Discharge and densification in the spark plasma sintering of quasicrystal particles
To investigate the micromechanisms involved in the spark plasma sintering of quasicrystals, thin foils were extracted from samples by focused ion beam at the interrupted states and analysed by transmission electron microscopy for the first time. Material jets are present between adjacent particles,...
| Main Authors: | , , , , , , |
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| Other Authors: | |
| Format: | Journal Article |
| Language: | English |
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2021
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| Online Access: | https://hdl.handle.net/10356/151240 |
| _version_ | 1811697311464554496 |
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| author | Li, Ruitao Liu, Qing Tian, Lihui Wang, Yun Khor, Khiam Aik Zhang, Di Dong, Zhili |
| author2 | School of Materials Science and Engineering |
| author_facet | School of Materials Science and Engineering Li, Ruitao Liu, Qing Tian, Lihui Wang, Yun Khor, Khiam Aik Zhang, Di Dong, Zhili |
| author_sort | Li, Ruitao |
| collection | NTU |
| description | To investigate the micromechanisms involved in the spark plasma sintering of quasicrystals, thin foils were extracted from samples by focused ion beam at the interrupted states and analysed by transmission electron microscopy for the first time. Material jets are present between adjacent particles, indicating the occurrence of discharge/plasma. Surficial material melts first due to discharge and the liquid sputters as a result of the action of electric field, forming material jets. Discharge occurs in all the cavities with the largest gap size of 60 nm. Gap size is a deciding factor for the formation of material jets: Thick jets are only formed in narrow gaps (< 20 nm), while very thin jets or even no jets are present in wide gaps (> 20 nm). A low voltage (< 0.016 V) is needed to trigger the discharge, and it is inferred that quantum tunnelling and thermal excitation promote the formation of discharge within nanopores at relatively high temperatures. Discharge contributes very little to the densification, while the plastic deformation, meditated by a unique type of defect—metadislocations, is the dominant mechanism for it. The phase transformation of icosahedral Al–Cu–Fe–Cr to its crystalline approximants is accompanied by the formation of planar faults. |
| first_indexed | 2024-10-01T07:53:15Z |
| format | Journal Article |
| id | ntu-10356/151240 |
| institution | Nanyang Technological University |
| language | English |
| last_indexed | 2024-10-01T07:53:15Z |
| publishDate | 2021 |
| record_format | dspace |
| spelling | ntu-10356/1512402021-06-09T07:53:57Z Discharge and densification in the spark plasma sintering of quasicrystal particles Li, Ruitao Liu, Qing Tian, Lihui Wang, Yun Khor, Khiam Aik Zhang, Di Dong, Zhili School of Materials Science and Engineering School of Mechanical and Aerospace Engineering Temasek Laboratories @ NTU Research Techno Plaza Engineering::Materials Electric-field Mechanisms To investigate the micromechanisms involved in the spark plasma sintering of quasicrystals, thin foils were extracted from samples by focused ion beam at the interrupted states and analysed by transmission electron microscopy for the first time. Material jets are present between adjacent particles, indicating the occurrence of discharge/plasma. Surficial material melts first due to discharge and the liquid sputters as a result of the action of electric field, forming material jets. Discharge occurs in all the cavities with the largest gap size of 60 nm. Gap size is a deciding factor for the formation of material jets: Thick jets are only formed in narrow gaps (< 20 nm), while very thin jets or even no jets are present in wide gaps (> 20 nm). A low voltage (< 0.016 V) is needed to trigger the discharge, and it is inferred that quantum tunnelling and thermal excitation promote the formation of discharge within nanopores at relatively high temperatures. Discharge contributes very little to the densification, while the plastic deformation, meditated by a unique type of defect—metadislocations, is the dominant mechanism for it. The phase transformation of icosahedral Al–Cu–Fe–Cr to its crystalline approximants is accompanied by the formation of planar faults. Ministry of Education (MOE) This project was supported by the Ministry of Education, Singapore (AcRF Tier 1, Grant No. RG93/16), and the National Natural Science Foundation of China (Grant No. 51575245). The TEM observation was performed at the Facility for Analysis, Characterization, Testing and Simulation (FACTS) in Nanyang Technological University, Singapore. 2021-06-09T07:53:57Z 2021-06-09T07:53:57Z 2019 Journal Article Li, R., Liu, Q., Tian, L., Wang, Y., Khor, K. A., Zhang, D. & Dong, Z. (2019). Discharge and densification in the spark plasma sintering of quasicrystal particles. Journal of Materials Science, 54(11), 8727-8742. https://dx.doi.org/10.1007/s10853-019-03489-6 0022-2461 0000-0003-1701-2297 0000-0003-2451-8528 0000-0002-9451-7355 0000-0001-6521-0445 0000-0003-1954-8423 0000-0003-2526-8954 0000-0001-8116-6747 https://hdl.handle.net/10356/151240 10.1007/s10853-019-03489-6 2-s2.0-85062655270 11 54 8727 8742 en RG93/16 Journal of Materials Science © 2019 Springer Science+Business Media, LLC, part of Springer Nature. All rights reserved. |
| spellingShingle | Engineering::Materials Electric-field Mechanisms Li, Ruitao Liu, Qing Tian, Lihui Wang, Yun Khor, Khiam Aik Zhang, Di Dong, Zhili Discharge and densification in the spark plasma sintering of quasicrystal particles |
| title | Discharge and densification in the spark plasma sintering of quasicrystal particles |
| title_full | Discharge and densification in the spark plasma sintering of quasicrystal particles |
| title_fullStr | Discharge and densification in the spark plasma sintering of quasicrystal particles |
| title_full_unstemmed | Discharge and densification in the spark plasma sintering of quasicrystal particles |
| title_short | Discharge and densification in the spark plasma sintering of quasicrystal particles |
| title_sort | discharge and densification in the spark plasma sintering of quasicrystal particles |
| topic | Engineering::Materials Electric-field Mechanisms |
| url | https://hdl.handle.net/10356/151240 |
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