1. Lintlha tsa Macroscopic tse Tlatselletsang ho Hlahisoeng ha Crack
1.1 Nakong ea ho lahlela ho sa khaotseng, metsi a pholileng a fafatsoa ka ho toba holim'a ingot, ho etsa hore mocheso o phahame ka hare ho ingot. Sena se etsa hore ho be le tšubuhlellano e sa leka-lekaneng lipakeng tsa libaka tse fapaneng, ho baka ho ithiba le ho baka khatello ea mocheso. Tlas'a maemo a itseng a khatello ea maikutlo, likhatello tsena li ka lebisa ho ingot cracking.
1.2 Tlhahisong ea indasteri, ho phunyeha ha ingot hangata ho etsahala sethaleng sa pele sa ho lahla kapa ho qala e le li-microcracks tseo hamorao li atang nakong ea ho pholisa, tse ka 'nang tsa hasana ho pholletsa le ingot eohle. Ntle le ho phunyeha, liphoso tse ling tse kang li- shuts tse batang , warping , le ho fanyeha li ka boela tsa etsahala nakong ea pele ea ho lahla, e leng se etsang hore e be karolo ea bohlokoa ts'ebetsong eohle ea ho lahla.
1.3 Ho ba le monyetla oa ho ba le serame ka ho toba ho petsoha ho chesang ho susumetsoa haholo ke sebopeho sa lik'hemik'hale, lisebelisoa tse kholo tsa alloy, le bongata ba lisebelisoa tse hloekisang lijo-thollo tse sebelisoang.
1.4 Boikutlo bo chesang ba ho phunyeha ha li-alloys bo bakoa haholo ke likhatello tsa ka hare tse etsang hore ho thehoe li-voids le mapetsong. Sebopeho le kabo ea tsona li khethoa ke likarolo tsa alloying, boleng ba metallurgical e qhibilihisang, le mekhahlelo e sa khaotseng ea ho lahla. Haholo-holo, li-ingots tse kholo tsa 7xxx letoto la li-alloys tsa aluminium li tloaetse ho phatloha ho chesang ka lebaka la likarolo tse ngata tsa alloying, mekhahlelo e mengata ea ho tiisa, khatello e phahameng ea ho lahlela, karohano ea oxidation ea likarolo tsa alloy, boleng bo bobe ba metallurgic, le sebopeho se tlase mocheso oa kamore.
1.5 Liphuputso li bonts'itse hore masimo a motlakase le likarolo tsa alloying (ho kenyeletsoa lihloekisi tsa lijo-thollo, likarolo tse kholo tsa alloy, le trace elements) li ama haholo sebopeho sa microstructure le ts'oaetso e chesang ea li-alloys tse sa khaotseng tsa 7xxx.
1.6 Ho feta moo, ka lebaka la sebopeho se rarahaneng sa 7050 aluminium alloy le boteng ba likarolo tse nang le oxidized habonolo, ho qhibiliha ho atisa ho monya haedrojene e ngata. Sena, se kopantsoe le oxide inclusions, se lebisa ho phelisaneng ha khase le li-inclusions, e leng se etsang hore ho be le lihlahisoa tse ngata tsa hydrogen ho qhibiliha. Likahare tsa haerojene e se e le ntho ea bohlokoa e amang liphetho tsa tlhahlobo, boits'oaro ba ho robeha, le ts'ebetso ea mokhathala oa lisebelisoa tsa ingot tse sebetsitsoeng. Ka hona, ho itšetlehile ka mochine oa ho ba teng ha haedrojene ha ho qhibiliha, hoa hlokahala ho sebelisa mecha ea phatlalatso ea adsorption le lisebelisoa tsa ho hloekisa ho tlosa hydrogen le lintho tse ling tse kenyelletsoeng ho tsoa ho qhibiliha ho fumana motsoako o hloekisitsoeng haholo.
2. Lisosa tsa Microscopic tsa Crack Formation
2.1 Ingot hot cracking haholo-holo e khethoa ke sekhahla sa ho nyenyefatsa, sekhahla sa phepo, le boholo ba bohlokoa ba sebaka sa mushy. Haeba boholo ba sebaka sa mushy se feta moeli o boima, ho phatloha ho chesang ho tla etsahala.
2.2 Ka kakaretso, mokhoa oa ho tiisa li-alloys o ka aroloa ka mekhahlelo e mengata: ho fepa ka bongata, ho fepa ka interdendritic, karohano ea dendrite, le dendrite bridging.
2.3 Nakong ea mokhahlelo oa karohano ea dendrite, matsoho a dendrite a tlala haufi-ufi 'me phallo ea metsi e thibeloa ke tsitsipano ea holim'a metsi. The permeability ea sebaka sa mushy e fokotsehile, 'me ho lekaneng ho tiisa ho fokotseha le khatello ea mocheso ho ka lebisa ho microporosity kapa esita le mapetsong a chesang.
2.4 Mokhahlelong oa borokho oa dendrite, ke mokelikeli o monyenyane feela o setseng mateanong a mararo. Mothating ona, thepa e tiileng e na le matla a mangata le polasetiki, 'me boemo bo tiileng ke eona feela mokhoa oa ho lefella shrinkage e tiileng le khatello ea mocheso. Mekhahlelo ena e 'meli ke eona e nang le monyetla oa ho theha likheo tsa shrinkage kapa mapetsong a chesang.
3. Tokisetso ea Li-ingots tsa boleng bo holimo tse Thehiloeng ho Mechane ea Tlhahiso ea Crack
3.1 Li-ingots tsa slab tse boholo bo boholo hangata li bonts'a mapetsong a holim'a metsi, porosity ea ka hare, le li-inclusions, tse amang haholo boitšoaro ba mochine nakong ea ho tiisa alloy.
3.2 Thepa ea mochini ea alloy nakong ea ho tiisa haholo e itšetlehile ka likarolo tsa mohaho oa ka hare, ho kenyelletsa le boholo ba lijo-thollo, lihlahisoa tsa hydrogen, le maemo a kenyelletso.
3.3 Bakeng sa lisebelisoa tsa aluminium tse nang le mehaho ea dendritic, sebaka sa bobeli sa letsoho sa dendrite (SDAS) se ama haholo thepa ea mochine le mokhoa oa ho tiisa. Finer SDAS e lebisa ho theho ea pejana ea porosity le likaroloana tse phahameng tsa porosity, ho fokotsa khatello ea maikutlo bakeng sa ho phatloha ho chesang.
3.4 Mefokolo e kang interdendritic shrinkage voids le inclusions e fokolisa haholo ho tiea ha skeleton e tiileng le ho fokotsa haholo khatello ea kelello e hlokahalang bakeng sa ho phatloha ho chesang.
3.5 Moralo oa lijo-thollo ke ntlha e 'ngoe ea bohlokoa ea microstructural e susumetsang boitšoaro bo chesang. Ha lijo-thollo li fetoha ho tloha ho li-columnar dendrites ho ea ho globular equiaxed grains, motsoako o bonts'a mocheso o tlase o tsitsitseng le ho ntlafala ha metsi a interdendritic, e leng se thibelang kholo ea pore. Ho feta moo, lijo-thollo tse ntle li ka amohela khatello e kholoanyane le maemo a khatello 'me tsa hlahisa litsela tse rarahaneng tsa ho jala crack, ka hona li fokotsa tloaelo ea ho phatloha ho hoholo.
3.6 Ka tlhahiso e sebetsang, ho ntlafatsa mekhoa ea ho sebetsana le ho qhibiliha le ho lahla-tse kang ho laola ka thata ho kenyelletsoa le lihlahisoa tsa hydrogen, hammoho le sebopeho sa lijo-thollo-ho ka ntlafatsa ho hanyetsa ka hare ho li-ingots tsa slab ho phatloha ho chesang. E kopantsoe le mekhoa e ntlafalitsoeng ea lisebelisoa le mekhoa ea ho sebetsa, mehato ena e ka lebisa tlhahisong ea lihlahisoa tse phahameng, tse kholo, tsa boleng bo phahameng ba li-slab.
4. Ntlafatso ea lijo-thollo tsa Ingot
7050 aluminium alloy haholo-holo e sebelisa mefuta e 'meli ea lihloekisi tsa lijo-thollo: Al-5Ti-1B le Al-3Ti-0.15C. Lithuto tsa papiso mabapi le ts'ebeliso ea marang-rang ea lihloekisi tsena li bonts'a:
Li-ingots tsa 4.1 tse ntlafalitsoeng ka Al-5Ti-1B li bonts'a boholo ba lijo-thollo tse nyane haholo le phetoho e ts'oanang ho tloha pheletsong ea ingot ho ea bohareng. Sekhahla sa mahoashe se tšesaane, 'me phello ea ho hloekisa lijo-thollo ka kakaretso e matla ho pholletsa le ingot.
4.2 Ha lisebelisoa tse tala tse neng li hloekisitsoe pele ka Al-3Ti-0.15C li sebelisoa, phello ea ntlafatso ea lijo-thollo ea Al-5Ti-1B ea fokotseha. Ho feta moo, ho eketsa keketso ea Al-Ti-B ho feta ntlha e itseng ha ho ntlafatse ntlafatso ea lijo-thollo ka tsela e lekanang. Ka hona, litlatsetso tsa Al-Ti-B ha lia lokela ho fokotsoa ho feta 2 kg / t.
Li-ingots tse 4.3 tse hloekisitsoeng ka Al-3Ti-0.15C li na le lithollo tse ntle, tse nang le globular equiaxed. Boholo ba lijo-thollo bo batla bo tšoana ka bophara ba letlapa. Keketso ea 3-4 kg / t ea Al-3Ti-0.15C e atleha ho tsitsisa boleng ba sehlahisoa.
4.4 Ka ho hlakileng, ha Al-5Ti-1B e sebelisoa ka motsoako oa 7050, likaroloana tsa TiB₂ li atisa ho arohana ho ea filimi ea oxide holim'a ingot holim'a maemo a pholileng ka potlako, ho etsa lihlopha tse lebisang ho thehoa ha slag. Nakong ea ho tiea ha ingot, lihlopha tsena li honyela ka hare ho etsa mameno a kang a groove, a fetolang tsitsipano ea holim'a ho qhibiliha. Sena se eketsa viscosity ea qhibiliha 'me se fokotsa mokelikeli, e leng se khothalletsang sebopeho sa crack botlaaseng ba hlobo le likhutlong tsa lifahleho tse sephara le tse moqotetsane tsa ingot. Sena se phahamisa haholo tloaelo ea ho peperana mme se ama chai ea ingot hampe.
4.5 Ha ho nahanoa ka boitšoaro ba ho theha 7050 alloy, sebopeho sa lijo-thollo tsa li-ingots tse tšoanang tsa malapeng le tsa machaba, le boleng ba lihlahisoa tsa ho qetela tse entsoeng, Al-3Ti-0.15C e khethoa e le mochine o hloekisang oa lijo-thollo bakeng sa ho lahla 7050 alloy-ntle le haeba maemo a itseng a hloka ho fapaneng.
5. Boitšoaro ba ntlafatso ea lijo-thollo tsa Al-3Ti-0.15C
5.1 Ha sehloekisi sa lijo-thollo se eketsoa ka 720 ° C, lithollo li na le meaho e leka-lekaneng e nang le likaroloana tse ling 'me ke tse ntle ka ho fetisisa ka boholo.
5.2 Haeba ho qhibiliha ho ts'oaroa nako e telele haholo ka mor'a ho kenya mochini o hloekisang (mohlala, ho feta metsotso e 10), kholo e mahoashe ea dendritic e atile, e bakang lijo-thollo tse mahoashe.
5.3 Ha palo ea tlatsetso ea mochini o hloekisang lijo-thollo e le 0.010% ho isa ho 0.015%, lijo-thollo tse ntle tse lekantsoeng lia fihlelleha.
5.4 Ho ipapisitsoe le ts'ebetso ea indasteri ea 7050 alloy, maemo a nepahetseng a ntlafatso ea lijo-thollo ke: mocheso o eketsehileng o pota-potileng 720 ° C, nako ea ho tloha ho phaella ho tiisa ho qetela ho laoloa ka hare ho metsotso ea 20, le tekanyo ea ho hloekisa hoo e ka bang 0.01-0.015% (3-4 kg / t ea Al-3Ti-0.15C).
5.5 Leha ho na le phapang ea boholo ba ingot, kakaretso ea nako ho tloha ho eketsa mochini o hloekisang lijo-thollo ka mor'a ho tsoa, ho pholletsa le tsamaiso ea in-line, trough, le hlobo, ho fihlela ho tiisa ho qetela ke metsotso e 15-20.
5.6 Libakeng tsa indasteri, ho eketsa palo ea lihlahisoa tsa lijo-thollo ho feta tekanyo ea Ti ea 0.01% ha e ntlafatse haholo ntlafatso ea lijo-thollo. Ho e-na le hoo, ho eketsa ka mokhoa o feteletseng ho lebisa katlehong ea Ti le C, ho eketsa menyetla ea ho ba le bokooa ba lintho tse bonahalang.
5.7 Liteko lintlheng tse fapaneng-degas inlet, degas outlet, le trough ea ho lahlela-li bontša phapang e fokolang ea boholo ba lijo-thollo. Leha ho le joalo, ho eketsa mohloekisi ka ho toba sebakeng sa ho lahla ntle le ho sefa ho eketsa kotsi ea likoli nakong ea tlhahlobo ea ultrasonic ea thepa e sebetsitsoeng.
5.8 Ho etsa bonnete ba hore lijo-thollo li ntlafatsoa ka mokhoa o ts'oanang le ho thibela ho bokellana ha sehloeki, mochini o hloekisang lijo-thollo o lokela ho eketsoa moo ho kenang mochine oa degassing.
Nako ea poso: Jul-16-2025
