyword(s):  
Initial Stage ◽  
Triggered Lightning

Application of the Continuous Rheoconversion Process (CRP) to Low Temperature HPDC-Part I: Microstructure

2006 ◽  
Vol 116-117 ◽  
pp. 402-405 ◽  
Author(s):  
Qin Yue Pan ◽  
Stuart Wiesner ◽  
Diran Apelian
Keyword(s):  
Low Temperature ◽  
Scale Up ◽  
Microstructural Characterization ◽  
Industrial Applications ◽  
Primary Phase ◽  
Heat Extraction ◽  
Initial Stage ◽  
Fraction Solid ◽  
Die Castings

The continuous rheoconversion process (CRP) is a novel slurry-on-demand process that was developed at MPI/WPI in 2002. The process is based on a passive liquid mixing technique in which the nucleation and growth of the primary phase are controlled using a specially designed “reactor”. The reactor provides heat extraction, copious nucleation, and forced convection during the initial stage of solidification, thus leading to the formation of globular structures. This paper presents our recent work on the scale-up of the CRP for industrial applications. Specifically, we demonstrate an important application of the CRP to low temperature (low fraction solid) HPDC. In Part I of this paper, we present salient results on microstructural characterization of CRP processed castings vs. conventional die castings.

Observation of Growth Front on the Initial Stage of Goss Abnormally-Growing Grain in Fe-3%Si Steel

2013 ◽  
Vol 753 ◽  
pp. 307-310
Author(s):  
Kyung Jun Ko ◽  
Jong Tae Park ◽  
Chan Hee Han
Keyword(s):  
Solid State ◽  
Grain Boundary ◽  
Three Dimensional ◽  
Secondary Recrystallization ◽  
Growth Front ◽  
Very High Frequency ◽  
Grain Boundary Mobility ◽  
Initial Stage ◽  
The Matrix

During abnormal grain growth, a few Goss grains grow exclusively fast and consume the matrix grains. The Goss abnormally-growing grain (AGG) has peculiar features which are irregular grain boundaries and very high frequency of peninsular grains nearby the growth front of AGG and island grains trapped inside AGG. These features might provide a clue for clarifying the mechanism of Goss AGG. The experimentally-observed microstructural feature and grain boundary characterization of Goss were approached by the solid-state wetting mechanism. In this study, observing the three-dimensional wetting morphology in serial section images of Goss AGG by EBSD, we report some direct microstrucrual evidence supporting solid-state wetting mechanism for Goss AGG. The solid-state wetting mechanism for the evolution of the Goss AGG in Fe-3%Si steel explains the microstructural features evolved during secondary recrystallization, which cannot be approached by the conventional theories based on the grain boundary mobility.

scholarly journals Shear Strength Characterization of Bauxite Deposits in Kuantan, East Coast Malaysia

2019 ◽  
Vol 8 (3S3) ◽  
pp. 404-407
Keyword(s):  
Shear Strength ◽  
Moisture Content ◽  
East Coast ◽  
Field Performance ◽  
Friction Angle ◽  
Parent Rock ◽  
Index Tests ◽  
Strength Characterization ◽  
The Relationship

Engineering characterization which are useful for "temperate" zone soils usually fail to predict the field performance of bauxitic soils, because the index tests upon which the characterization are based are not always reproducible for bauxitic soils. Fifteen (15) bauxitic soil of undisturbed and disturbed samples from 3 distinct sites in Kuantan, all derived from basalt parent rock but representing various stages of weathering were subjected to engineering and mineralogic tests. Values for cohesion and friction angles are evaluated. Soils from Semambu has the highest moisture content of 33.27%, the cohesion value is however lower compared to Bukit Goh which has moisture content of 21.74%. Study are further done to discover the relationship with cohesion and friction angles. Thus, by measuring the cohesion and friction angle can evaluate the performance of bauxite shear strength.

scholarly journals Business Risk and Project Management in Civil Construction Branch

2019 ◽  
Vol 1 (1) ◽  
pp. 324-331
Author(s):  
Marek Winiarski ◽  
Mariusz Urbański ◽  
Riffat Faizan
Keyword(s):  
Project Management ◽  
Construction Industry ◽  
Construction Sector ◽  
Business Risk ◽  
Final Phase ◽  
Economic Space ◽  
Initial Stage ◽  
Time Frames ◽  
Final Effect

AbstractProject management is general planning, coordination and inspection of the project, from the initial stage all the way to final phase, its purpose is an accomplishment of the accepted task and creation of the functional final effect, without exceeding established costs, time-frames and fulfillment of required standards of the quality. The present article was devoted to the issue of the project management in the construction sector in order to reduce the business risk. The study is based on literature examinations with an own methodological solution for project management in the construction industry. After introducing a set of definitions of the project and describing the concept of project management, a characterization of the project management in the construction industry and its effects in the economic space were described

scholarly journals Study of Wire Deformation Characterization and Size Effects during the Micro-Flat-Rolling Process

Metals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 405 ◽  
Author(s):  
Haibo Xie ◽  
Ken-ichi Manabe ◽  
Zhengyi Jiang
Keyword(s):  
Surface Roughness ◽  
Contact Area ◽  
Rolling Process ◽  
Lateral Spread ◽  
Curvature Radius ◽  
Element Simulation ◽  
Flat Rolling ◽  
Set Up ◽  
Rolling Deformation

A comprehensive research on the flat rolling deformation characterization of microwire has been conducted systematically through finite element simulation and testified by the results from the experimental analysis. The obtained results are compared in terms of lateral spread, geometrical characteristic, contact area width and surface roughness considering the effects of pass reduction and initial wire diameter. The size effect has been identified and surface layer modeling has been set up based on surface grain share and grain size distribution. The numerical method combined with varied flow stress has been verified by experimental value with a maximum difference of 3.7% for the 1.5 mm wire. With the increase of the height reduction, the curvature radius is decreased while the lateral spread and contact area width are increased. Surface roughness evolution in the range of 0.52–0.85 µm for the rolled wire has also been investigated.

scholarly journals Study on the Mechanism of Interfacial Friction Heating in Polymer Ultrasonic Plasticization Injection Molding Process

Polymers ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 1407 ◽  
Author(s):  
Tao Peng ◽  
Bingyan Jiang ◽  
Yang Zou
Keyword(s):  
Injection Molding ◽  
Heating Temperature ◽  
Fem Simulation ◽  
Polymeric Materials ◽  
Interfacial Friction ◽  
Heating Process ◽  
Injection Molding Process ◽  
Ultrasonic Frequency ◽  
Friction Heating ◽  
Micro Parts

Ultrasonic Plasticization Injection Molding (UPIM) is an effective way to manufacture polymeric micro parts and has great potential for energy saving with processing polymeric materials of a small amount. To better control the UPIM process and improve the quality of micro parts, it is necessary to study the heat generation mechanism. In this paper, the interfacial friction heating process of UPIM was studied by finite element (FEM) simulation and experiment, and the temperature change in the friction interface was estimated. Then, the effects of different process parameters such as ultrasonic frequency and ultrasonic amplitude on the friction heating process were analyzed. The results showed that the rising trend of friction heating temperature was transient (finished within 1 s), and the change trend of FEM simulation was consistent with experimental results. Adjusting ultrasonic frequency and amplitude has a significant influence on the friction heating process. Increasing the ultrasonic frequency and amplitude can improve the efficiency of friction heating.

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