{"id":63456,"date":"2022-06-09T02:52:44","date_gmt":"2022-06-09T07:52:44","guid":{"rendered":"https:\/\/www.bjultrasonic.com\/piezo-ceramics-the-definition-of-tensile-strength\/"},"modified":"2025-01-27T06:14:55","modified_gmt":"2025-01-27T11:14:55","slug":"piezo-ceramics-the-definition-of-tensile-strength","status":"publish","type":"post","link":"https:\/\/www.bjultrasonic.com\/cs\/piezo-ceramics-the-definition-of-tensile-strength\/","title":{"rendered":"Piezokeradika: Definice a pevnost v tahu"},"content":{"rendered":"<p>Piezokeraick\u00e9 materi\u00e1ly nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech, od senzor\u016f a aktu\u00e1tor\u016f a\u017e po gener\u00e1tory ultrazvuku.  Jedn\u00edm z kl\u00ed\u010dov\u00fdch parametr\u016f, kter\u00e9 ur\u010duj\u00ed jejich vlastnosti a pou\u017eitelnost, je tahov\u00e1 pevnost.  Pochopen\u00ed tohoto parametru je z\u00e1sadn\u00ed pro spr\u00e1vn\u00fd n\u00e1vrh a aplikaci piezokeraick\u00fdch sou\u010d\u00e1stek.  Tento \u010dl\u00e1nek se podrobn\u011bji zab\u00fdv\u00e1 definic\u00ed a v\u00fdznamem tahov\u00e9 pevnosti piezokeraick\u00fdch materi\u00e1l\u016f.<\/p>\n<p>Definice tahov\u00e9 pevnosti piezokeraick\u00fdch materi\u00e1l\u016f<\/p>\n<p>Tahov\u00e1 pevnost piezokeraick\u00fdch materi\u00e1l\u016f se definuje jako maxim\u00e1ln\u00ed nap\u011bt\u00ed, kter\u00e9 materi\u00e1l vydr\u017e\u00ed p\u0159i tahov\u00e9m nam\u00e1h\u00e1n\u00ed, ne\u017e dojde k jeho destrukci.  Na rozd\u00edl od tlaku, kter\u00fd stla\u010duje materi\u00e1l, tahov\u00e9 nap\u011bt\u00ed ho natahuje.  U piezokeraick\u00fdch materi\u00e1l\u016f je tahov\u00e1 pevnost obvykle ni\u017e\u0161\u00ed ne\u017e tlakov\u00e1 pevnost, co\u017e je d\u016fle\u017eit\u00e9 br\u00e1t v \u00favahu p\u0159i jejich designu a aplikaci.  Hodnota tahov\u00e9 pevnosti se ud\u00e1v\u00e1 v jednotk\u00e1ch Pascal\u016f (Pa) nebo Megapascal\u016f (MPa).  Je ovlivn\u011bna mnoha faktory, v\u010detn\u011b slo\u017een\u00ed materi\u00e1lu, zp\u016fsobu v\u00fdroby a teplotn\u00edch podm\u00ednek.<\/p>\n<p>Faktory ovliv\u0148uj\u00edc\u00ed tahovou pevnost<\/p>\n<p>R\u016fzn\u00e9 piezokeraick\u00e9 materi\u00e1ly vykazuj\u00ed odli\u0161n\u00e9 hodnoty tahov\u00e9 pevnosti.  Tato variace je zp\u016fsobena \u0159adou faktor\u016f:<\/p>\n<ul>\n<li><strong>Slo\u017een\u00ed materi\u00e1lu:<\/strong>  Typ a pom\u011br jednotliv\u00fdch slo\u017eek v piezokeraick\u00e9 sm\u011bsi z\u00e1sadn\u011b ovliv\u0148uje mechanick\u00e9 vlastnosti, v\u010detn\u011b tahov\u00e9 pevnosti.  P\u0159\u00eddavek modifik\u00e1tor\u016f m\u016f\u017ee zlep\u0161it tahovou pevnost, ale m\u016f\u017ee z\u00e1rove\u0148 ovlivnit i jin\u00e9 vlastnosti, jako je piezoelektrick\u00fd koeficient.<\/li>\n<li><strong>Zp\u016fsob v\u00fdroby:<\/strong>  Procesy, jako je lisov\u00e1n\u00ed, sintrov\u00e1n\u00ed a p\u00f3rov\u00e1n\u00ed, ovliv\u0148uj\u00ed mikrostrukturu materi\u00e1lu a t\u00edm i jeho mechanick\u00e9 vlastnosti.  Precizn\u00ed kontrola t\u011bchto proces\u016f je kl\u00ed\u010dov\u00e1 pro dosa\u017een\u00ed po\u017eadovan\u00e9 tahov\u00e9 pevnosti.<\/li>\n<li><strong>Teplota:<\/strong>  Tahov\u00e1 pevnost piezokeraick\u00fdch materi\u00e1l\u016f se s teplotou m\u011bn\u00ed.  V\u011bt\u0161ina materi\u00e1l\u016f vykazuje pokles tahov\u00e9 pevnosti s rostouc\u00ed teplotou.<\/li>\n<li><strong>Vady materi\u00e1lu:<\/strong>  P\u0159\u00edtomnost trhlin, p\u00f3r\u016f a dal\u0161\u00edch defekt\u016f v materi\u00e1lu v\u00fdrazn\u011b sni\u017euje jeho tahovou pevnost.<\/li>\n<\/ul>\n<p>Porovn\u00e1n\u00ed tahov\u00e9 pevnosti r\u016fzn\u00fdch piezokeraick\u00fdch materi\u00e1l\u016f<\/p>\n<p>N\u00e1sleduj\u00edc\u00ed tabulka ukazuje p\u0159ibli\u017en\u00e9 hodnoty tahov\u00e9 pevnosti pro n\u011bkter\u00e9 b\u011b\u017en\u011b pou\u017e\u00edvan\u00e9 piezokeraick\u00e9 materi\u00e1ly:<\/p>\n<table class=\"table table-striped table-bordered\">\n<thead>\n<tr>\n<th>Materi\u00e1l<\/th>\n<th>Tahov\u00e1 pevnost (MPa)<\/th>\n<\/tr>\n<\/thead>\n<tbody>\n<tr>\n<td>PZT-4<\/td>\n<td>10-20<\/td>\n<\/tr>\n<tr>\n<td>PZT-5A<\/td>\n<td>15-25<\/td>\n<\/tr>\n<tr>\n<td>PZT-5H<\/td>\n<td>20-30<\/td>\n<\/tr>\n<tr>\n<td>Piezoelektrick\u00e1 keramika s vysokou tahovou pevnost\u00ed (speci\u00e1ln\u00ed kompozice)<\/td>\n<td>30-50<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<p><em>Pozn\u00e1mka: Uveden\u00e9 hodnoty jsou orienta\u010dn\u00ed a mohou se li\u0161it v z\u00e1vislosti na v\u00fdrobci a specifick\u00fdch podm\u00ednk\u00e1ch v\u00fdroby.<\/em><\/p>\n<p>D\u016fsledky n\u00edzk\u00e9 tahov\u00e9 pevnosti<\/p>\n<p>N\u00edzk\u00e1 tahov\u00e1 pevnost piezokeraick\u00fdch materi\u00e1l\u016f m\u016f\u017ee v\u00e9st k selh\u00e1n\u00ed sou\u010d\u00e1stek p\u0159i provozu.  To se m\u016f\u017ee projevit jako prask\u00e1n\u00ed, lom nebo deformace materi\u00e1lu.  Proto je d\u016fle\u017eit\u00e9 zvolit vhodn\u00fd materi\u00e1l s dostate\u010dnou tahovou pevnost\u00ed pro danou aplikaci.  V n\u011bkter\u00fdch p\u0159\u00edpadech je nutn\u00e9 pou\u017e\u00edt kompenza\u010dn\u00ed mechanismy, aby se minimalizovalo nap\u011bt\u00ed v materi\u00e1lu.<\/p>\n<p>Piezokeraick\u00e9 materi\u00e1ly jsou k\u0159ehk\u00e9 a jejich tahov\u00e1 pevnost je relativn\u011b n\u00edzk\u00e1 ve srovn\u00e1n\u00ed s jin\u00fdmi materi\u00e1ly.  P\u0159esn\u00e9 pochopen\u00ed t\u00e9to vlastnosti a jej\u00edch determinant\u016f je nezbytn\u00e9 pro \u00fasp\u011b\u0161n\u00fd n\u00e1vrh a aplikaci piezokeraick\u00fdch sou\u010d\u00e1stek v nejr\u016fzn\u011bj\u0161\u00edch technologi\u00edch.  P\u0159i n\u00e1vrhu je nutn\u00e9 br\u00e1t v \u00favahu v\u0161echny v\u00fd\u0161e uveden\u00e9 faktory a zvolit materi\u00e1l s dostate\u010dnou tahovou pevnost\u00ed pro danou aplikaci, aby se p\u0159ede\u0161lo selh\u00e1n\u00ed za\u0159\u00edzen\u00ed.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Piezokeraick\u00e9 materi\u00e1ly nach\u00e1zej\u00ed \u0161irok\u00e9 uplatn\u011bn\u00ed v mnoha oblastech, od senzor\u016f a aktu\u00e1tor\u016f a\u017e po gener\u00e1tory ultrazvuku. Jedn\u00edm z kl\u00ed\u010dov\u00fdch parametr\u016f, kter\u00e9 ur\u010duj\u00ed jejich vlastnosti a pou\u017eitelnost, je tahov\u00e1 pevnost. Pochopen\u00ed tohoto parametru je z\u00e1sadn\u00ed pro spr\u00e1vn\u00fd n\u00e1vrh a aplikaci piezokeraick\u00fdch sou\u010d\u00e1stek. Tento \u010dl\u00e1nek se podrobn\u011bji zab\u00fdv\u00e1 definic\u00ed a v\u00fdznamem tahov\u00e9 pevnosti piezokeraick\u00fdch materi\u00e1l\u016f. Definice tahov\u00e9<\/p>\n","protected":false},"author":1,"featured_media":611,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[6415],"tags":[],"class_list":["post-63456","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-blog","prodpage-classic"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/63456","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/comments?post=63456"}],"version-history":[{"count":0,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/posts\/63456\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media\/611"}],"wp:attachment":[{"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/media?parent=63456"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/categories?post=63456"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bjultrasonic.com\/cs\/wp-json\/wp\/v2\/tags?post=63456"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}