A microwave plasma process operating at atmospheric pressure was developed for the synthesis of SiC nanoparticles. The process utilizes methyltrichlorosilane (MTS) as precursor, acting as both carbon and silicon source, along with an additional hydrogen feed to ensure a fully reducing reaction environment. In addition, argon served as carrier gas. The parameters studied were the H 2 :MTS molar ratio and the total enthalpy, in the range 0-10 and 70-220 MJ/kg respectively. The particles size distribution ranged from 15 to 140 nm as determined by SEM and TEM micrographs. It was found that an increase in enthalpy and a higher H 2 :MTS ratio resulted in smaller SiC particle sizes. The adhesion of particles was a common occurrence during the process, resulting in larger agglomerate sizes.
Silicon carbide nanopowders were produced using a microwave-induced plasma process operating at 15 kPa absolute and at atmospheric pressure. Methyltrichlorosilane (MTS) served as precursor, due to its advantageous stoichiometric silicon-to-carbon ratio of unity, allowing it to act as both carbon and silicon source. Argon served as carrier gas, and an additional hydrogen feed helped ensure a fully reducing reaction environment. The parameters under investigation were the H 2 :MTS molar ratio and the total enthalpy. The particle size distribution ranged from 20 nm upwards, as determined by SEM and TEM micrographs. It was found that an increase in enthalpy and a higher H 2 :MTS ratio resulted in smaller SiC particle sizes. The adhesion of particles was a common occurrence during the process, resulting in larger agglomerate sizes. SiC layers were deposited at 15 kPa with thicknesses ranging from 5.8 to 15 μm.
Die sferoïdisering van metaalpoeier deur middel van plasmategnieke hou verskeie voordele in vir die gemak van beide materiaalbehandeling en itemvervaardiging. Hierdie voordele sluit onder meer in: meer vloeibaarheid, verhoogde poeierpakdigtheid, vermindering van interne holtes en breekvlakke, veranderinge in morfologie met laer wrywingskragte tussen partikels tot gevolg, sowel as minder kontaminering tydens pneumatiese vervoer, asook suiwerder partikels.Sferiese ysterpartikels is gedurende hierdie empiriese studie geproduseer met behulp van 'n mikrogolfplasma wat by atmosferiese druk bedryf is. Die reaktor bestaan uit 'n deursigtige kwartsbuis wat loodreg deur 'n reghoekige aluminiumgolfgeleier geplaas is, en die golfgeleier is op sy beurt aan 'n magnetron gekoppel wat verantwoordelik vir die opwekking van mikrogolwe is. Argongas vloei deur die kwartsbuis en word deur die mikrogolwe geïoniseer en tot die plasmatoestand opgewek. Die ysterpoeier word dan geleidelik tot die plasma ingevoer met behulp van 'n poeiervoerder wat bo-op die reaktor geposisioneer is. Die poeier word onder die plasmabol in die kwartsbuis met behulp van 'n zirkoniumwolfilter versamel. Die ysterpartikels is hierna gekarakteriseer met behulp van optiese mikroskopie, sowel as aftaselektronmikroskopie (SEM).Die resultate het die sferoïdisering van die ysterpoeiers bevestig, gepaard met 'n duidelike toename in die partikelgrootte. Partikelgroottes het van ongeveer 5 μm vergroot tot partikelgroottes van 20 μm tot 100 μm. Die SEM-foto's het ook 'n duidelike verandering in die morfologie aangedui, wat moontlik sinspeel op 'n onderliggende kristalvormingmeganisme. Die graad van sferoïdisering is relatief laag sodat 'n groot persentasie van die poeier nie sferoïdisering ondergaan het nie. Dit is waarskynlik vanweë die filamentagtige aard van die plasma; 'n eienskap wat by atmosferiese drukke voorkom en die totale volume van die plasma verlaag.Die interne morfologie van die partikels is ook bestudeer deur die poeiers in 'n organiese hars te suspendeer, gevolg deur 'n slyp-en poleerproses. Dié hars is toe onder die SEM bestudeer. Die interne morfologie van die produkpartikels het diverse resultate opgelewer, deurdat sommige partikels baie eenvormig was en ander weer groot defekte en holtes getoon het. Die variasie is moontlik 'n gevolg van die verskillende verhittingstye en vloeipaaie van die partikels deur die plasma. Gevolglik is die verhittingstye vergelyk met teoretiese modelle wat die grootte, smeltpunt en warmtekapasiteit van die partikel in ag neem. Die resultate het getoon dat die partikels genoeg tyd in die plasma deurbring sodat sferoïdisering volledig kan plaasvind. Die teenstrydige resultate word aan die genoemde filamentagtige aard van die plasma toegeskryf.Spheroidisation of iron powder in a microwave plasma reactor. Plasma-assisted spheroidisation of metal powders offers several advantages with respect to ease of material handling and item manufacturing. In this study, spherical iron particles were produced using a microwave plasma, and ...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.