Gas-Phase Reactions in Nano-Strand Formation from Al-Fe-Ni Powder Reacted with CaF<sub>2</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-MgO-MnO-TiO<sub>2</sub> Flux at 1350 °C: SEM Study and Diffusion Calculations
Fast high-temperature gas-phase reactions occurring in the limited space of the arc cavity in the submerged arc welding (SAW) process limit the study of specific gas-phase behaviours. A low-temperature experimental method is applied to investigate gas-phase reactions in the reaction of oxy-fluoride...
Saved in:
| Main Authors: | , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
|
| Series: | Reactions |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2624-781X/6/1/1 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850087985983258624 |
|---|---|
| author | Theresa Coetsee Frederik De Bruin |
| author_facet | Theresa Coetsee Frederik De Bruin |
| author_sort | Theresa Coetsee |
| collection | DOAJ |
| description | Fast high-temperature gas-phase reactions occurring in the limited space of the arc cavity in the submerged arc welding (SAW) process limit the study of specific gas-phase behaviours. A low-temperature experimental method is applied to investigate gas-phase reactions in the reaction of oxy-fluoride slag with Al-Fe-Ni metal powders. The presence of nano-strands in the slag cavities confirms the vaporisation and re-condensation of gasses. Ti is the main element in nano-strands, although some nano-strands also contain Al-Mg-Si-Na oxy-fluoride. Nano-strand end-caps contain Mn-Fe-Si fluoride, and some contain Ni. The Ni in nano-strand end-caps is sourced from the added Ni powder and indicates gas-phase transfer. The Ti in the nano-strands is sourced from the flux. Themochemistry calculations identify KAlF<sub>4</sub>, TiF<sub>3</sub>, NaAlF<sub>4</sub>, SiF<sub>4</sub>, AlF<sub>3</sub>, SiF<sub>3</sub>, and Na in the gas phase. Increased Al reaction results in decreased TiF<sub>3</sub> in the gas phase, likely due to the displacement of Ti from TiF<sub>3</sub>, resulting in the gas-phase transfer of Ti from the flux. Comparative diffusion flux calculations support Ti nano-strand formation via the vaporisation of TiF<sub>3</sub> and the re-condensation of Ti. The low-temperature simulation experiment applied here can be used to study the gas reaction behaviour in the reaction of oxy-fluoride flux with metal powders. |
| format | Article |
| id | doaj-art-70165fe03ef046d68ea2c00d69232137 |
| institution | DOAJ |
| issn | 2624-781X |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Reactions |
| spelling | doaj-art-70165fe03ef046d68ea2c00d692321372025-08-20T02:43:06ZengMDPI AGReactions2624-781X2025-01-0161110.3390/reactions6010001Gas-Phase Reactions in Nano-Strand Formation from Al-Fe-Ni Powder Reacted with CaF<sub>2</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-MgO-MnO-TiO<sub>2</sub> Flux at 1350 °C: SEM Study and Diffusion CalculationsTheresa Coetsee0Frederik De Bruin1Department of Materials Science and Metallurgical Engineering, University of Pretoria, Pretoria 0002, South AfricaDepartment of Materials Science and Metallurgical Engineering, University of Pretoria, Pretoria 0002, South AfricaFast high-temperature gas-phase reactions occurring in the limited space of the arc cavity in the submerged arc welding (SAW) process limit the study of specific gas-phase behaviours. A low-temperature experimental method is applied to investigate gas-phase reactions in the reaction of oxy-fluoride slag with Al-Fe-Ni metal powders. The presence of nano-strands in the slag cavities confirms the vaporisation and re-condensation of gasses. Ti is the main element in nano-strands, although some nano-strands also contain Al-Mg-Si-Na oxy-fluoride. Nano-strand end-caps contain Mn-Fe-Si fluoride, and some contain Ni. The Ni in nano-strand end-caps is sourced from the added Ni powder and indicates gas-phase transfer. The Ti in the nano-strands is sourced from the flux. Themochemistry calculations identify KAlF<sub>4</sub>, TiF<sub>3</sub>, NaAlF<sub>4</sub>, SiF<sub>4</sub>, AlF<sub>3</sub>, SiF<sub>3</sub>, and Na in the gas phase. Increased Al reaction results in decreased TiF<sub>3</sub> in the gas phase, likely due to the displacement of Ti from TiF<sub>3</sub>, resulting in the gas-phase transfer of Ti from the flux. Comparative diffusion flux calculations support Ti nano-strand formation via the vaporisation of TiF<sub>3</sub> and the re-condensation of Ti. The low-temperature simulation experiment applied here can be used to study the gas reaction behaviour in the reaction of oxy-fluoride flux with metal powders.https://www.mdpi.com/2624-781X/6/1/1oxy-fluoridenanodiffusionfluxweldingslag |
| spellingShingle | Theresa Coetsee Frederik De Bruin Gas-Phase Reactions in Nano-Strand Formation from Al-Fe-Ni Powder Reacted with CaF<sub>2</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-MgO-MnO-TiO<sub>2</sub> Flux at 1350 °C: SEM Study and Diffusion Calculations Reactions oxy-fluoride nano diffusion flux welding slag |
| title | Gas-Phase Reactions in Nano-Strand Formation from Al-Fe-Ni Powder Reacted with CaF<sub>2</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-MgO-MnO-TiO<sub>2</sub> Flux at 1350 °C: SEM Study and Diffusion Calculations |
| title_full | Gas-Phase Reactions in Nano-Strand Formation from Al-Fe-Ni Powder Reacted with CaF<sub>2</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-MgO-MnO-TiO<sub>2</sub> Flux at 1350 °C: SEM Study and Diffusion Calculations |
| title_fullStr | Gas-Phase Reactions in Nano-Strand Formation from Al-Fe-Ni Powder Reacted with CaF<sub>2</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-MgO-MnO-TiO<sub>2</sub> Flux at 1350 °C: SEM Study and Diffusion Calculations |
| title_full_unstemmed | Gas-Phase Reactions in Nano-Strand Formation from Al-Fe-Ni Powder Reacted with CaF<sub>2</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-MgO-MnO-TiO<sub>2</sub> Flux at 1350 °C: SEM Study and Diffusion Calculations |
| title_short | Gas-Phase Reactions in Nano-Strand Formation from Al-Fe-Ni Powder Reacted with CaF<sub>2</sub>-SiO<sub>2</sub>-Al<sub>2</sub>O<sub>3</sub>-MgO-MnO-TiO<sub>2</sub> Flux at 1350 °C: SEM Study and Diffusion Calculations |
| title_sort | gas phase reactions in nano strand formation from al fe ni powder reacted with caf sub 2 sub sio sub 2 sub al sub 2 sub o sub 3 sub mgo mno tio sub 2 sub flux at 1350 °c sem study and diffusion calculations |
| topic | oxy-fluoride nano diffusion flux welding slag |
| url | https://www.mdpi.com/2624-781X/6/1/1 |
| work_keys_str_mv | AT theresacoetsee gasphasereactionsinnanostrandformationfromalfenipowderreactedwithcafsub2subsiosub2subalsub2subosub3submgomnotiosub2subfluxat1350csemstudyanddiffusioncalculations AT frederikdebruin gasphasereactionsinnanostrandformationfromalfenipowderreactedwithcafsub2subsiosub2subalsub2subosub3submgomnotiosub2subfluxat1350csemstudyanddiffusioncalculations |