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Wu W, Shan Z, Qiang Y, Zhou M. Transient viscoelastic heating characteristics of polyethene under high frequency hammering during ultrasonic plasticizing. ULTRASONICS 2023; 133:107055. [PMID: 37269683 DOI: 10.1016/j.ultras.2023.107055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Revised: 04/06/2023] [Accepted: 05/23/2023] [Indexed: 06/05/2023]
Abstract
As a polymer molding technology developed in recent years, ultrasonic plasticizing micro-injection molding has great advantages in the manufacture of micro-nano parts by virtue of low energy consumption, less material waste and reduced filling resistance. However, the process and mechanism of transient viscoelastic heating for polymers under ultrasonic high-frequency hammering are unclear. The innovation of this research is that a combination of experiment and MD (molecular dynamics) simulation was adopted to study the transient viscoelastic thermal effect and microscopic behavior of polymers with different process parameters. To be more specific, a simplified heat generation model was first established and high-speed infrared thermal imaging equipment was applied to collect temperature data. Then, a single factor experiment was conducted to investigate the heat generation of a polymer rod with various process parameters (plasticizing pressure, ultrasonic amplitude and ultrasonic frequency). Finally, the thermal behavior during the experiment was supplemented and explained by MD simulation. The results showed that changes in ultrasonic process parameters produce different forms of heat generation, and there are three forms of heat generation, which are dominant heat generation at the ultrasonic sonotrode head end, dominant heat generation at the plunger end, and simultaneous heat generation at the ultrasonic sonotrode head end and the plunger end.
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Affiliation(s)
- Wangqing Wu
- State Key Laboratory of Precision Manufacturing for Extreme Service Performance, School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
| | - Zhiying Shan
- State Key Laboratory of Precision Manufacturing for Extreme Service Performance, School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
| | - Yuanbao Qiang
- State Key Laboratory of Precision Manufacturing for Extreme Service Performance, School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
| | - Mingyong Zhou
- State Key Laboratory of Precision Manufacturing for Extreme Service Performance, School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China.
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Chen S, Bao X, Wang Z, Rong X, Zhang X, Li C, Wang X, Wei L. Comparative study on the effects of water pressure on water absorption of ultra‐high molecular weight polyethylene and polyformaldehyde. J Appl Polym Sci 2022. [DOI: 10.1002/app.52783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Song Chen
- College of Mechanical Engineering Hunan Institute of Science and Technology Yueyang China
| | - Xiangcai Bao
- College of Mechanical Engineering Hunan Institute of Science and Technology Yueyang China
| | - Zhiheng Wang
- College of Mechanical Engineering Hunan Institute of Science and Technology Yueyang China
| | - Xiangbin Rong
- College of Mechanical Engineering Hunan Institute of Science and Technology Yueyang China
| | - Xiaohong Zhang
- College of Mechanical Engineering Hunan Institute of Science and Technology Yueyang China
| | - Chao Li
- College of Mechanical Engineering Hunan Institute of Science and Technology Yueyang China
| | - Xinyu Wang
- College of Mechanical Engineering Hunan Institute of Science and Technology Yueyang China
| | - Lei Wei
- College of Mechanical Engineering Hunan Institute of Science and Technology Yueyang China
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Li K, Li Z, Liu J, Wen S, Liu L, Zhang L. Designing the cross-linked network to tailor the mechanical fracture of elastomeric polymer materials. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.124931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Qiang Y, Wu W, Lu J, Jiang B, Ziegmann G. Progressive Molecular Rearrangement and Heat Generation of Amorphous Polyethene Under Sliding Friction: Insight from the United-Atom Molecular Dynamics Simulations. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2020; 36:11303-11315. [PMID: 32878446 DOI: 10.1021/acs.langmuir.0c01949] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Frictional heat has been widely used in various polymer-based advanced manufacturing. The fundamental understanding of the thermodynamics of the interfacial friction of polymer bulk materials can help to avoid compromising the process controllability. In this work, we have performed united-atom molecular dynamics (MD) simulations to reveal the interfacial friction heating mechanism of amorphous polyethene (PE) in both the single sliding friction (SSF) and reciprocating sliding friction (RSF) modes. Different from the traditional view that the plastic deformation was the primary source of heat generation, the RSF process with no apparent plastic deformation in this work shows a better heat generation performance than SSF, where plastic deformation dominated the friction process. Our analysis uncovers that the mechanism of the interfacial friction heating enhancement in RSF can be attributed to the concentrated high-frequency chain motion related to molecular rearrangement, which is not clearly related to the deformation degree.
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Affiliation(s)
- Yuanbao Qiang
- State Key Laboratory of High Performance Complex Manufacturing, Central South University, Lushan South Road 932, Changsha 410083, China
- School of Mechanical and Electrical Engineering, Central South University, Lushan South Road 932, Changsha 410083, China
| | - Wangqing Wu
- State Key Laboratory of High Performance Complex Manufacturing, Central South University, Lushan South Road 932, Changsha 410083, China
- School of Mechanical and Electrical Engineering, Central South University, Lushan South Road 932, Changsha 410083, China
| | - Jin Lu
- State Key Laboratory of High Performance Complex Manufacturing, Central South University, Lushan South Road 932, Changsha 410083, China
- School of Mechanical and Electrical Engineering, Central South University, Lushan South Road 932, Changsha 410083, China
| | - Bingyan Jiang
- State Key Laboratory of High Performance Complex Manufacturing, Central South University, Lushan South Road 932, Changsha 410083, China
- School of Mechanical and Electrical Engineering, Central South University, Lushan South Road 932, Changsha 410083, China
| | - Gerhard Ziegmann
- Institute of Polymer Materials and Plastics Engineering, Clausthal University of Technology, Clausthal-Zellerfeld 38678, Germany
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Miura T, Funada M, Shimoi Y, Morita H. Simulation Study of the Effects of Nanoporous Structures on Mechanical Properties at Polymer-Metal Interfaces. J Phys Chem B 2019; 123:1161-1170. [PMID: 30677295 DOI: 10.1021/acs.jpcb.8b10556] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We investigated the effect of nanopores on the adhesion behavior at polymer-metal interfaces by molecular dynamics simulation. The effects of shear and extension behavior were examined. In the shear mode, samples with porous substrates showed larger shear forces than those with flat substrates. Meanwhile, the breaking strengths in the extension mode were almost the same for systems with flat and porous substrates. The similar behavior in the extension mode was ascribed to the formation of voids in the polymer layer, which was related to the increase of total system volume and not affected by the presence of pores. We also investigated the relationship between the mechanical properties of polymer-metal interfaces in the shear mode and pore size in detail. Even a very shallow pore with a depth of 0.5 nm produced a large shear force comparable to that of a pore with a depth of 2.0 nm. The shear force increased gradually as the pore diameter became wider. These simulation results revealed that the adhesion forces between polymers and rough metal surfaces are not simply related to the interface area but depend on the pulling mode, pore size, and polymer chain length in a complicated manner.
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Affiliation(s)
- Toshiaki Miura
- National Institute of Advanced Industrial Science and Technology (AIST) , 1-1-1 Umezono , Tsukuba , Ibaraki 305-8568 , Japan
| | - Maki Funada
- Innovative Structural Materials Association (ISMA) , AIST Central 5, 1-1-1 Higashi , Tsukuba , Ibaraki 305-8565 , Japan
| | - Yukihiro Shimoi
- National Institute of Advanced Industrial Science and Technology (AIST) , 1-1-1 Umezono , Tsukuba , Ibaraki 305-8568 , Japan
| | - Hiroshi Morita
- National Institute of Advanced Industrial Science and Technology (AIST) , 1-1-1 Umezono , Tsukuba , Ibaraki 305-8568 , Japan
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Lorenz B, Persson BNJ, Fortunato G, Giustiniano M, Baldoni F. Rubber friction for tire tread compound on road surfaces. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2013; 25:095007. [PMID: 23334507 DOI: 10.1088/0953-8984/25/9/095007] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We have measured the surface topography and calculated the surface roughness power spectrum for an asphalt road surface. For the same surface we have measured the friction for a tire tread compound for velocities 10(-6) m s(-1) < v < 10(-3) m s(-1) at three different temperatures (at -8 °C, 20 °C and 48 °C). The friction data was shifted using the bulk viscoelasticity shift factor a(T) to form a master curve. We have measured the effective rubber viscoelastic modulus at large strain and calculated the rubber friction coefficient (and contact area) during stationary sliding and compared it to the measured friction coefficient. We find that for the low velocities and for the relatively smooth road surface we consider, the contribution to friction from the area of real contact is very important, and we interpret this contribution as being due to shearing of a very thin confined rubber smear film.
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Affiliation(s)
- B Lorenz
- IFF, FZ-Jülich, D-52425 Jülich, Germany, EU.
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Sivebaek IM, Samoilov VN, Persson BNJ. Effective viscosity of confined hydrocarbons. PHYSICAL REVIEW LETTERS 2012; 108:036102. [PMID: 22400762 DOI: 10.1103/physrevlett.108.036102] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Indexed: 05/13/2023]
Abstract
We present molecular dynamics friction calculations for confined hydrocarbon films with molecular lengths from 20 to 1400 carbon atoms. We find that the logarithm of the effective viscosity η(eff) for nanometer-thin films depends linearly on the logarithm of the shear rate: log η(eff)=C-nlog ̇γ, where n varies from 1 (solidlike friction) at very low temperatures to 0 (Newtonian liquid) at very high temperatures, following an inverse sigmoidal curve. Only the shortest chain molecules melt, whereas the longer ones only show a softening in the studied temperature interval 0<T<900 K. The results are important for the frictional properties of very thin (nanometer) films and to estimate their thermal durability.
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Lorenz B, Persson BNJ, Dieluweit S, Tada T. Rubber friction: comparison of theory with experiment. THE EUROPEAN PHYSICAL JOURNAL. E, SOFT MATTER 2011; 34:1-11. [PMID: 22139094 DOI: 10.1140/epje/i2011-11129-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2011] [Accepted: 10/20/2011] [Indexed: 05/31/2023]
Abstract
We have measured the friction force acting on a rubber block slid on a concrete surface. We used both unfilled and filled (with carbon black) styrene butadiene (SB) rubber and have varied the temperature from -10 °C to 100 °C and the sliding velocity from 1 μm/s to 1000 μm/s. We find that the experimental data at different temperatures can be shifted into a smooth master-curve, using the temperature-frequency shifting factors obtained from measurements of the bulk viscoelastic modulus. The experimental data has been analyzed using a theory which takes into account the contributions to the friction from both the substrate asperity-induced viscoelastic deformations of the rubber, and from shearing the area of real contact. For filled SB rubber the frictional shear stress σ(f) in the area of real contact results mainly from the energy dissipation at the opening crack on the exit side of the rubber-asperity contact regions. For unfilled rubber we instead attribute σ(f) to shearing of a thin rubber smear film, which is deposited on the concrete surface during run in. We observe very different rubber wear processes for filled and unfilled SB rubber, which is consistent with the different frictional processes. Thus, the wear of filled SB rubber results in micrometer-sized rubber particles which accumulate as dry dust, which is easily removed by blowing air on the concrete surface. This wear process seams to occur at a steady rate. For unfilled rubber a smear film forms on the concrete surface, which cannot be removed even using a high-pressure air stream. In this case the wear rate appears to slow down after some run in time period.
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