Ahoj Jacku, kopu do sebe v Los Angeles, kde je mo\u017en\u00e1 nejv\u011bt\u0161\u00edm snem dal\u0161\u00ed filmov\u00fd trh\u00e1k, ale tady, v drsn\u00e9m sv\u011bt\u011b materi\u00e1lov\u00e9ho in\u017een\u00fdrstv\u00ed, jsou skute\u010dn\u00fdmi hv\u011bzdami trubky z karbidu k\u0159em\u00edku. S keramikou se pot\u00fdk\u00e1m u\u017e 42 let - za\u010d\u00ednal jsem v ocel\u00e1rn\u011b v Pittsburghu, pron\u00e1sledoval no\u010dn\u00ed m\u016fry z koroze v chemi\u010dk\u00e1ch dole v Houstonu a te\u010f rad\u00edm se v\u0161\u00edm od jadern\u00fdch za\u0159\u00edzen\u00ed po sol\u00e1rn\u00ed farmy. SiC trubky? Jsou to odoln\u00e9 trubky, kter\u00e9 se objev\u00ed, kdy\u017e se v\u0161echno ostatn\u00ed roztav\u00ed, poprask\u00e1 nebo rozpadne. Vid\u011bl jsem, jak se z proces\u016f n\u00e1chyln\u00fdch k hav\u00e1ri\u00edm st\u00e1v\u00e1 spolehliv\u00fd hodinov\u00fd strojek. V tomto \u010dl\u00e1nku v\u00e1m je vylo\u017e\u00edm v hrub\u00fdch rysech: co jsou za\u010d, jak se kuj\u00ed, kde dominuj\u00ed a jak\u00e9 jsem se nau\u010dil tvrd\u00e9 postupy. Budeme m\u00edt kolem 800 slov, \u017e\u00e1dn\u00e9 kecy, prost\u011b jen \u0159e\u010di z d\u00edlny.<\/p>\n
<\/p>\n
Ud\u011blejme si z\u00e1kladn\u00ed p\u0159edstavu. Karbid k\u0159em\u00edku je syntetick\u00e1 keramika, kter\u00e1 vznik\u00e1 taven\u00edm k\u0159em\u00edku a uhl\u00edku za vysok\u00fdch teplot. U trubek mluv\u00edme o vysoce \u010dist\u00fdch formulac\u00edch - alfa nebo beta krystalech SiC hust\u011b zabalen\u00fdch jako diamant. Tyto dut\u00e9 v\u00e1lce se pohybuj\u00ed od tenk\u00fdch 5mm ID pro laboratorn\u00ed sondy a\u017e po mohutn\u00e9 250mm monstra pro pr\u016fmyslov\u00e9 kan\u00e1ly, jejich\u017e d\u00e9lka dosahuje 4 metr\u016f a v\u00edce. Hustota se pohybuje mezi 3,1-3,2 g\/cm\u00b3, jsou leh\u010d\u00ed ne\u017e ocel, ale jejich tepeln\u00e1 vodivost (100-150 W\/m-K) odv\u00e1d\u00ed teplo jako profesion\u00e1l. Dr\u017e\u00ed tvar a\u017e do teploty sublimace 2 700 \u00b0C, bojuj\u00ed s oxidac\u00ed a\u017e do 1 600 \u00b0C a vysm\u00edvaj\u00ed se kyselin\u00e1m, louh\u016fm a roztaven\u00fdm kov\u016fm. Tvrdost? 9,5 Mohsovy stupnice - nejv\u011bt\u0161\u00ed nep\u0159\u00edtel od\u011bru. J\u00e1 jsem se s nimi sezn\u00e1mil v roce 85 na zply\u0148ova\u010di uhl\u00ed: ze slitinov\u00fdch trubek byl za p\u00e1r m\u011bs\u00edc\u016f \u0161v\u00fdcarsk\u00fd s\u00fdr, SiC trubky fungovaly t\u0159i roky v kuse.<\/p>\n
Kov\u00e1n\u00ed trubek SiC je jako v\u00fdroba me\u010de v pekeln\u00e9m ohni. Surov\u00fd SiC pr\u00e1\u0161ek poch\u00e1z\u00ed z Achesonova procesu - k\u0159emi\u010dit\u00e9ho p\u00edsku a koksu, kter\u00fd se zap\u00e1l\u00ed p\u0159i teplot\u011b 2 400 \u00b0C v elektrick\u00fdch pec\u00edch. P\u0159im\u00edch\u00e1me pojiva, zelenou trubku vytla\u010d\u00edme nebo izostaticky slisujeme a pot\u00e9 ji slinujeme v pec\u00edch na inertn\u00ed plyn p\u0159i teplot\u011b 2 000-2 300 \u00b0C. \u017d\u00e1dn\u00e1 tavenina - pouze dif\u00fazn\u00ed spojen\u00ed, kter\u00e9 vytv\u00e1\u0159\u00ed monolitickou strukturu. U reak\u010dn\u011b v\u00e1zan\u00fdch druh\u016f (levn\u011bj\u0161\u00edch, ale s ur\u010dit\u00fdm mno\u017estv\u00edm voln\u00e9ho k\u0159em\u00edku) se p\u0159edlisek z uhl\u00edku napou\u0161t\u00ed k\u0159em\u00edkem. Potil jsem se v za\u0159\u00edzen\u00edch od Tennessee po Tchaj-wan, kde se pomoc\u00ed CVD (chemick\u00e9 napa\u0159ov\u00e1n\u00ed) p\u0159id\u00e1vaj\u00ed ultra\u010dist\u00e9 povlaky pro \u010distotu polovodi\u010d\u016f. Po sp\u00e9k\u00e1n\u00ed se diamantov\u00fdmi n\u00e1stroji brous\u00ed ID s mikronovou toleranc\u00ed - 0,02 mm rovnost nebo \u0161patn\u011b. K\u0159ehk\u00fd vn\u011bj\u0161\u00ed povrch chr\u00e1n\u00ed pl\u00e1\u0161t\u011b z nerezov\u00e9 oceli nebo kompozit\u016f.<\/p>\n
Typy se li\u0161\u00ed jako n\u00e1\u0159ad\u00ed v automechanick\u00e9 krabici. Slinut\u00e9 trubice alfa-SiC jsou hutn\u00fdmi kr\u00e1li pro \u010dist\u00e9, vysokotlak\u00e9 koncerty. Nitridem pojen\u00e9 (NSiC) p\u0159id\u00e1vaj\u00ed nitrid k\u0159em\u00edku pro odolnost proti n\u00e1raz\u016fm, ide\u00e1ln\u00ed ve sl\u00e9v\u00e1rn\u00e1ch. Trubky s oxidovou vazbou (OSiC) sni\u017euj\u00ed n\u00e1klady na pr\u00e1ci p\u0159i st\u0159edn\u00edch teplot\u00e1ch. Rekrystalizovan\u00e9 (RSiC) p\u0159in\u00e1\u0161ej\u00ed p\u00f3rovitost pro filtry nebo dif\u00fazi plyn\u016f. Uzav\u0159en\u00e9 pl\u00e1\u0161t\u011b termo\u010dl\u00e1nk\u016f, s\u00e1lav\u00e9 oh\u0159\u00edva\u010de se \u0161roubovit\u00fdmi dr\u00e1\u017ekami nebo \u017eebrovan\u00e9 v\u00fdm\u011bn\u00edky tepla - na m\u00edru. P\u0159i rekonstrukci pece, kterou jsem vedl pro skl\u00e1rnu v Ohiu, jsme pou\u017eili p\u0159\u00edrubov\u00e9 trubky NSiC; zvl\u00e1dly bez probl\u00e9m\u016f v\u00fdkyvy o 1400 \u00b0C.<\/p>\n
Kde ho drt\u00ed? V peklech s vysokou teplotou. V petrochemick\u00e9m pr\u016fmyslu si trubky SiC vym\u011b\u0148uj\u00ed teplo v krakov\u00e1n\u00ed kyseliny s\u00edrov\u00e9 nebo v ethylenov\u00fdch pec\u00edch a p\u0159ekon\u00e1vaj\u00ed Incoloy 5x. Metalurgie je miluje jako ponorn\u00e9 oh\u0159\u00edva\u010de v hlin\u00edkov\u00fdch tavb\u00e1ch - \u017e\u00e1dn\u00e9 zne\u010di\u0161t\u011bn\u00ed struskou. Elektr\u00e1rny je pou\u017e\u00edvaj\u00ed v kotl\u00edch pro p\u0159eh\u0159\u00e1tou p\u00e1ru. Polovodi\u010dov\u00e9 tov\u00e1rny: difuzn\u00ed trubice pro dopov\u00e1n\u00ed desti\u010dek p\u0159i 1 200 \u00b0C, nulov\u00e9 ne\u010distoty. Sol\u00e1rn\u00ed energie: p\u0159ij\u00edmac\u00ed trubice v CSP v\u011b\u017e\u00edch nas\u00e1kl\u00e9 proudem o teplot\u011b 1 000 \u00b0C. Dokonce i potravin\u00e1\u0159sk\u00e9 pece - sterilizace, kde je hygiena na prvn\u00edm m\u00edst\u011b. Vrchol z m\u00e9ho \u017eivotopisu: z\u00e1vod na zpracov\u00e1n\u00ed jadern\u00e9ho paliva v Idahu. Trubky ze slitiny selhaly kv\u016fli radiaci a halogenid\u016fm; SiC vydr\u017eel deset let a v\u00fdrazn\u011b sn\u00ed\u017eil radia\u010dn\u00ed odpad.<\/p>\n
V\u00fdhoda oproti soupe\u0159\u016fm? P\u0159i teplot\u011b nad 1000 \u00b0C kovy podl\u00e9haj\u00ed korozi, SiC se da\u0159\u00ed. Hlin\u00edk je levn\u00fd, ale k\u0159ehk\u00fd p\u0159i n\u00e1razech; zirkonium se rozpad\u00e1. N\u00edzk\u00e1 rozta\u017enost SiC (4 x 10^-6\/K) znamen\u00e1, \u017ee nedoch\u00e1z\u00ed k tepeln\u00e9 \u00fanav\u011b. Polovi\u010dn\u00ed hmotnost oceli usnad\u0148uje instalaci a recyklovatelnost odpov\u00edd\u00e1 ekologick\u00fdm p\u0159edpis\u016fm. Jist\u011b, k\u0159ehk\u00fd - K1c kolem 4 MPa-m^{1\/2} - tak\u017ee \u017e\u00e1dn\u00e1 kladiva. Cena: $200-2 000 za trubku, ale n\u00e1vratnost v m\u011bs\u00edc\u00edch d\u00edky provozuschopnosti. P\u0159i konzultac\u00edch v cement\u00e1\u0159sk\u00e9 peci se SiC vyplatil za \u010dty\u0159i m\u011bs\u00edce jen d\u00edky \u00faspo\u0159e paliva.<\/p>\n
Spr\u00e1vn\u00fd v\u00fdb\u011br: Maxim\u00e1ln\u00ed teplota, atmosf\u00e9ra (oxidace vy\u017eaduje n\u00e1t\u011bry), pr\u016ftoky. Pro vakuum - hust\u011b slinut\u00e9; pro abraziva - siln\u011bj\u0161\u00ed st\u011bny. Obra\u0165te se na Saint-Gobain nebo Morgan, aby v\u00e1m poskytli certifik\u00e1ty - ASTM C1674 nebo n\u011bco podobn\u00e9ho. Zku\u0161ebn\u00ed vzorky: tepeln\u00fd cyklus v peci. Instalujte opatrn\u011b - gumov\u00e9 dr\u017e\u00e1ky pohlcuj\u00ed vibrace, p\u0159\u00edruby utahujte jemn\u011b. \u00dadr\u017eba? \u010ctvrtletn\u00ed kontrola prasklin ultrazvukem; \u010di\u0161t\u011bn\u00ed m\u011bkk\u00fdmi kart\u00e1\u010dky, bez abraziv. Skladujte v suchu a na rovin\u011b - vlhkost je tich\u00fd zabij\u00e1k.<\/p>\n
Budoucnost je hork\u00e1. 3D tisk SiC s p\u0159izp\u016fsobenou p\u00f3rovitost\u00ed pro katalytick\u00e9 reaktory. Nanokompozity s p\u0159\u00edm\u011bs\u00ed grafenu pro zv\u00fd\u0161en\u00ed vodivosti v bateri\u00edch pro elektromobily. Biouhl\u00edkov\u00e9 zdroje sni\u017euj\u00ed ekologickou stopu. Vod\u00edkov\u00e1 ekonomika? SiC trubky v reformerech za\u017eij\u00ed boom, zvl\u00e1dnou \u010dist\u00fd H2 o teplot\u011b 900 \u00b0C bez k\u0159ehnut\u00ed.<\/p>\n
Zabalte to, Jacku: Trubky z karbidu k\u0159em\u00edku nejsou ok\u00e1zal\u00e9 - jsou tich\u00fdmi str\u00e1\u017eci, kte\u0159\u00ed chr\u00e1n\u00ed pr\u016fmysl p\u0159ed krachem. D\u00edky nim se moje projekty, kter\u00e9 jsem neprovedl, zm\u011bnily na zelen\u00e9 sv\u011btlo a u\u0161et\u0159ily miliony. Pokud \u010del\u00edte extr\u00e9mn\u00edm podm\u00ednk\u00e1m v technologick\u00fdch centrech Los Angeles nebo jinde, jsou tyto trubky va\u0161\u00edm esem. P\u0159ekonaj\u00ed humbuk a dodaj\u00ed zbo\u017e\u00ed. Pot\u0159ebujete poradit s nastaven\u00edm? Nechte si poradit s detaily - m\u00e1m jizvy i z hor\u0161\u00edch situac\u00ed.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon Carbide Tube: The Indestructible Pipes That Conquer Heat, Corrosion, and Industrial Mayhem Hey Jack, kicking back in LA where the biggest pipe dream might be the next blockbuster script, but over here in the gritty world of materials engineering, silicon carbide tube are the real stars. I’ve been wrestling with ceramics for 42 years […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2],"tags":[],"class_list":["post-42","post","type-post","status-publish","format-standard","hentry","category-news"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/posts\/42","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/comments?post=42"}],"version-history":[{"count":2,"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/posts\/42\/revisions"}],"predecessor-version":[{"id":44,"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/posts\/42\/revisions\/44"}],"wp:attachment":[{"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/media?parent=42"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/categories?post=42"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/lobadesignco.com\/cs\/wp-json\/wp\/v2\/tags?post=42"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}