Lid\u00e9 porovn\u00e1vaj\u00ed zirkonov\u00e9 kuli\u010dky s kuli\u010dkami z oxidu hlinit\u00e9ho podle tvrdosti a doch\u00e1zej\u00ed k nespr\u00e1vn\u00e9mu z\u00e1v\u011bru. Oxid hlinit\u00fd je \u010dasto o n\u011bco tvrd\u0161\u00ed. To v\u0161ak nen\u00ed d\u016fvod, pro\u010d se ve vysokov\u00fdkonn\u00fdch ml\u00fdnech nakonec pou\u017e\u00edv\u00e1 zirkon, stabilizovan\u00fd oxidem yttriov\u00fdm nebo oxidem ceri\u010dit\u00fdm. D\u016fle\u017eit\u00fdmi parametry jsou hustota, hou\u017eevnatost a to, kolik z kuli\u010dky z\u016fstane neporu\u0161enou i po m\u011bs\u00edci provozu p\u0159i dan\u00e9 rychlosti.<\/p>\n
Kvalitn\u00ed kuli\u010dka z materi\u00e1lu Y-TZP se skl\u00e1d\u00e1 p\u0159ibli\u017en\u011b z 95% ZrO\u2082 a asi 5% Y\u2082O\u2083; jedn\u00e1 se o slinut\u00fd, hust\u00fd, jemnozrnn\u00fd materi\u00e1l s tetragon\u00e1ln\u00ed krystalovou m\u0159\u00ed\u017ekou. Hustota se pohybuje kolem 6,0 g\/cm\u00b3. U m\u00e9di\u00ed stabilizovan\u00fdch oxidem ceri\u010dit\u00fdm m\u016f\u017ee b\u00fdt hustota o n\u011bco vy\u0161\u0161\u00ed, kolem 6,2. U 92 % oxidu hlinit\u00e9ho se pohybuje kolem 3,6\u20133,7. Sklo m\u00e1 hustotu kolem 2,5. Kinetick\u00e1 energie p\u0159i sr\u00e1\u017ece je \u00fam\u011brn\u00e1 hmotnosti. P\u0159i stejn\u00e9m pr\u016fm\u011bru kuli\u010dek a stejn\u00e9 rychlosti p\u0159en\u00e1\u0161\u00ed n\u00e1raz kuli\u010dky ze zirkonu do suspenze v\u00edce energie. Takto lze dos\u00e1hnout jemn\u011bj\u0161\u00edho mlet\u00ed nebo mlet\u00ed se stejn\u00fdm v\u00fdt\u011b\u017ekem p\u0159i vy\u0161\u0161\u00edm obsahu pevn\u00fdch l\u00e1tek, ani\u017e by bylo nutn\u00e9 pouze zvy\u0161ovat ot\u00e1\u010dky ml\u00fdna, dokud se nevyho\u0159\u00ed jeho v\u00fdstelka.<\/p>\n
Lomov\u00e1 hou\u017eevnatost p\u0159edstavuje druhou polovinu. Oxid hlinit\u00fd je tvrd\u00fd a k\u0159ehk\u00fd. Lomov\u00e1 hou\u017eevnatost materi\u00e1l\u016f Y-TZP nebo Ce-TZP se obvykle pohybuje v rozmez\u00ed 8\u201312 MPa\u00b7m\u00bd, co\u017e je dvakr\u00e1t a\u017e t\u0159ikr\u00e1t v\u00edce ne\u017e u kuli\u010dky z oxidu hlinit\u00e9ho. Mechanismem je zpevn\u011bn\u00ed transformac\u00ed: kdy\u017e se trhlina sna\u017e\u00ed \u0161\u00ed\u0159it, tetragon\u00e1ln\u00ed zrno p\u0159ech\u00e1z\u00ed do monoklinick\u00e9 struktury a zm\u011bna objemu p\u016fsob\u00ed proti \u0161\u00ed\u0159en\u00ed trhliny. V ml\u00fdnu to znamen\u00e1 m\u00e9n\u011b rozdrcen\u00fdch kuli\u010dek na v\u00fdstupn\u00edm s\u00edtu a m\u00e9n\u011b ostr\u00fdch \u00falomk\u016f, kter\u00e9 opot\u0159ebov\u00e1vaj\u00ed rotor. Levn\u00fd zirkon s hrub\u00fdmi zrny nebo \u0161patnou stabilizac\u00ed tuto v\u00fdhodu nem\u00e1. Odlupuje se jako tvrd\u00e1 sk\u00e1la a vy pak plat\u00edte dvakr\u00e1t \u2013 za ztr\u00e1tu m\u00e9dia i za opot\u0159eben\u00ed ml\u00fdna.<\/p>\n
Pr\u00e1v\u011b p\u0159i opot\u0159eben\u00ed se projev\u00ed skute\u010dn\u00e1 hodnota po\u0159izovac\u00ed ceny. Zirkoni\u010ditan stoj\u00ed na kilogram n\u011bkolikr\u00e1t v\u00edce ne\u017e oxid hlinit\u00fd. V barv\u00e1ch, tisc\u00edch, elektronick\u00e9 keramice, materi\u00e1lech pro baterie a vysoce \u010dist\u00e9m k\u0159emenu je zne\u010di\u0161t\u011bn\u00ed zp\u016fsoben\u00e9 rychle se opot\u0159ebov\u00e1vaj\u00edc\u00ed kuli\u010dkou dra\u017e\u0161\u00ed ne\u017e samotn\u00e1 kuli\u010dka. Ocel zanech\u00e1v\u00e1 \u017eelezo. Oxid hlinit\u00fd zanech\u00e1v\u00e1 oxid hlinit\u00fd. Kuli\u010dka z materi\u00e1lu Y-TZP s n\u00edzk\u00fdm opot\u0159eben\u00edm zanech\u00e1v\u00e1 jen velmi m\u00e1lo ne\u010distot, co\u017e je rozhoduj\u00edc\u00ed v p\u0159\u00edpadech, kdy produkt nesm\u00ed p\u0159ij\u00edmat barviva ani \u017eelezo. M\u00e9dia stabilizovan\u00e1 oxidem ceri\u010dit\u00fdm jsou \u010dasto hlavn\u00edm pracovn\u00edm kon\u011bm ve vlhk\u00fdch, vysoce energetick\u00fdch ml\u00fdnech; t\u0159\u00eddy s obsahem oxidu yttrit\u00fdm jsou obvyklou volbou, kdy\u017e z\u00e1le\u017e\u00ed na \u010distot\u011b a mal\u00fdch velikostech (a\u017e 0,1\u20130,3 mm pro nanomlet\u00ed).<\/p>\n
Velikost mus\u00ed st\u00e1le odpov\u00eddat ml\u00fdnu. Kuli\u010dka o pr\u016fm\u011bru 2 mm v ml\u00fdnu ur\u010den\u00e9m pro 0,8 mm nebude \u201c\u00fadern\u011bji p\u016fsobit\u201d. Zp\u016fsob\u00ed zablokov\u00e1n\u00ed separ\u00e1toru a po\u0161kozen\u00ed s\u00edta. Rychlost pln\u011bn\u00ed, viskozita suspenze a obvodov\u00e1 rychlost rozhoduj\u00ed o tom, zda vysok\u00e1 hustota pom\u00e1h\u00e1, nebo jen generuje teplo. Korund zpevn\u011bn\u00fd zirkonem se nach\u00e1z\u00ed n\u011bkde uprost\u0159ed \u2013 je hust\u0161\u00ed a odoln\u011bj\u0161\u00ed ne\u017e \u010dist\u00fd korund, levn\u011bj\u0161\u00ed ne\u017e pln\u00fd TZP \u2013 a to je skute\u010dn\u00e1 kvalita, nikoli kompromisn\u00ed slogan, pokud mlet\u00ed nevy\u017eaduje hustotu 6 g\/cm\u00b3.<\/p>\n
Pokud m\u011bn\u00edte mlec\u00ed m\u00e9dium, neptejte se pouze na cenu za kilogram. Zeptejte se na m\u00edru opot\u0159eben\u00ed ve va\u0161\u00ed ka\u0161i, pevnost v tlaku p\u0159i pr\u016fm\u011bru, se kter\u00fdm pracujete, kulatost a na to, co se skute\u010dn\u011b z kuli\u010dky uvol\u0148uje do produktu. Zirkoniov\u00e1 kuli\u010dka je mlec\u00ed n\u00e1stroj. Vyplat\u00ed se, kdy\u017e ml\u00fdn spln\u00ed specifikace s men\u0161\u00ed ztr\u00e1tou mlec\u00edho m\u00e9dia a men\u0161\u00edm mno\u017estv\u00edm ne\u010distot v \u0161ar\u017ei. Nevyplat\u00ed se jen proto, \u017ee n\u00e1zev na pytli zn\u00ed pr\u00e9miov\u011b.<\/p>","protected":false},"excerpt":{"rendered":"
A Zirconia Ball Earns Its Keep in the Mill, Not on the Spec Sheet People compare zirconia balls to alumina by hardness and get the wrong answer. Alumina is often a bit harder. That is not why a high-energy mill ends up on yttria- or ceria-stabilized zirconia. The useful numbers are density, toughness, and how […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"ngg_post_thumbnail":0,"footnotes":""},"categories":[21],"tags":[],"class_list":{"0":"post-313","1":"post","2":"type-post","3":"status-publish","4":"format-standard","6":"category-knowledge","7":"czr-hentry"},"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/posts\/313"}],"collection":[{"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/comments?post=313"}],"version-history":[{"count":1,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/posts\/313\/revisions"}],"predecessor-version":[{"id":314,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/posts\/313\/revisions\/314"}],"wp:attachment":[{"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/media?parent=313"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/categories?post=313"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/zirconia-ceramics.com\/cs\/wp-json\/wp\/v2\/tags?post=313"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}