\u00cd starfi m\u00ednu sem s\u00e9rfr\u00e6\u00f0ingur \u00ed hita\u00feolnum efnum me\u00f0 yfir 20 \u00e1ra reynslu hef \u00e9g s\u00e9\u00f0 margar n\u00fdjungar koma og fara. En k\u00edsilkarb\u00ed\u00f0 bundi\u00f0 me\u00f0 n\u00edtr\u00ed\u00f0i? \u00dea\u00f0 er eitt sem hefur haldi\u00f0 velli, og me\u00f0 g\u00f3\u00f0ri \u00e1st\u00e6\u00f0u. \u00deetta er efni\u00f0 sem \u00fe\u00fa velur \u00feegar hitastigi\u00f0 h\u00e6kkar, t\u00e6rslan gerir harkalega til s\u00edn og \u00fe\u00fa \u00fearft eitthva\u00f0 sem gefur sig ekki h\u00e1lfa lei\u00f0 \u00ed gegnum framlei\u00f0sluferli\u00f0. \u00deetta hita\u00feolna efni, oft skammta\u00f0 sem NBSiC e\u00f0a einfaldlega SiC nitride bonded, sameinar h\u00f6rku k\u00edsilkarb\u00ed\u00f0s og bindikraft k\u00edsiln\u00edtr\u00ed\u00f0s til a\u00f0 b\u00faa til v\u00f6ru sem er sterk, skilvirk og \u00f3tr\u00falega fj\u00f6lh\u00e6f. \u00de\u00f3 a\u00f0 \u00fea\u00f0 s\u00e9 ekki gl\u00e6silegasta lausnin sem v\u00f6l er \u00e1, \u00fe\u00e1 gerir frammista\u00f0a \u00feess \u00ed raunverulegum a\u00f0st\u00e6\u00f0um \u00fea\u00f0 a\u00f0 upp\u00e1haldi me\u00f0al verkfr\u00e6\u00f0inga \u00ed m\u00e1lmfr\u00e6\u00f0i, keram\u00edk og fleira. Sko\u00f0um n\u00e1nar hva\u00f0 gerir \u00fea\u00f0 svo gott \u2013 fr\u00e1 \u00fev\u00ed hvernig \u00fea\u00f0 er samsett til \u00feess hvar \u00fea\u00f0 skarar fram \u00far, og jafnvel \u00f3kostina sem vert er a\u00f0 hafa \u00ed huga. Ef \u00fe\u00fa ert a\u00f0 velja efni fyrir h\u00e1hitaa\u00f0ger\u00f0ir g\u00e6ti \u00feetta hj\u00e1lpa\u00f0 \u00fe\u00e9r a\u00f0 \u00e1kve\u00f0a hvort \u00feetta s\u00e9 r\u00e9tt val.<\/p>\n
<\/p>\n
Undirsta\u00f0a n\u00edtr\u00ed\u00f0bundins k\u00edsilkarb\u00ed\u00f0s liggur \u00ed hr\u00e1efnum \u00feess og snj\u00f6llri samsetningu \u00feeirra. Allt byrjar me\u00f0 k\u00edsilkarb\u00ed\u00f0kornum, sem framleidd eru me\u00f0 hinum klass\u00edska Acheson-ferli: hita bl\u00f6ndu k\u00edsilgler og kolefnis vi\u00f0 afar h\u00e1an hita, yfir 2000 \u00b0C, \u00ed rafbogagrafi. \u00deetta gefur \u00feau har\u00f0u, krist\u00f6llu\u00f0u SiC-agnir sem eru \u00feekktar fyrir endingu s\u00edna. Til a\u00f0 tengja \u00feau saman blanda framlei\u00f0endur s\u00edlikonmj\u00f6li vi\u00f0 og m\u00f3ta bl\u00f6nduna \u00ed form eins og kubba e\u00f0a r\u00f6r. S\u00ed\u00f0an kemur lykilstigi\u00f0 \u2013 brennsla \u00ed k\u00f6fnunarefnislofti vi\u00f0 1400\u20131500 \u00b0C. \u00dearna bregst k\u00edsill vi\u00f0 k\u00f6fnunarefni og myndar k\u00edsiln\u00edtr\u00ed\u00f0 (Si3N4), sem vex sem net f\u00ednna kristalla sem l\u00e6sa SiC-kornunum \u00e1 s\u00ednum sta\u00f0. Ni\u00f0ursta\u00f0an er samsett efni \u00fear sem SiC myndar 80% e\u00f0a meira af r\u00famm\u00e1linu, og n\u00edt\u00ed\u00f0inn virkar sem sterkur, sam\u00fe\u00e6ttandi bindiefni. Engin auka l\u00edm e\u00f0a leir eru nau\u00f0synleg, sem heldur efninu hreinu og tryggir fram\u00farskarandi eiginleika. Ef sko\u00f0u\u00f0 er \u00f6rbygging efnisins er h\u00fan heillandi: Si3N4 birtist sem langvaxnar h\u00e1r\u00e6\u00f0ar sem fl\u00e9ttast saman vi\u00f0 kubbalaga SiC-kristalla og mynda \u00feannig \u00fe\u00e9tta grind me\u00f0 st\u00fdr\u00f0ri porosity.<\/p>\n
Eiginleikar \u00feessara efna skara fram \u00far \u00e1 m\u00f6rgum lykilsvi\u00f0um. Varmafr\u00e6\u00f0ilega geta \u00feau \u00feola\u00f0 vinnsluhita allt a\u00f0 1650 \u00b0C vi\u00f0 oxunarskilyr\u00f0i og stundum h\u00e6rri vi\u00f0 afoxunarskilyr\u00f0i. Varnarfilmur \u00far k\u00edsli myndast \u00e1 yfirbor\u00f0inu vi\u00f0 \u00fatsetningu fyrir lofti og lokar \u00fev\u00ed fyrir frekari ni\u00f0urbroti. Hitaeinkennin skera sig einnig \u00far \u2013 yfirleitt 20 til 40 W\/m\u00b7K \u2013 sem hentar vel \u00ed notkun sem krefst jafns hitafl\u00e6\u00f0is, til d\u00e6mis \u00ed upphitunareiningum. Me\u00f0 hita\u00feenslu\u00fe\u00e6tti um 4,0 \u00d7 10\u207b\u2076 \u00b0C\u207b\u00b9 \u00feolir \u00fea\u00f0 \u00e1lagi\u00f0 af sn\u00f6ggum hita- og k\u00e6lumynstrum sem myndu brj\u00f3ta vi\u00f0kv\u00e6mari valkosti. \u00c1 v\u00e9lr\u00e6nu svi\u00f0i n\u00e1 \u00fer\u00fdstistyrkur oft yfir 200 MPa, og slitsterkja \u00feess er \u00ed fremstu r\u00f6\u00f0, \u00fe\u00f6kk s\u00e9 h\u00f6rku SiC sem er n\u00e1nast jafn h\u00f6r\u00f0 og demantur. \u00c9g hef framkv\u00e6mt pr\u00f3fanir \u00fear sem s\u00fdni \u00feoldu hermdar slaggfl\u00e6\u00f0i sem hef\u00f0u slitna\u00f0 alum\u00edn\u00f3xtein \u00ed helmingi t\u00edma.<\/p>\n
S\u00ed\u00f0an er efnafr\u00e6\u00f0ileg seigla. Nitr\u00ed\u00f0bundi\u00f0 SiC \u00feolir fj\u00f6lbreytt \u00e1reiti \u2013 s\u00fdrur, basa, br\u00e1\u00f0m\u00e1lma og salta. Vi\u00f0 \u00e1lbr\u00e6\u00f0slu, til d\u00e6mis, ver \u00fea\u00f0 sig gegn fl\u00fa\u00f3r\u00ed\u00f0\u00e1r\u00e1sum sem ey\u00f0ileggja \u00f6nnur hita\u00feoln efni. Efnismassi \u00feess er \u00e1 bilinu 2,7 til 3,1 g\/cm\u00b3, sem gerir \u00fea\u00f0 l\u00e9ttara en m\u00f6rg \u00fe\u00e9tt keramik, og au\u00f0veldar uppsetningu \u00ed st\u00f3rum mannvirkjum. Hollir eru yfirleitt 10\u201320%, sem leyfir loftfl\u00e6\u00f0i \u00e1n \u00feess a\u00f0 veikja heildina. En vert er a\u00f0 taka fram a\u00f0 \u00ed r\u00f6kum, h\u00e1hitaumhverfi yfir 1400 \u00b0C g\u00e6ti n\u00edtr\u00ed\u00f0fasi\u00f0 hydrolyserast, sem lei\u00f0ir til ni\u00f0urbrots. Umhverfis\u00fe\u00e6ttir skipta \u00fev\u00ed miklu m\u00e1li fyrir endingu \u00feess.<\/p>\n
\u00deegar kemur a\u00f0 notkun skarar n\u00edtr\u00ed\u00f0bundi\u00f0 SiC fram \u00far \u00ed umhverfi \u00fear sem bilun er ekki valkostur. \u00cd st\u00e1lframlei\u00f0slu er \u00fea\u00f0 \u00f3missandi \u00ed kl\u00e6\u00f0ningu bl\u00e1stursofna, einkum \u00ed ne\u00f0ri hluta rennslisholunnar og \u00ed helluz\u00f3num sem ver\u00f0a fyrir miklum hita og v\u00e9lr\u00e6num \u00e1reiti. \u00c9g veitti einu sinni r\u00e1\u00f0gj\u00f6f um endurkl\u00e6\u00f0ningu \u00fear sem notkun SiC framlengdi framlei\u00f0slulotu \u00far \u00e1tta m\u00e1nu\u00f0um \u00ed yfir tv\u00f6 \u00e1r og dr\u00f3 verulega \u00far kostna\u00f0i. Fyrir \u00f3j\u00e1rnmetallar eins og kopar og sink er \u00fea\u00f0 nota\u00f0 \u00ed krosspottum, sp\u00fattum og lei\u00f0slum; yfirbor\u00f0i\u00f0 blotnar ekki au\u00f0veldlega, svo m\u00e1lmur festist ekki og valdi ekki st\u00edflum. \u00cd keram\u00edksm\u00ed\u00f0i \u00fej\u00f3nar \u00fea\u00f0 sem ofnpl\u00f6tur og stu\u00f0ningur, \u00feolir endurteknar brennur \u00e1n \u00feess a\u00f0 bogna.<\/p>\n
Fyrir utan hef\u00f0bundna framlei\u00f0slu finnur \u00fe\u00fa \u00fea\u00f0 \u00ed \u00fargangs-til-orkuverksmi\u00f0jum sem kl\u00e6\u00f0a ofna gegn t\u00e6randi gufum, e\u00f0a \u00ed efnafr\u00e6\u00f0ivinnslu fyrir \u00edl\u00e1t sem me\u00f0h\u00f6ndla vi\u00f0brag\u00f0sefni. Undanfari\u00f0 hefur \u00fea\u00f0 birst \u00ed h\u00e1\u00fer\u00f3u\u00f0um orkukerfum, eins og \u00ed syngas-hvarfak\u00fatum e\u00f0a s\u00f3lars\u00f6fnurum. Formger\u00f0in er sveigjanleg \u2013 \u00fer\u00fdst \u00ed venjulegar m\u00farsteina e\u00f0a s\u00e9rsni\u00f0in form, me\u00f0 v\u00ed\u00f0fe\u00f0mum m\u00e1lum. Vi\u00f0 uppsetningu skal para \u00fea\u00f0 me\u00f0 m\u00far sem hentar SiC til a\u00f0 n\u00e1 sem bestum \u00e1rangri. Kostna\u00f0ur? \u00dea\u00f0 er d\u00fdrara en hef\u00f0bundnir eldm\u00farsteinar, kannski $5\u201310 \u00e1 k\u00edl\u00f3gramm, en \u00e1 mj\u00f6g slitnum sv\u00e6\u00f0um borgar \u00fea\u00f0 sig flj\u00f3tt me\u00f0 minni vi\u00f0haldi.<\/p>\n
Au\u00f0vita\u00f0, eins og hva\u00f0a efni sem er, hefur \u00fea\u00f0 takm\u00f6rk. Framlei\u00f0sluferli\u00f0 krefst n\u00e1kv\u00e6mni; ef n\u00edtreringin er ekki fullger\u00f0 g\u00e6tir\u00f0u enda\u00f0 me\u00f0 veikbur\u00f0a sv\u00e6\u00f0i sem eru vi\u00f0kv\u00e6m fyrir bilun. Me\u00f0h\u00f6ndlun og v\u00e9lr\u00e6n vinnsla mynda ryk sem er heilsuh\u00e6ttulegt\u2014m\u00f6gulega krabbameinsvaldandi\u2014\u00fev\u00ed krefst alltaf vi\u00f0eigandi ryksstj\u00f3rnunar og verndarb\u00fana\u00f0ar. Fr\u00e1 umhverfissj\u00f3narmi\u00f0i krefst framlei\u00f0slan mikla orku, en framfarir \u00ed endurvinnslu hj\u00e1lpa: sum fyrirt\u00e6ki endurheimta 60\u201370% af SiC \u00far g\u00f6mlum f\u00f3\u00f0ringum. Framt\u00ed\u00f0ar\u00fer\u00f3un felur \u00ed s\u00e9r har\u00f0ari afbrig\u00f0i me\u00f0 b\u00e6ttum trefjum til a\u00f0 auka vi\u00f0n\u00e1msgetu gegn sprungum, e\u00f0a jafnvel 3D-prenta\u00f0ar \u00edhluti til a\u00f0 l\u00e1gmarka \u00fargang.<\/p>\n
Til a\u00f0 draga saman, k\u00edsilkarb\u00ed\u00f0 me\u00f0 n\u00edtr\u00ed\u00f0bindingu er ekki bara enn eitt hita\u00feoli\u00f0 efni \u2013 \u00fea\u00f0 er sanna\u00f0ur bandama\u00f0ur til a\u00f0 takast \u00e1 vi\u00f0 erfi\u00f0ustu varmar- og efna\u00e1skoranir. \u00dar reynslu minni \u00e1 \u00feessu svi\u00f0i er \u00fea\u00f0 vali\u00f0 sem oft breytir ja\u00f0arsamr\u00e6mum \u00ed skilvirka starfsemi, eins og \u00ed \u00e1lverinu \u00fear sem \u00fea\u00f0 tv\u00f6falda\u00f0i l\u00edft\u00edma krosspottanna. Ef \u00fe\u00fa ert a\u00f0 \u00edhuga \u00fea\u00f0, met\u00f0u a\u00f0st\u00e6\u00f0ur \u00fe\u00ednar vandlega \u2013 hitastigssvi\u00f0, efna\u00fatsetningu, v\u00e9lr\u00e6na spennu \u2013 og sko\u00f0a\u00f0u vi\u00f0eigandi sta\u00f0la eins og ASTM C863. Haf\u00f0u samband vi\u00f0 vi\u00f0urkennda framlei\u00f0endur eins og Saint-Gobain e\u00f0a ESK Ceramics til a\u00f0 f\u00e1 n\u00e1nari uppl\u00fdsingar. \u00cd n\u00fat\u00edma\u00e1taki fyrir sj\u00e1lfb\u00e6ra i\u00f0na\u00f0 eru efni eins og \u00feetta lykilatri\u00f0i, sem sameina \u00e1rei\u00f0anleika og m\u00f6guleika \u00e1 enn frekari framf\u00f6rum.<\/p>","protected":false},"excerpt":{"rendered":"
Nitride Bonded Silicon Carbide: A Stalwart in the Face of Industrial Extremes In my line of work as a refractory materials expert with over 20 years under my belt, I’ve seen a lot of innovations come and go. But nitride bonded silicon carbide? That’s one that has stuck around, and for good reason. It’s the […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-49","post","type-post","status-publish","format-standard","hentry","category-news"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/posts\/49","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/comments?post=49"}],"version-history":[{"count":3,"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/posts\/49\/revisions"}],"predecessor-version":[{"id":52,"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/posts\/49\/revisions\/52"}],"wp:attachment":[{"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/media?parent=49"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/categories?post=49"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/nitridebondedsic.com\/is\/wp-json\/wp\/v2\/tags?post=49"}],"curies":[{"name":"vp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}