[{"@context":"https:\/\/schema.org\/","@type":"Article","@id":"https:\/\/www.dokr.cz\/co-je-to-korund\/#Article","mainEntityOfPage":"https:\/\/www.dokr.cz\/co-je-to-korund\/","headline":"Co je to korund","name":"Co je to korund","description":"N\u011bkte\u0159\u00ed z v\u00e1s, zejm\u00e9na stroja\u0159i, si mo\u017en\u00e1 vybav\u00ed u\u010divo ze st\u0159edn\u00edch \u0161kol, kdy byli \u017e\u00e1ci a studenti podrobov\u00e1ni zkou\u0161en\u00ed z tvrdosti nerost\u016f. Ta se m\u011b\u0159\u00ed […]","datePublished":"2023-05-03","dateModified":"2023-07-03","author":{"@type":"Person","@id":"https:\/\/www.dokr.cz\/author\/#Person","name":"","url":"https:\/\/www.dokr.cz\/author\/","identifier":1,"image":{"@type":"ImageObject","@id":"https:\/\/secure.gravatar.com\/avatar\/0c4621640b5c0734669aeb181ef77969b528487727344f28e734a206566ea0f1?s=96&d=mm&r=g","url":"https:\/\/secure.gravatar.com\/avatar\/0c4621640b5c0734669aeb181ef77969b528487727344f28e734a206566ea0f1?s=96&d=mm&r=g","height":96,"width":96}},"publisher":{"@type":"Organization","name":"dokr.cz","logo":{"@type":"ImageObject","@id":"\/logo.png","url":"\/logo.png","width":600,"height":60}},"image":{"@type":"ImageObject","@id":"https:\/\/www.dokr.cz\/wp-content\/uploads\/ship-16954_640.jpg","url":"https:\/\/www.dokr.cz\/wp-content\/uploads\/ship-16954_640.jpg","height":0,"width":0},"url":"https:\/\/www.dokr.cz\/co-je-to-korund\/","about":["V\u00fdrobky"],"wordCount":396,"articleBody":"   N\u011bkte\u0159\u00ed z v\u00e1s, zejm\u00e9na stroja\u0159i, si mo\u017en\u00e1 vybav\u00ed u\u010divo ze st\u0159edn\u00edch \u0161kol, kdy byli \u017e\u00e1ci a studenti podrobov\u00e1ni zkou\u0161en\u00ed z tvrdosti nerost\u016f. Ta se m\u011b\u0159\u00ed dle stupnice od jedn\u00e9 do dev\u00edti, p\u0159i\u010dem\u017e dev\u00edtka je nejvy\u0161\u0161\u00ed hodnotou tvrdosti. Dosahuje j\u00ed pouze diamant a korund. Uv\u00e1d\u00ed se, \u017ee diamant je nejtvrd\u0161\u00ed nerost na sv\u011bt\u011b, jde o uhl\u00edk v krychlov\u00e9 m\u0159\u00ed\u017ece, kter\u00fd vlivem obrovsk\u00e9ho tlaku ve velk\u00fdch zemsk\u00fdch hloubk\u00e1ch musel nat\u011bsnat atomy v m\u0159\u00ed\u017ece z p\u016fvodn\u00edho \u0161estere\u010dn\u00e9ho tvaru do krychlov\u00e9ho.V podobn\u00e9m duchu se odv\u00edj\u00ed i p\u0159\u00edb\u011bh korundu, jedn\u00e1 se o oxid hlinit\u00fd, jeho\u017e krystalick\u00e1 struktura je natolik pevn\u00e1, \u017ee odol\u00e1v\u00e1 i t\u011bm nejtvrd\u0161\u00edm kov\u016fm. Z tohoto d\u016fvodu se tak\u00e9 vyu\u017e\u00edv\u00e1 pro obr\u00e1b\u011bn\u00ed a je velmi obl\u00edben\u00fdm zdrojem – m\u00e9diem pro tzv. p\u00edskov\u00e1n\u00ed. P\u00edskov\u00e1n\u00ed je proces, kdy se pod velk\u00fdm tlakem vh\u00e1n\u00ed z trysky abrazivn\u00ed materi\u00e1l, a ten odstra\u0148uje z povrchu obrobku ne\u017e\u00e1douc\u00ed l\u00e1tky. V\u011bt\u0161inou jde o korozi a zbytky barev, r\u016fzn\u00e9 chemik\u00e1lie, mastnotu a \u0161m\u00edr, zeminu, prach apod. Podle druhu abrazivn\u00edho materi\u00e1lu se tak\u00e9 m\u011bn\u00ed samotn\u00fd proces \u2013 struktura p\u00edskov\u00e1n\u00ed na operace prvotn\u00ed, kter\u00e9 odstran\u00ed v\u011bt\u0161inu hrub\u00fdch ne\u010distot, a na operace fin\u00e1ln\u00ed pro dosa\u017een\u00ed povrchu jemn\u00e9ho a hladk\u00e9ho.Zvl\u00e1\u0161tn\u00ed postaven\u00ed zast\u00e1v\u00e1 pr\u00e1v\u011b korund. Jeliko\u017e se jedn\u00e1 o relativn\u011b levn\u00fd zdroj velmi tvrd\u00e9ho materi\u00e1lu (rozhodn\u011b mnohem levn\u011bj\u0161\u00ed, ne\u017e kdybyste p\u00edskovali kov diamanty), m\u00e1te mo\u017enost jeho prost\u0159ednictv\u00edm zajistit odstran\u011bn\u00ed i t\u011bch nejodoln\u011bj\u0161\u00edch ne\u010distot. Abrazivo korund lze vyu\u017e\u00edt v metalurgii kov\u016f, ve stroj\u00edrenstv\u00ed, v \u00fadr\u017eb\u011b, ale i pro \u00fa\u010dely kutilstv\u00ed a u milovn\u00edk\u016f staro\u017eitnost\u00ed, automobilov\u00fdch veter\u00e1n\u016f, technick\u00fdch staveb \u010di stroj\u016f atd.Jestli\u017ee tedy vyu\u017eijete korund jako abrazivo, m\u016f\u017ee se v\u00e1m pak hodit i materi\u00e1l mnohem k\u0159eh\u010d\u00ed, vyu\u017eiteln\u00fd pro fin\u00e1ln\u00ed za\u010di\u0161\u0165ovac\u00ed pr\u00e1ce, jako je nap\u0159\u00edklad balotina \u2013 velmi drobn\u00e9 sklen\u011bn\u00e9 kuli\u010dky, s nimi\u017e doc\u00edl\u00edte velmi hladk\u00e9ho a \u010dist\u00e9ho povrchu.                                                                                                                                                                                                                                                                                                                                                                                          4.3\/5 - (6 votes)        "},{"@context":"https:\/\/schema.org\/","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Co je to korund","item":"https:\/\/www.dokr.cz\/co-je-to-korund\/#breadcrumbitem"}]}]