{"id":8805,"date":"2025-06-15T02:00:17","date_gmt":"2025-06-15T02:00:17","guid":{"rendered":"https:\/\/premiumalu.com\/7021-aluminum-the-ultimate-guide-to-its-uses\/"},"modified":"2026-08-19T10:29:13","modified_gmt":"2026-08-19T10:29:13","slug":"7021-hlinik-pruvodce-jeho-pouzitim","status":"publish","type":"post","link":"https:\/\/premiumalu.com\/cs\/7021-aluminum-the-ultimate-guide-to-its-uses\/","title":{"rendered":"Objevte hlin\u00edk 7021: Vydejte se na cestu k 702 hlin\u00edku."},"content":{"rendered":"

Co je slitina hlin\u00edku 7021?<\/h2>\n\n\n\n

7021 je hlin\u00edkov\u00e1 slitina \u0159ady 7000, kter\u00e1 vyu\u017e\u00edv\u00e1 zinek (5,0\u20136,0%) jako prim\u00e1rn\u00ed zpev\u0148uj\u00edc\u00ed prvek, dopln\u011bn\u00fd ho\u0159\u010d\u00edkem (1,2\u20131,8%) a m\u011bd\u00ed (1,2\u20132,0%). Je precipita\u010dn\u011b zpevn\u011bn\u00e1 \u2014 pevnost poch\u00e1z\u00ed z \u0159\u00edzen\u00e9ho tepeln\u00e9ho zpracov\u00e1n\u00ed, nikoli z tv\u00e1\u0159en\u00ed za studena. Slitina pat\u0159\u00ed do rodiny Al-Zn-Mg-Cu, stejn\u00e9 skupiny jako 7075, ale jej\u00ed slo\u017een\u00ed je vylad\u011bno pro jin\u00fd kompromis: m\u00edrn\u011b ni\u017e\u0161\u00ed maxim\u00e1ln\u00ed pevnost v\u00fdm\u011bnou za v\u00fdrazn\u011b lep\u0161\u00ed sva\u0159itelnost a p\u0159im\u011b\u0159enou hou\u017eevnatost v tepeln\u011b ovlivn\u011bn\u00e9 oblasti.<\/p>\n\n\n\n

Pr\u00e1v\u011b sva\u0159itelnost odli\u0161uje 7021 od zbytku \u0159ady 7000. V\u011bt\u0161ina slitin 7xxx \u2014 zejm\u00e9na 7075 \u2014 je v podstat\u011b nesva\u0159iteln\u00e1 tavn\u00fdmi procesy. Slitina 7021 byla vyvinuta speci\u00e1ln\u011b pro aplikace, kde mus\u00ed b\u00fdt vysok\u00e1 pevnost kombinov\u00e1na se schopnost\u00ed spojovat sou\u010d\u00e1sti sva\u0159ov\u00e1n\u00edm. Cenou je odolnost proti korozi: jako v\u0161echny slitiny hlin\u00edku bohat\u00e9 na zinek vy\u017eaduje 7021 ochrann\u00fd povlak nebo eloxov\u00e1n\u00ed pro jak\u00e9koli venkovn\u00ed pou\u017eit\u00ed nebo prost\u0159ed\u00ed s vysokou vlhkost\u00ed. Pokud m\u00e1 b\u00fdt d\u00edl sva\u0159ov\u00e1n a pot\u0159ebuje pevnost \u0159ady 7000, je 7021 jednou z m\u00e1la slitin, kter\u00e1 tuto kombinaci \u010din\u00ed praktickou.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Chemick\u00e9 slo\u017een\u00ed a mechanick\u00e9 vlastnosti<\/h2>\n\n\n\n

Chemick\u00e9 slo\u017een\u00ed<\/h3>\n\n\n\n

Pevnostn\u00ed profil slitiny je ur\u010den p\u0159edev\u0161\u00edm zinkem a ho\u0159\u010d\u00edkem, kter\u00e9 b\u011bhem um\u011bl\u00e9ho st\u00e1rnut\u00ed tvo\u0159\u00ed zpev\u0148uj\u00edc\u00ed precipit\u00e1ty. M\u011b\u010f p\u0159id\u00e1v\u00e1 sekund\u00e1rn\u00ed zpev\u0148uj\u00edc\u00ed \u00fa\u010dinek a zlep\u0161uje odolnost proti mezikrystalov\u00e9 korozi pod nap\u011bt\u00edm. Zirkonium (0,08\u20130,18%) hraje struktur\u00e1ln\u00ed roli: zvy\u0161uje teplotu rekrystalizace, co\u017e pom\u00e1h\u00e1 slitin\u011b zachovat jemnou zrnitou strukturu b\u011bhem tepeln\u00e9ho zpracov\u00e1n\u00ed a sva\u0159ovac\u00edch cykl\u016f. Chrom (0,10\u20130,25%) zaji\u0161\u0165uje dodate\u010dn\u00e9 ukotven\u00ed hranic zrn.<\/p>\n\n\n\n

Prvek<\/strong><\/td>Rozsah slo\u017een\u00ed (% hmotnostn\u011b)<\/strong><\/td>Role<\/strong><\/td><\/tr>
Hlin\u00edk (Al)<\/td>Zbytek (~90,7\u201393,7)<\/td>Nobelmetal<\/td><\/tr>
Zinek (Zn)<\/td>5.0\u20136.0<\/td>Prim\u00e1rn\u00ed zpev\u0148uj\u00edc\u00ed prvek<\/td><\/tr>
Ho\u0159\u010d\u00edk (Mg)<\/td>1.2\u20131.8<\/td>Tv\u016frce precipit\u00e1t\u016f; pevnost + koroze<\/td><\/tr>
M\u011b\u010f (Cu)<\/td>1.2\u20132.0<\/td>Sekund\u00e1rn\u00ed zpevn\u011bn\u00ed; odolnost proti korozi pod nap\u011bt\u00edm<\/td><\/tr>
Mangan (Mn)<\/td>0.10\u20130.40<\/td>\u0158\u00edzen\u00ed zrnit\u00e9 struktury<\/td><\/tr>
Chrom (Cr)<\/td>0.10\u20130.25<\/td>Stabilizace hranic zrn<\/td><\/tr>
Zirkonium (Zr)<\/td>0.08\u20130.18<\/td>Zv\u00fd\u0161en\u00ed teploty rekrystalizace<\/td><\/tr>
K\u0159em\u00edk (Si)<\/td>\u22640,40<\/td>Limit ne\u010distot<\/td><\/tr>
\u017delezo (Fe)<\/td>\u22640,50<\/td>Limit ne\u010distot<\/td><\/tr>
Titan (Ti)<\/td>\u22640,10<\/td>Zjem\u0148ova\u010d zrna<\/td><\/tr>
Ostatn\u00ed (ka\u017ed\u00fd)<\/td>\u22640,05<\/td>Stopov\u00e9 prvky<\/td><\/tr>
Ostatn\u00ed (celkem)<\/td>\u22640,15<\/td>Celkov\u00e9 stopov\u00e9 prvky<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Mechanick\u00e9 vlastnosti (stav T6)<\/h3>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Nen\u00ed-li uvedeno jinak, n\u00ed\u017ee uveden\u00e9 hodnoty plat\u00ed pro 7021 ve stavu T6 \u2014 roztokov\u011b \u017e\u00edh\u00e1no a um\u011ble st\u00e1rnuto na maxim\u00e1ln\u00ed pevnost. Toto je z\u00e1kladn\u00ed stav pro konstruk\u010dn\u00ed aplikace.<\/p>\n\n\n\n

Majetek<\/strong><\/td>Hodnota<\/strong><\/td>Pozn\u00e1mky<\/strong><\/td><\/tr>
Hustota<\/td>2,78 g\/cm\u00b3<\/td>Typick\u00e9 pro \u0159adu 7xxx<\/td><\/tr>
Mez pevnosti v tahu<\/td>470 MPa (68 ksi)<\/td>Pod\u00e9ln\u00fd sm\u011br, pokojov\u00e1 teplota<\/td><\/tr>
Mez kluzu v tahu (0,2 % offset)<\/td>420 MPa (61 ksi)<\/td>N\u00e1vrhov\u00e1 rozhoduj\u00edc\u00ed hodnota pro konstruk\u010dn\u00ed d\u00edly<\/td><\/tr>
Prodlou\u017een\u00ed p\u0159i p\u0159etr\u017een\u00ed<\/td>~10%<\/td>P\u0159i m\u011brn\u00e9 d\u00e9lce 50 mm<\/td><\/tr>
Modul pru\u017enosti<\/td>71 GPa (10 300 ksi)<\/td>P\u0159ibli\u017en\u011b jedna t\u0159etina oceli<\/td><\/tr>
Mez \u00fanavy (5\u00d710\u2078 cykl\u016f)<\/td>~150 MPa (22 ksi)<\/td>Hladk\u00fd vzorek, R = \u22121<\/td><\/tr>
Smykov\u00e1 pevnost<\/td>270 MPa (39 ksi)<\/td>Relevantn\u00ed pro n\u00e1vrh n\u00fdtovan\u00fdch a \u0161roubovan\u00fdch spoj\u016f<\/td><\/tr>
Tvrdost<\/td>~120 HB<\/td>Zat\u00ed\u017een\u00ed 500 kg, kuli\u010dka 10 mm<\/td><\/tr>
Tepeln\u00e1 vodivost<\/td>150 W\/m\u00b7K<\/td>St\u0159edn\u00ed; dostate\u010dn\u00e1 pro v\u011bt\u0161inu konstruk\u010dn\u00edch aplikac\u00ed<\/td><\/tr>
Elektrick\u00e1 vodivost<\/td>38% IACS<\/td>Typick\u00e9 pro slitiny bohat\u00e9 na zinek<\/td><\/tr>
Rozsah t\u00e1n\u00ed<\/td>510\u2013630 \u00b0C<\/td>Solidus a\u017e likvidus<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Mez kluzu 420 MPa \u0159ad\u00ed 7021-T6 v\u00fdrazn\u011b nad 6061-T6 (276 MPa) a pevn\u011b do kategorie vysoce pevn\u00fdch hlin\u00edkov\u00fdch slitin. Ta\u017enost 10% je ni\u017e\u0161\u00ed ne\u017e ta\u017enost typick\u00e1 pro slitiny 5xxx nebo 6xxx, co\u017e je d\u016fle\u017eit\u00e9, pokud d\u00edl vy\u017eaduje tv\u00e1\u0159en\u00ed po v\u00fdrob\u011b \u2014 7021 ve stavu T6 nen\u00ed tv\u00e1\u0159ec\u00ed slitina. Kompromisem je pevnost za ta\u017enost, a pro konstruk\u010dn\u00ed aplikace, kde statick\u00e1 \u00fanosnost \u0159\u00edd\u00ed n\u00e1vrh, je mez kluzu n\u00e1vrhovou rozhoduj\u00edc\u00ed hodnotou.<\/p>\n\n\n\n

Kde se 7021 pou\u017e\u00edv\u00e1<\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Definuj\u00edc\u00ed v\u00fdhodou slitiny 7021 je kombinace pevnosti a sva\u0159itelnosti. V\u011bt\u0161ina aplikac\u00ed spad\u00e1 do kategori\u00ed, kde by 7075 byla z\u0159ejmou volbou z hlediska pevnosti, ale d\u00edl mus\u00ed b\u00fdt spojen sva\u0159ov\u00e1n\u00edm.<\/p>\n\n\n\n

1. Sva\u0159ovan\u00e9 konstruk\u010dn\u00ed sestavy<\/h3>\n\n\n\n

Sva\u0159ovan\u00e9 dopravn\u00ed konstrukce \u2014 r\u00e1my n\u00e1kladn\u00edch vozidel, podvozky p\u0159\u00edv\u011bs\u016f, sou\u010d\u00e1sti kolejov\u00fdch vozidel \u2014 pou\u017e\u00edvaj\u00ed 7021 tam, kde jsou vy\u017eadov\u00e1ny jak vysok\u00e1 pevnost, tak tavn\u00e9 sva\u0159ov\u00e1n\u00ed. Odolnost slitiny proti hork\u00e9mu trhlin\u00e1m je v\u00fdrazn\u011b lep\u0161\u00ed ne\u017e u 7075, co\u017e ji \u010din\u00ed vhodnou pro MIG a TIG s kvalifikovanou v\u00fdpln\u00ed \u0159ady 5xxx (5356 nebo 5183). Sva\u0159ovan\u00fd spoj z\u016fst\u00e1v\u00e1 n\u00e1vrhov\u011b limituj\u00edc\u00edm m\u00edstem.<\/p>\n\n\n\n

2. Leteck\u00e9 sva\u0159ovan\u00e9 sou\u010d\u00e1sti<\/h3>\n\n\n\n

V letectv\u00ed se 7021 vyskytuje ve sva\u0159ovan\u00fdch podsestav\u00e1ch \u2014 r\u00e1my n\u00e1kladn\u00edch kontejner\u016f, v\u00fdztu\u017en\u00e9 sestavy, sekund\u00e1rn\u00ed konstruk\u010dn\u00ed konzoly \u2014 kde by nesva\u0159itelnost slitiny 7075 vynutila n\u00fdtovan\u00fd nebo \u0161roubovan\u00fd n\u00e1vrh zvy\u0161uj\u00edc\u00ed hmotnost. Nejedn\u00e1 se o slitinu pro potah trupu nebo nosn\u00edky k\u0159\u00eddel; ty z\u016fst\u00e1vaj\u00ed dom\u00e9nou slitin 2024 a 7075.<\/p>\n\n\n\n

3. V\u00fdroba forem a n\u00e1stroj\u016f<\/h3>\n\n\n\n

Slitina 7021-T6 se pou\u017e\u00edv\u00e1 pro vst\u0159ikovac\u00ed formy na plasty a n\u00e1stroje pro vyfukovac\u00ed formy tam, kde z\u00e1le\u017e\u00ed na vysok\u00e9 pevnosti v tlaku, tepeln\u00e9 vodivosti a obrobitelnosti. Ve srovn\u00e1n\u00ed s n\u00e1strojov\u00fdmi ocelemi zkracuje hlin\u00edkov\u00e9 n\u00e1strojov\u00e9 vybaven\u00ed doby cykl\u016f d\u00edky rychlej\u0161\u00edmu p\u0159enosu tepla a 7021 poskytuje lep\u0161\u00ed pevnost ne\u017e 6061 nebo 5083 ve stejn\u00e9 roli.<\/p>\n\n\n\n

4. Je\u0159\u00e1by, zdvihac\u00ed za\u0159\u00edzen\u00ed a t\u011b\u017ek\u00e9 sva\u0159ovan\u00e9 konstrukce<\/h3>\n\n\n\n

Nosn\u00edky mostov\u00fdch je\u0159\u00e1b\u016f, zdvihac\u00ed ramena a velk\u00e9 sva\u0159ovan\u00e9 konstrukce t\u011b\u017e\u00ed ze sva\u0159itelnosti slitiny 7021 tam, kde je mechanick\u00e9 spojov\u00e1n\u00ed samo o sob\u011b nepraktick\u00e9. Materi\u00e1l zvl\u00e1d\u00e1 koncentrace nap\u011bt\u00ed kolem sva\u0159ovan\u00fdch p\u0159ipojovac\u00edch bod\u016f l\u00e9pe ne\u017e alternativy \u0159ady 6xxx, a to za ni\u017e\u0161\u00ed n\u00e1klady ne\u017e titan nebo ocel p\u0159i ekvivalentn\u00ed pevnosti.<\/p>\n\n\n\n

Mo\u017enosti stav\u016f slitiny 7021<\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Slitina 7021 se nej\u010dast\u011bji dod\u00e1v\u00e1 ve t\u0159ech stavech, p\u0159i\u010dem\u017e ka\u017ed\u00fd \u0159e\u0161\u00ed jin\u00fd po\u017eadavek na zpracov\u00e1n\u00ed.<\/p>\n\n\n\n

Temperament<\/strong><\/td>Zpracov\u00e1n\u00ed<\/strong><\/td>Mez pevnosti (MPa)<\/strong><\/td>MS (MPa)<\/strong><\/td>Prodlou\u017een\u00ed<\/strong><\/td>Nejlep\u0161\u00ed pro<\/strong><\/td>Vyhn\u011bte se, kdy\u017e<\/strong><\/td><\/tr>
T6<\/td>Roztokov\u011b \u017e\u00edh\u00e1no + um\u011ble st\u00e1rnuto<\/td>470<\/td>420<\/td>~10%<\/td>Obecn\u00e9 konstruk\u010dn\u00ed d\u00edly: pevnost v dodan\u00e9m stavu bez n\u00e1sledn\u00e9ho zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed<\/td>P\u0159esn\u00e9 tv\u00e1\u0159en\u00ed nebo oh\u00fdb\u00e1n\u00ed po\u017eadovan\u00e9 po tepeln\u00e9m zpracov\u00e1n\u00ed<\/td><\/tr>
T651<\/td>T6 + relaxace pnut\u00ed tahem (1\u20133%)<\/td>470<\/td>420<\/td>~10%<\/td>Obr\u00e1b\u011bn\u00e9 sou\u010d\u00e1sti, kde mus\u00ed b\u00fdt zbytkov\u00e9 pnut\u00ed uvoln\u011bno p\u0159ed odeb\u00edr\u00e1n\u00edm materi\u00e1lu<\/td>\u2014 (funk\u010dn\u011b identick\u00e9 s T6 pro v\u011bt\u0161inu neobr\u00e1b\u011bc\u00edch aplikac\u00ed)<\/td><\/tr>
T62<\/td>Roztokov\u011b \u017e\u00edh\u00e1no + um\u011ble st\u00e1rnuto z u\u017eivatelem proveden\u00e9ho zpracov\u00e1n\u00ed<\/td>~470<\/td>~420<\/td>~10%<\/td>D\u00edly, kter\u00e9 byly roztokov\u011b \u017e\u00edh\u00e1ny a st\u00e1rnuty jako vyroben\u00e1 sestava, nikoli jako v\u00fdchoz\u00ed polotovar<\/td>Objedn\u00e1v\u00e1n\u00ed surov\u00e9ho materi\u00e1lu \u2014 specifikujte T6 nebo T651<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

T6: Standardn\u00ed stav<\/h3>\n\n\n\n

T6 je standardn\u00ed stav pro v\u011bt\u0161inu aplikac\u00ed slitiny 7021. Materi\u00e1l je dod\u00e1v\u00e1n pln\u011b vytvrzen\u00fd a p\u0159ipraven\u00fd k v\u00fdrob\u011b \u2014 sva\u0159ov\u00e1n\u00ed, obr\u00e1b\u011bn\u00ed a mont\u00e1\u017ei. Mez kluzu 420 MPa je n\u00e1vrhovou hodnotou.<\/p>\n\n\n\n

T651: Odpru\u017een\u00fd pro obr\u00e1b\u011bn\u00ed<\/h3>\n\n\n\n

Pokud bude d\u00edl siln\u011b obr\u00e1b\u011bn \u2014 hlubok\u00e9 kapsy, asymetrick\u00e9 odeb\u00edr\u00e1n\u00ed materi\u00e1lu, p\u0159\u00edsn\u00e9 tolerance rovinnosti \u2014 je T651 lep\u0161\u00ed volbou. Relaxace pnut\u00ed tahem redistribuuje zbytkov\u00e1 kali\u010dsk\u00e1 pnut\u00ed p\u0159es pr\u016f\u0159ez, \u010d\u00edm\u017e sni\u017euje deformace b\u011bhem obr\u00e1b\u011bn\u00ed. Mechanick\u00e9 vlastnosti jsou identick\u00e9 s T6; T651 poskytuje rozm\u011brovou stabilitu, nikoli vy\u0161\u0161\u00ed pevnost.<\/p>\n\n\n\n

Pozn\u00e1mka k T62<\/h3>\n\n\n\n

T62 popisuje stav, kdy v\u00fdrobce nebo zpracovatel prov\u00e1d\u00ed roztokov\u00e9 \u017e\u00edh\u00e1n\u00ed a st\u00e1rnut\u00ed na tvarovan\u00e9 nebo sestaven\u00e9 sou\u010d\u00e1sti, nikoli kdy\u017e hutn\u00ed z\u00e1vod dod\u00e1v\u00e1 materi\u00e1l v pln\u011b vytvrzen\u00e9m stavu. T62 nen\u00ed samostatn\u00e1 t\u0159\u00edda slitiny 7021 \u2014 popisuje zp\u016fsob zpracov\u00e1n\u00ed. P\u0159i objedn\u00e1v\u00e1n\u00ed surov\u00e9ho materi\u00e1lu specifikujte T6 (nebo T651 pro obr\u00e1b\u011bn\u00e9 d\u00edly). T62 je relevantn\u00ed, pokud se roztokov\u011b \u017e\u00edh\u00e1 sestava po sva\u0159ov\u00e1n\u00ed nebo tv\u00e1\u0159en\u00ed za \u00fa\u010delem obnoven\u00ed pln\u00e9 pevnosti.<\/p>\n\n\n\n

7021 vs 7075 vs 6061<\/h2>\n\n\n\n
\"\"<\/figure>\n\n\n\n

Tyto t\u0159i slitiny pokr\u00fdvaj\u00ed nejb\u011b\u017en\u011bj\u0161\u00ed rozhodnut\u00ed v oblasti vysoce pevn\u00fdch hlin\u00edkov\u00fdch slitin. N\u00ed\u017ee uveden\u00e1 tabulka mapuje kl\u00ed\u010dov\u00e1 v\u00fdb\u011brov\u00e1 krit\u00e9ria.<\/p>\n\n\n\n

Majetek<\/strong><\/td>7021-T6<\/a><\/strong><\/td>7075-T6<\/a><\/strong><\/td>6061-T6<\/a><\/strong><\/td><\/tr>
Pevnost v tahu (UTS)<\/td>470 MPa<\/td>572 MPa<\/td>310 MPa<\/td><\/tr>
Pevnost v tahu<\/td>420 MPa<\/td>503 MPa<\/td>276 MPa<\/td><\/tr>
Prodlou\u017een\u00ed<\/td>~10%<\/td>~11%<\/td>12\u201317%<\/td><\/tr>
Hustota<\/td>2,78 g\/cm\u00b3<\/td>2,81 g\/cm\u00b3<\/td>2,70 g\/cm\u00b3<\/td><\/tr>
Sva\u0159itelnost (tavn\u00fdm sva\u0159ov\u00e1n\u00edm)<\/td>Uspokojiv\u00e1 \u2014 vy\u017eaduje kvalifikovan\u00e9 procesy MIG\/TIG<\/td>\u0160patn\u00e1 \u2014 nedoporu\u010duje se pro tavn\u00e9 sva\u0159ov\u00e1n\u00ed<\/td>V\u00fdborn\u00e1 \u2014 v\u0161echny b\u011b\u017en\u00e9 procesy<\/td><\/tr>
Odolnost proti korozi<\/td>Omezen\u00e1 \u2014 vy\u017eaduje povlakov\u00e1n\u00ed nebo eloxov\u00e1n\u00ed<\/td>Omezen\u00e1 \u2014 vy\u017eaduje povlakov\u00e1n\u00ed nebo pl\u00e1tov\u00e1n\u00ed<\/td>Dobr\u00e1 \u2014 pou\u017eiteln\u00e1 v mnoha prost\u0159ed\u00edch bez ochrany<\/td><\/tr>
\u00danavov\u00e1 pevnost<\/td>~150 MPa<\/td>~160 MPa<\/td>~97 MPa<\/td><\/tr>
Obrobitelnost<\/td>Velmi dobr\u00e1<\/td>Dobr\u00fd<\/td>Dobr\u00fd<\/td><\/tr>
Typick\u00e9 aplikace<\/td>Sva\u0159ovan\u00e9 konstrukce, formy, sva\u0159ovan\u00e9 leteck\u00e9 podsestavy<\/td>Vysoce nam\u00e1han\u00e9 obr\u00e1b\u011bn\u00e9 sou\u010d\u00e1sti, drakov\u00e9 konstrukce<\/td>V\u0161eobecn\u00e1 v\u00fdroba, n\u00e1mo\u0159n\u00ed aplikace, architektura<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

Kdy je 7021 spr\u00e1vnou volbou<\/h3>\n\n\n\n

D\u00edl mus\u00ed b\u00fdt sva\u0159ov\u00e1n a vy\u017eaduje pevnost \u0159ady 7000. Slitina 7075 je v podstat\u011b nesva\u0159iteln\u00e1 \u2014 hork\u00e9 trhliny v oblasti svaru a v\u00fdrazn\u00e1 ztr\u00e1ta pevnosti v tepeln\u011b ovlivn\u011bn\u00e9 oblasti (HAZ) ji \u010din\u00ed nepraktickou pro sva\u0159ovan\u00e9 sestavy. Slitina 7021 byla vyvinuta pr\u00e1v\u011b pro toto omezen\u00ed. Pokud je sva\u0159ov\u00e1n\u00ed zp\u016fsobem spojov\u00e1n\u00ed a mez kluzu 276 MPa slitiny 6061 nesta\u010d\u00ed, je 7021 logick\u00fdm krokem vp\u0159ed.<\/p>\n\n\n\n

N\u00e1strojov\u00e9 formy, kde je pevnost d\u016fle\u017eit\u011bj\u0161\u00ed ne\u017e u slitiny 6061. Mez kluzu 420 MPa slitiny 7021 poskytuje n\u00e1stroj\u016fm pro vst\u0159ikov\u00e1n\u00ed plast\u016f a vyfukov\u00e1n\u00ed vy\u0161\u0161\u00ed tlakovou odolnost ne\u017e alternativy 6061 nebo 5083 za srovnateln\u00fdch n\u00e1klad\u016f.<\/p>\n\n\n\n

Kde je lep\u0161\u00ed 7075 nebo 6061<\/h3>\n\n\n\n

Maxim\u00e1ln\u00ed pevnost bez nutnosti sva\u0159ov\u00e1n\u00ed. Slitina 7075-T6 poskytuje p\u0159ibli\u017en\u011b o 15\u201318 % vy\u0161\u0161\u00ed mez kluzu ne\u017e 7021. Pro obr\u00e1b\u011bn\u00e9 konstruk\u010dn\u00ed sou\u010d\u00e1sti, leteck\u00e9 fitinky a vysoce nam\u00e1han\u00e9 d\u00edly spojovan\u00e9 \u0161rouby nebo n\u00fdty je 7075 pevn\u011bj\u0161\u00ed volbou. Kompletn\u00ed \u00fadaje o vlastnostech naleznete v pr\u016fvodci hlin\u00edkovou slitinou 7075.<\/p>\n\n\n\n

V\u0161eobecn\u00e1 v\u00fdroba s dobrou korozn\u00ed odolnost\u00ed. Slitina 6061-T6 je sva\u0159iteln\u00e1, tv\u00e1\u0159iteln\u00e1, korozn\u011b odoln\u00e1 a \u0161iroce dostupn\u00e1. Pro konstruk\u010dn\u00ed v\u00fdrobu, kde je mez kluzu 276 MPa dosta\u010duj\u00edc\u00ed a z\u00e1le\u017e\u00ed na jednoduchosti sva\u0159ov\u00e1n\u00ed, je 6061 standardem. Pr\u016fvodce hlin\u00edkovou slitinou 6061 pokr\u00fdv\u00e1 cel\u00fd profil.<\/p>\n\n\n\n

Pr\u00e1ce s hlin\u00edkovou slitinou 7021<\/h2>\n\n\n\n

Obr\u00e1b\u011bn\u00ed<\/h3>\n\n\n\n

Slitina 7021 se velmi dob\u0159e obr\u00e1b\u00ed karbidov\u00fdmi n\u00e1stroji p\u0159i vysok\u00fdch ot\u00e1\u010dk\u00e1ch v\u0159etena. Tvorba t\u0159\u00edsky je \u010dist\u00e1 a kontrola t\u0159\u00edsky zvl\u00e1dnuteln\u00e1 \u2014 lep\u0161\u00ed ne\u017e u 6061 a p\u0159ibli\u017en\u011b srovnateln\u00e1 s 7075. Pokud geometrie d\u00edlu zahrnuje hlubok\u00e9 kapsy, asymetrick\u00e9 \u0159ezy nebo p\u0159\u00edsn\u00e9 tolerance rovinnosti, m\u011bl by b\u00fdt specifikov\u00e1n stav T651 nam\u00edsto T6, aby se zabr\u00e1nilo deformaci v d\u016fsledku uvoln\u011bn\u00ed zbytkov\u00fdch pnut\u00ed. Pro operace na plechu \u2014 o\u0159ez\u00e1v\u00e1n\u00ed, vrt\u00e1n\u00ed, lehk\u00e9 fr\u00e9zov\u00e1n\u00ed \u2014 je T6 stabiln\u00ed.<\/p>\n\n\n\n

Sva\u0159ov\u00e1n\u00ed<\/h3>\n\n\n\n

Tavn\u00e9 sva\u0159ov\u00e1n\u00ed slitiny 7021 je mo\u017en\u00e9, ale vy\u017eaduje v\u011bt\u0161\u00ed kontrolu procesu ne\u017e u slitin 5xxx nebo 6xxx. Slitina je ve srovn\u00e1n\u00ed s 7075 odoln\u00e1 v\u016f\u010di hork\u00fdm trhlin\u00e1m, ale nen\u00ed v\u016f\u010di nim imunn\u00ed. Kl\u00ed\u010dov\u00e9 postupy:<\/p>\n\n\n\n

    \n
  •  <\/strong>P\u0159\u00eddavn\u00fd materi\u00e1l.<\/strong> P\u0159\u00eddavn\u00e9 materi\u00e1ly \u0159ady 5xxx \u2014 5356 nebo 5183 \u2014 jsou standardn\u00ed volbou. Poskytuj\u00ed slo\u017een\u00ed svarov\u00e9 l\u00e1zn\u011b, kter\u00e9 odol\u00e1v\u00e1 trhlin\u00e1m p\u0159i tuhnut\u00ed p\u0159i zachov\u00e1n\u00ed p\u0159ijateln\u00e9 pevnosti spoje.<\/li>\n\n\n\n
  •  <\/strong>Kontrola tepeln\u00e9ho p\u0159\u00edkonu.<\/strong> Mezipr\u016fchodov\u00e1 teplota by m\u011bla z\u016fstat pod 150 \u00b0C (300 \u00b0F). Nadm\u011brn\u00fd tepeln\u00fd p\u0159\u00edkon zvy\u0161uje \u0161\u00ed\u0159ku tepeln\u011b ovlivn\u011bn\u00e9 oblasti a v\u00fdslednou ztr\u00e1tu pevnosti.<\/li>\n\n\n\n
  •  <\/strong>Tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed.<\/strong> Rozpou\u0161t\u011bc\u00ed \u017e\u00edh\u00e1n\u00ed a op\u011btovn\u00e9 vytvrzen\u00ed m\u016f\u017ee obnovit v\u00fdznamnou \u010d\u00e1st ztr\u00e1ty pevnosti v HAZ, ale p\u0159id\u00e1v\u00e1 cel\u00fd tepeln\u00fd cyklus do v\u00fdrobn\u00edho postupu a nemus\u00ed b\u00fdt praktick\u00e9 pro velk\u00e9 sestavy. Svary by m\u011bly b\u00fdt navr\u017eeny jako prvek omezuj\u00edc\u00ed pevnost konstrukce s odpov\u00eddaj\u00edc\u00edmi pr\u016f\u0159ezy.<\/li>\n\n\n\n
  •  <\/strong>T\u0159ec\u00ed m\u00edchac\u00ed sva\u0159ov\u00e1n\u00ed.<\/strong> Tam, kde to geometrie spoje umo\u017e\u0148uje, je t\u0159ec\u00ed m\u00edchac\u00ed sva\u0159ov\u00e1n\u00ed preferovan\u00fdm procesem. Z\u016fst\u00e1v\u00e1 pod teplotou rozpou\u0161t\u011bc\u00edho \u017e\u00edh\u00e1n\u00ed, \u010d\u00edm\u017e zachov\u00e1v\u00e1 v\u00edce pevnosti z\u00e1kladn\u00edho materi\u00e1lu ve spoji. Vy\u017eaduje v\u0161ak specializovan\u00e9 za\u0159\u00edzen\u00ed a je omezeno na tup\u00e9 a p\u0159epl\u00e1tovan\u00e9 spoje v ploch\u00fdch nebo v\u00e1lcov\u00fdch geometri\u00edch.<\/li>\n<\/ul>\n\n\n\n

    Korozn\u00ed ochrana<\/h3>\n\n\n\n

    Korozn\u00ed odolnost slitiny 7021 je omezen\u00e1 \u2014 vlastnost, kterou sd\u00edl\u00ed s t\u00e9m\u011b\u0159 v\u0161emi slitinami \u0159ady 7xxx. Hlin\u00edk bohat\u00fd na zinek je n\u00e1chyln\u00fd k obecn\u00e9 korozi i k nap\u011b\u0165ov\u00e9 korozn\u00ed praskavosti ve vlhk\u00e9m prost\u0159ed\u00ed nebo v prost\u0159ed\u00ed obsahuj\u00edc\u00edm chloridy. T\u0159i ochrann\u00e9 strategie pokr\u00fdvaj\u00ed v\u011bt\u0161inu aplikac\u00ed:<\/p>\n\n\n\n

      \n
    •  <\/strong>Eloxov\u00e1n\u00ed.<\/strong> Eloxov\u00e1n\u00ed v kyselin\u011b s\u00edrov\u00e9 (typ II) vytv\u00e1\u0159\u00ed \u0159\u00edzenou oxidovou bari\u00e9ru. Vysok\u00fd obsah zinku v\u0161ak m\u016f\u017ee v\u00e9st k m\u00e9n\u011b rovnom\u011brn\u00e9 anodick\u00e9 vrstv\u011b ne\u017e u slitin 6xxx a kvalita eloxov\u00e1n\u00ed se li\u0161\u00ed v z\u00e1vislosti na podm\u00ednk\u00e1ch l\u00e1zn\u011b a \u0161ar\u017ei slitiny. Tvrd\u00e9 eloxov\u00e1n\u00ed (typ III) je mo\u017en\u00e9, ale m\u016f\u017ee sn\u00ed\u017eit \u00fanavovou \u017eivotnost.<\/li>\n\n\n\n
    •  <\/strong>N\u00e1t\u011brov\u00e9 syst\u00e9my.<\/strong> Epoxidov\u00fd z\u00e1kladn\u00ed n\u00e1t\u011br s polyuretanov\u00fdm vrchn\u00edm n\u00e1t\u011brem je standardn\u00edm pr\u016fmyslov\u00fdm ochrann\u00fdm syst\u00e9mem. Pro vnit\u0159n\u00ed nebo zast\u0159e\u0161en\u00e9 aplikace m\u016f\u017ee posta\u010dovat jednovrstv\u00fd syst\u00e9m. P\u0159\u00edprava povrchu \u2014 chemick\u00e1 konverzn\u00ed vrstva (Alodine) nebo tenk\u00fd elox \u2014 je nezbytn\u00e1 pro p\u0159ilnavost n\u00e1t\u011bru.<\/li>\n\n\n\n
    •  <\/strong>Konstrukce odvodn\u011bn\u00ed.<\/strong> Je t\u0159eba se vyhnout m\u00edst\u016fm zachycuj\u00edc\u00edm vodu, \u0161t\u011brbin\u00e1m a vodorovn\u00fdm ploch\u00e1m, kde se m\u016f\u017ee hromadit vlhkost. Jednoduch\u00e1 geometrick\u00e1 \u0159e\u0161en\u00ed sni\u017euj\u00ed riziko koroze v\u00edce ne\u017e jak\u00fdkoli n\u00e1t\u011br.<\/li>\n<\/ul>\n\n\n\n

      V\u00fdhody a omezen\u00ed na prvn\u00ed pohled<\/h2>\n\n\n\n
      Faktor<\/strong><\/td>V\u00fdhoda<\/strong><\/td>Omezen\u00ed<\/strong><\/td><\/tr>
      S\u00edla<\/td>470 MPa pevnost v tahu, 420 MPa mez kluzu \u2014 v kategorii vysoce pevn\u00fdch hlin\u00edkov\u00fdch slitin<\/td>P\u0159ibli\u017en\u011b o 15\u201318 % ni\u017e\u0161\u00ed ne\u017e u 7075-T6 pro aplikace, kde rozhoduje mez kluzu<\/td><\/tr>
      Sva\u0159itelnost<\/td>Jedna z nejsva\u0159iteln\u011bj\u0161\u00edch slitin \u0159ady 7xxx; pou\u017eiteln\u00e1 s kvalifikovan\u00fdm MIG\/TIG<\/td>Vy\u017eaduje kontrolu procesu; ztr\u00e1ta pevnosti v HAZ je trval\u00e1 bez tepeln\u00e9ho zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed<\/td><\/tr>
      Obrobitelnost<\/td>Velmi dobr\u00e1 tvorba t\u0159\u00edsky a kvalita povrchu<\/td>Pro t\u011b\u017ek\u00e9 obr\u00e1b\u011bn\u00ed by m\u011bl b\u00fdt specifikov\u00e1n stav T651, aby se zabr\u00e1nilo deformaci<\/td><\/tr>
      Odolnost proti korozi<\/td>Dostate\u010dn\u00e1 s eloxov\u00e1n\u00edm nebo n\u00e1t\u011brem<\/td>Hol\u00e1 slitina nen\u00ed vhodn\u00e1 pro nechr\u00e1n\u011bn\u00e9 venkovn\u00ed nebo n\u00e1mo\u0159n\u00ed pou\u017eit\u00ed<\/td><\/tr>
      \u00danava<\/td>150 MPa \u2014 solidn\u00ed pro konstruk\u010dn\u00ed cyklick\u00e9 zat\u00ed\u017een\u00ed<\/td>Ni\u017e\u0161\u00ed ne\u017e u 7075 (160 MPa) a 2024 (140 MPa, ale s lep\u0161\u00edm chov\u00e1n\u00edm p\u0159i vrubov\u00e9 \u00fanav\u011b)<\/td><\/tr>
      Dostupnost<\/td>Standardn\u00ed v\u00e1lcovan\u00fd v\u00fdrobek ve form\u011b desek, ty\u010d\u00ed a profil\u016f<\/td>M\u00e9n\u011b b\u011b\u017en\u011b skladem ne\u017e 6061 nebo 7075; p\u0159ed n\u00e1vrhem na tuto slitinu ov\u011b\u0159te dostupnost<\/td><\/tr>
      Tvarovatelnost<\/td>Dostate\u010dn\u00e1 pro extrudovan\u00e9 profily<\/td>Nevhodn\u00e1 pro tv\u00e1\u0159en\u00ed za studena nebo oh\u00fdb\u00e1n\u00ed ve stavu T6<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

      Z\u00e1v\u011br<\/h2>\n\n\n\n

      Slitina 7021 zauj\u00edm\u00e1 \u00fazkou, ale jasn\u011b definovanou pozici v \u0159ad\u011b 7000: ob\u011btuje p\u0159ibli\u017en\u011b 15\u201318 % maxim\u00e1ln\u00ed pevnosti slitiny 7075 za schopnost tavn\u00e9ho sva\u0159ov\u00e1n\u00ed, ale omezen\u00e1 korozn\u00ed odolnost vy\u017eaduje ochrann\u00e9 o\u0161et\u0159en\u00ed a sva\u0159ov\u00e1n\u00ed vy\u017eaduje kvalifikovan\u00e9 procesy se spr\u00e1vn\u00fdm p\u0159\u00eddavn\u00fdm materi\u00e1lem a kontrolou tepla. Slitina 7021 je tak\u00e9 m\u00e9n\u011b b\u011b\u017en\u011b skladem ne\u017e 6061 nebo 7075, tak\u017ee potvrzen\u00ed dostupnosti a podpora zpracov\u00e1n\u00ed jsou p\u0159ed n\u00e1vrhem z\u00e1sadn\u00ed. <\/p>\n\n\n\n

      Spole\u010dnost Linsy Aluminum dod\u00e1v\u00e1 slitinu 7021 ve form\u011b desek, ty\u010d\u00ed, trubek, dr\u00e1t\u016f, svitk\u016f, profil\u016f a blok\u016f ve stavech T6 a T651 s dokumentac\u00ed MTC u ka\u017ed\u00e9 objedn\u00e1vky, protokoly SGS na vy\u017e\u00e1d\u00e1n\u00ed a vlastn\u00edm CNC obr\u00e1b\u011bn\u00edm, sva\u0159ov\u00e1n\u00edm MIG\/TIG, laserov\u00fdm \u0159ez\u00e1n\u00edm a povrchovou \u00fapravou; zak\u00e1zkov\u00e1 v\u00fdroba s n\u00edzk\u00fdm minim\u00e1ln\u00edm mno\u017estv\u00edm objedn\u00e1vky pokr\u00fdv\u00e1 nestandardn\u00ed rozm\u011bry s typickou dodac\u00ed lh\u016ftou 10\u201360 dn\u00ed. Za\u0161lete t\u0159\u00eddu 7021, formu, stav a po\u017eadovan\u00e9 rozm\u011bry pro p\u0159ezkoum\u00e1n\u00ed specifikace a potvrzen\u00ed dostupnosti.<\/p>\n\n\n\n

      \u010casto kladen\u00e9 ot\u00e1zky<\/h2>\n\n\n\n

      \u010c\u00edm se 7021 li\u0161\u00ed od 7075?<\/h3>\n\n\n\n

      Ob\u011b slitiny pat\u0159\u00ed do stejn\u00e9 rodiny Al-Zn-Mg-Cu, ale zam\u011b\u0159uj\u00ed se na r\u016fzn\u00e9 priority. Slitina 7075 je navr\u017eena pro maxim\u00e1ln\u00ed pevnost (572 MPa pevnost v tahu, 503 MPa mez kluzu ve stavu T6) za cenu praktick\u00e9 nesva\u0159itelnosti tavn\u00fdmi procesy. Slitina 7021 ob\u011btuje p\u0159ibli\u017en\u011b 15\u201318 % t\u00e9to meze kluzu za praktickou sva\u0159itelnost s kvalifikovan\u00fdmi procesy MIG\/TIG. Slitina 7021 je vhodnou volbou, pokud mus\u00ed b\u00fdt d\u00edl sva\u0159ov\u00e1n; 7075 je preferov\u00e1na pro maxim\u00e1ln\u00ed pevnost u \u0161roubovan\u00fdch, n\u00fdtovan\u00fdch nebo obr\u00e1b\u011bn\u00fdch sou\u010d\u00e1st\u00ed.<\/p>\n\n\n\n

      Lze slitinu 7021 sva\u0159ovat standardn\u00edm MIG za\u0159\u00edzen\u00edm?<\/h3>\n\n\n\n

      Ano, ale s kontrolami procesu, kter\u00e9 p\u0159esahuj\u00ed b\u011b\u017enou praxi u slitin 6xxx nebo 5xxx. P\u0159\u00eddavn\u00e9 materi\u00e1ly \u0159ady 5xxx (5356 nebo 5183) jsou standardn\u00ed volbou; mezipr\u016fchodov\u00e1 teplota by m\u011bla z\u016fstat pod 150 \u00b0C a spoj by m\u011bl b\u00fdt navr\u017een s o\u010dek\u00e1v\u00e1n\u00edm ur\u010dit\u00e9 ztr\u00e1ty pevnosti v HAZ. Pro kritick\u00e9 konstruk\u010dn\u00ed svary zachov\u00e1v\u00e1 t\u0159ec\u00ed m\u00edchac\u00ed sva\u0159ov\u00e1n\u00ed v\u00edce pevnosti spoje a m\u011blo by b\u00fdt zv\u00e1\u017eeno, pokud to geometrie d\u00edlu umo\u017e\u0148uje.<\/p>\n\n\n\n

      Jak\u00fd je rozd\u00edl mezi 7021-T6 a 7021-T651?<\/h3>\n\n\n\n

      Mechanick\u00e9 vlastnosti jsou identick\u00e9 \u2014 470 MPa pevnost v tahu, 420 MPa mez kluzu, ~10 % ta\u017enost. Rozd\u00edl spo\u010d\u00edv\u00e1 v kroku uvoln\u011bn\u00ed pnut\u00ed ta\u017een\u00edm (1\u20133 % prodlou\u017een\u00ed po ochlazen\u00ed) aplikovan\u00e9m ve stavu T651. Tento krok redistribuuje zbytkov\u00e1 pnut\u00ed z ochlazov\u00e1n\u00ed p\u0159es pr\u016f\u0159ez a sni\u017euje deformaci b\u011bhem obr\u00e1b\u011bn\u00ed. Pro d\u00edly, kter\u00e9 budou v\u00fdrazn\u011b obr\u00e1b\u011bny \u2014 hlubok\u00e9 kapsy, asymetrick\u00e9 \u0159ezy, p\u0159\u00edsn\u00e9 specifikace rovinnosti \u2014 je T651 bezpe\u010dn\u011bj\u0161\u00ed volbou. Pro v\u0161eobecnou v\u00fdrobu a sva\u0159ov\u00e1n\u00ed je standardem T6.<\/p>\n\n\n\n

      Jak si 7021 stoj\u00ed ve srovn\u00e1n\u00ed s 6061 pro konstruk\u010dn\u00ed v\u00fdrobu?<\/h3>\n\n\n\n

      Slitina 7021 poskytuje p\u0159ibli\u017en\u011b o 50 % vy\u0161\u0161\u00ed mez kluzu ne\u017e 6061-T6 (420 MPa vs. 276 MPa). Kompromisem je hor\u0161\u00ed korozn\u00ed odolnost, n\u00e1ro\u010dn\u011bj\u0161\u00ed po\u017eadavky na sva\u0159ov\u00e1n\u00ed, ni\u017e\u0161\u00ed ta\u017enost a obecn\u011b vy\u0161\u0161\u00ed n\u00e1klady na materi\u00e1l. Pokud aplikace m\u016f\u017ee dos\u00e1hnout sv\u00e9ho pevnostn\u00edho c\u00edle se slitinou 6061, snadn\u011bj\u0161\u00ed v\u00fdroba a lep\u0161\u00ed korozn\u00ed odolnost z n\u00ed \u010din\u00ed jednodu\u0161\u0161\u00ed volbu. Slitina 7021 je vhodnou volbou, kdy\u017e mez kluzu 276 MPa slitiny 6061 ponech\u00e1v\u00e1 p\u0159\u00edli\u0161 malou rezervu a sva\u0159ov\u00e1n\u00ed je st\u00e1le vy\u017eadov\u00e1no \u2014 pokud sva\u0159ov\u00e1n\u00ed nen\u00ed vy\u017eadov\u00e1no, m\u016f\u017ee b\u00fdt 7075 lep\u0161\u00edm pevnostn\u00edm vylep\u0161en\u00edm.<\/p>\n\n\n\n

      Vy\u017eaduje slitina 7021 korozn\u00ed ochranu v provozu?<\/h3>\n\n\n\n

      Ano \u2014 pro jakoukoli aplikaci nad r\u00e1mec such\u00e9ho vnit\u0159n\u00edho prost\u0159ed\u00ed. Hol\u00e1 slitina 7021 bude korodovat ve vlhk\u00fdch podm\u00ednk\u00e1ch a je n\u00e1chyln\u00e1 k nap\u011b\u0165ov\u00e9 korozn\u00ed praskavosti p\u0159i trval\u00e9m tahov\u00e9m nap\u011bt\u00ed. Eloxov\u00e1n\u00ed v kyselin\u011b s\u00edrov\u00e9 nebo pln\u00fd n\u00e1t\u011brov\u00fd syst\u00e9m (konverzn\u00ed vrstva + epoxidov\u00fd z\u00e1kladn\u00ed n\u00e1t\u011br + polyuretanov\u00fd vrchn\u00ed n\u00e1t\u011br) je minimem pro venkovn\u00ed nebo pr\u016fmyslov\u00e1 prost\u0159ed\u00ed. Pro n\u00e1mo\u0159n\u00ed nebo chemick\u00e9 prost\u0159ed\u00ed by m\u011bla b\u00fdt m\u00edsto toho zv\u00e1\u017eena jin\u00e1 rodina slitin \u2014 5xxx nebo 6xxx.<\/p>","protected":false},"excerpt":{"rendered":"

      What Is 7021 Aluminum? 7021 is a 7000-series aluminum alloy that uses zinc (5.0\u20136.0%) as its primary strengthening element, backed by magnesium (1.2\u20131.8%) and copper (1.2\u20132.0%). It is precipitation-hardened \u2014 strength comes from controlled heat treatment, not cold work. The alloy belongs to the Al-Zn-Mg-Cu family, the same group as 7075, but its composition is […]<\/p>\n","protected":false},"author":1,"featured_media":8794,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_seopress_titles_title":"7021 Aluminum: The Ultimate Guide to Properties and Uses","_seopress_titles_desc":"A practical guide to 7021 aluminum: chemical composition, mechanical properties, T6\/T62\/T651 tempers, comparison with 7075 and 6061, and sourcing tips for aerospace and structural use.","_seopress_robots_index":"","_seopress_robots_follow":"","_seopress_robots_imageindex":"","_seopress_robots_snippet":"","_seopress_robots_primary_cat":"","_seopress_robots_breadcrumbs":"","_seopress_robots_freeze_modified_date":"","_seopress_robots_custom_modified_date":"","_seopress_robots_canonical":"","_seopress_social_fb_title":"","_seopress_social_fb_desc":"","_seopress_social_fb_img":"","_seopress_social_fb_img_attachment_id":0,"_seopress_social_fb_img_width":0,"_seopress_social_fb_img_height":0,"_seopress_social_twitter_title":"","_seopress_social_twitter_desc":"","_seopress_social_twitter_img":"","_seopress_social_twitter_img_attachment_id":0,"_seopress_social_twitter_img_width":0,"_seopress_social_twitter_img_height":0,"_seopress_redirections_value":"","_seopress_redirections_enabled":"","_seopress_redirections_enabled_regex":"","_seopress_redirections_logged_status":"","_seopress_redirections_param":"","_seopress_redirections_type":0,"_seopress_analysis_target_kw":"","footnotes":""},"categories":[179],"tags":[],"class_list":["post-8805","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-7000-series-aluminum"],"_links":{"self":[{"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/posts\/8805","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/comments?post=8805"}],"version-history":[{"count":3,"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/posts\/8805\/revisions"}],"predecessor-version":[{"id":10316,"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/posts\/8805\/revisions\/10316"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/media\/8794"}],"wp:attachment":[{"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/media?parent=8805"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/categories?post=8805"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/premiumalu.com\/cs\/wp-json\/wp\/v2\/tags?post=8805"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}