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Mokhoa o mocha o thehiloeng holim'a ho qhibiliha ha laser ho khethang ho laola microstructure ea lihlahisoa ha ho etsoa proposed.The mechanism relies on the generation of high-intensity ultrasonic wave in the holten pool by complex intensity-modulated laser irradiation.Lithuto tsa liteko le lipapiso tsa lipalo li bontša hore mochine ona oa ho laola o khoneha ka tekheniki 'me o ka khona ho sebetsa ka mokhoa o atlehileng oa mochine oa kajeno oa laser.
Additive production (AM) ea likarolo tse rarahaneng-tse bōpehileng e eketsehile haholo lilemong tse mashome a morao tjena. Leha ho le joalo, ho sa tsotellehe mefuta e fapaneng ya dithulaganyo tsa tlatsetso tlhahiso, ho akarelletsa le selective laser melting (SLM) 1,2,3, ka ho toba laser tšepe deposition4,5,6, elektrone beam melting7,8 le others9,10, Likarolo ka 'na ba le sekoli.Sena ke haholo-holo ka lebaka la ho pholileng letamo tse phahameng tse amanang le ho qhibiliha ha grate e phahameng ea molten e amanang le likarolo tse phahameng tsa molten tse amanang le letamo litekanyetso, le ho rarahana ha lipotoloho tsa ho futhumatsa ha ho qhibiliha le ho tsosolosa thepa 11, e lebisang ho epitaxial lijo-thollo kgolo le porosity ea bohlokoa.12,13 e bontšitse hore hoa hlokahala ho laola li-gradients tsa mocheso, litekanyetso tsa ho pholisa, le motsoako oa motsoako, kapa ho sebelisa lits'oants'o tse eketsehileng tsa 'mele ka masimo a ka ntle a thepa e sa tšoaneng, e kang ultrasound, ho finyella mehaho e metle ea lijo-thollo tse lekanang.
Lingoliloeng tse ngata li amehile ka phello ea phekolo ea vibration ka mokhoa oa ho tiisa ts'ebetsong e tloaelehileng ea ho lahla14,15. Leha ho le joalo, ho sebelisa tšimo e ka ntle ho qhibiliha ka bongata ha ho hlahise thepa e lakatsehang ea microstructure.Haeba molumo oa karolo ea mokelikeli o le monyenyane, boemo bo fetoha haholo. ,25,26,27, arc stirring28 and oscillation29, electromagnetic effects during pulsed plasma arcs30,31 and other method32 have been taken .Hokela ho substrate ho sebelisa e ka ntle high-intensity ultrasound mohloli (ka 20 kHz) . The ultrasound-induced ultra-induced plasma arcs30,31 le mekhoa e meng32 li 'nile tsa nkoa. hlahisa likristale tse ncha ka cavitation.
Mosebetsing ona, re ile ra batlisisa monyetla oa ho fetola sebopeho sa lijo-thollo tsa austenitic stainless steels ka ho sonicating letamo le qhibilihisitsoeng ka maqhubu a molumo a hlahisoang ke laser e qhibilihisang ka boeona.The intensity modulation of the laser radiation incident on the light-absorbing medium results in the generation of ultrasonic wave wave, which alter the microstructure of the microstructure of the microstructure of the sLMD printer can be easily.3 Mosebetsi ona o ne o etsoa ka lipoleiti tsa tšepe tse sa hloekang tseo bokaholimo ba tsona bo neng bo pepesehetse mahlaseli a laser a matla.
Le hoja ho ultrasonic horn-based ultrasonic therapy, matla a ultrasonic a leqhubu la molumo o emeng a ajoa ho pholletsa le karolo, athe laser-induced ultrasonic intensity e tsepamisitsoe haholo haufi le moo mahlaseli a laser a kenngoa teng. khatello ea coustic e haufi le zero 'me lebelo la phatsa le na le amplitude e kholo holim'a karolo eohle e ka holimo ea karolo.Khatello ea molumo ka har'a letamo lohle le entsoeng ka ho qhibilihisoa e ke ke ea feta 0.1% ea khatello e phahameng e hlahisoang ke hlooho ea welding, hobane maqhubu a maqhubu a ultrasonic a nang le maqhubu a 20 kHz ka tšepe e sa hloekang ke \(~\sim) hangata ke \(~\sim) ho feta 0. \mongolo {mm}\).Ka hona, phello ea ultrasound ho cavitation e ka ba nyane.
Hoa lokela ho hlokomeloa hore ts'ebeliso ea mahlaseli a laser a matla-modulated ka ho toba ka laser metal deposition ke sebaka se sebetsang sa lipatlisiso35,36,37,38.
Liphello tse futhumatsang tsa ketsahalo ea mahlaseli a laser ka mokhoa o bohareng ke motheo oa hoo e batlang e le mekhoa eohle ea lisebelisoa tsa laser 39, 40, tse kang ho itšeha 41, welding, harding, drilling 42, ho hloekisa holim'a metsi, holim'a metsi, ho bentša holim'a metsi 43, joalo-joalo.
Ho lokela ho hlokomeloa hore ketso leha e le efe e sa emeng ka har'a seaplane, ho kenyeletsoa ketso ea ho tsilatsila holim'a mokhoa o monyang, o fella ka ho tsosoa ha maqhubu a acoustic ho eona ka katleho e kholo kapa e fokolang.Qalong, sepheo se seholo e ne e le ho hlasimolla ha maqhubu a maqhubu ka har'a metsi le mekhoa e sa tšoaneng ea mocheso oa mocheso oa molumo (katoloso ea mocheso, mouoane, phetoho ea molumo nakong ea phase4,97, 4, 8, 9, 9, 20). s50, 51, 52 e fana ka litlhahlobo tsa theory ea ts'ebetso ena le ts'ebeliso ea eona e sebetsang.
Litaba tsena li ile tsa buisanoa ka mor'a likopano tse fapa-fapaneng, 'me excitation ea laser ea ultrasound e na le likopo lits'ebetsong tse peli tsa indasteri ea laser technology53 le medicine54.Ka lebaka leo, ho ka nkoa hore khopolo ea motheo ea ts'ebetso eo ka eona pulsed laser light acts on an absorbing medium e thehiloe.Laser ultrasonic inspection is used for defect discovery of SLM-manufactured5 sampuli5.
Phello ea maqhubu a ts'oenyeho a hlahisoang ke laser holim'a lisebelisoa ke motheo oa laser shock peening57,58,59, e sebelisoang hape bakeng sa kalafo ea bokaholimo ba likarolo tse entsoeng ka mokhoa o eketsehileng60. Leha ho le joalo, ho matlafatsa laser ho sebetsa ka ho fetisisa ho nanosecond laser pulses le mechanically loaded surfaces (mohlala, le lera la mokelikeli)59 hobane mochine o kenyang khatello o eketsa tlhoro.
Liteko li ile tsa etsoa ho batlisisa liphello tse ka 'nang tsa e-ba teng tsa likarolo tse sa tšoaneng tsa' mele holim'a microstructure ea thepa e tiileng.Sets'oants'o se sebetsang sa setupong sa liteko se bontšoa ho Setšoantšo sa 1.A pulsed Nd:YAG solid-state laser e sebetsang ka mokhoa oa ho sebetsa ka bolokolohi (pulse duration \(\tau _L \ sim 150~\upmu \text) e sebelisitsoeng ho se nke lehlakore letoto le sebelisitsoeng le letoto la laser. Am splitter plate system.Ho ipapisitse le motsoako oa li-filters tse sa nke lehlakore, matla a pulse ho sepheo a fapana ho tloha ho \(E_L \ sim 20~\text {mJ}\) ho ea \(E_L \ sim 100~\text {mJ}\) .Lebone la laser le bonts'itsoeng ho tloha ho sekhetho sa beam le feptjoa ho ea ho photodioquita ea nako e telele, photodiodiquita ea nako e telele e fetisoa ka nako e telele ea photodiode le li-calories tsa nako e telele. ing \(1~\text {ms}\)) e sebelisetsoa ho fumana hore na ketsahalo e etsahetseng le ho bontšoa ho tloha ho sepheo, le limithara tse peli tsa matla (photodiodes tse nang le nako e khutšoanyane ea ho arabela \(<10~\text {ns}\)) ho fumana hore na ketsahalo e etsahetseng le ho bonahatsa matla a mahlo. seipone se kentsoeng sebakeng sa mohlala.Lebisa leballo holim'a sepheo u sebelisa lense (Antireflection coating at \(1.06 \upmu \text {m}\), focal length \(160~\text {mm}\)) le thekeng la sefate sebakeng se shebiloeng 60– \(100~\upmu\text {m}\).
Setšoantšo sa schematic se sebetsang sa setupong sa liteko: 1-laser;2 - lebone la laser;3-sefahla se sa nke lehlakore;4 - photodiode e lumellanang;5 - ho arola beam;6—diaphragm;7-calorimeter ea sepakapaka sa ketsahalo;8 - khalorimitha e bonts'itsoeng;9 - mitha ea matla ea beam ea ketsahalo;10 - mitha ea matla e bonts'itsoeng;11 - lense e tsepamisitseng maikutlo;12 - seipone;13 - mohlala;14 - transducer ea piezoelectric e pharaletseng;15 - 2D converter;16 - ho beha microcontroller;17 – yuniti ya kamahanyo;18 - sistimi ea ho fumana dijithale ea likanale tse ngata e nang le litekanyetso tse fapaneng tsa lisampole;19 - komporo ea hau.
Kalafo ea Ultrasonic e etsoa ka tsela e latelang.Laser e sebetsa ka mokhoa o sa lefelloeng;ka hona nako ea laser pulse ke \(\tau _L \ sim 150~\upmu \text {s}\), e nang le nako e ngata ea nako e ka bang \(1.5~\upmu \text {s } \) e' ngoe le e 'ngoe. The temporal pulse laser pulse and its spectrum consist of a low-frequency of the low-frequency and high-frequency envelope (~ frequency) mongolo {MHz}\), joalokaha ho bontšitsoe setšoantšong sa 2.- Enfelopo ea maqhubu e fana ka ho futhumatsa le ho qhibiliha ho latelang le ho fetoha mouoane ha thepa, ha karolo e phahameng ea maqhubu e fana ka li-vibrations tsa ultrasonic ka lebaka la phello ea photoacoustic.The waveform of the ultrasonic pulse generated by laser e haholo-holo e khethoa ke sebōpeho sa nako ea matla a laser pulse.E tsoa ho \(7~\text {kHz}\) ho \ (2~\text {MHz}\),' me maqhubu a bohareng ke \(~ 0.7~\text {MHz}\). Li-acoustic pulses ka lebaka la phello ea photoacoustic li ile tsa tlalehoa ho sebelisoa li-transducers tsa broadband piezoelectric tse entsoeng ka lifilimi tsa polyvinylidene fluoride. e tloaelehileng ea mokhoa oa laser oa mahala.
Kabo ea nakoana ea laser pulse intensity (a) le lebelo la molumo (b) karolong e ka morao ea lisampole, spectra (mokokotlo o moputsoa) oa laser pulse e le 'ngoe (c) le ultrasound pulse (d) e fetang 300 laser pulses (mokokotlo o mofubelu) .
Re ka khetholla ka ho hlaka likarolo tse fokolang le tse phahameng tsa phekolo ea li-acoustic tse lumellanang le enfelopo e tlaase-frequency ea laser pulse le high-frequency modulation, ka ho latellana.The wavelengths ea maqhubu a acoustic a hlahisoang ke enfelopo ea laser pulse e feta \(40 ~\text {cm}\);ka hona, phello e ka sehloohong ea likarolo tse phahameng tsa maqhubu a marang-rang a pontšo ea acoustic ho microstructure e lebeletsoe.
Mekhoa ea 'mele ho SLM e rarahane' me e etsahala ka nako e le 'ngoe ka litekanyo tse fapaneng tsa sebaka le tsa nakoana.Ka lebaka leo, mekhoa e mengata ea mekhoa e mengata e loketse ka ho fetisisa bakeng sa tlhahlobo ea theory ea SLM.Mehlala ea lipalo e lokela ho qala ka ho ba le lintho tse ngata.Mechanics le thermophysics ea multiphase medium "solid-liquid melt" e sebelisanang le khase e nang le khase e sebetsang ka mokhoa o hlakileng ka mor'a moo e hlalosoang ke khase ea inert.LM
Sekhahla sa ho futhumatsa le ho tsidifala ho fihla ho \(10^6~\text {K}/\text {s}\) /\text{ ka lebaka la mabone a lebone a sebakeng seo a nang le matla a ho fihla ho \(10^{13}~\text {W} cm}^2\).
Nako ea ho tiisa ho qhibiliha e nka pakeng tsa 1 le \(10~\text {ms}\), e leng se tlatsetsang ho tiisa ka potlako sebaka sa ho qhibiliha nakong ea ho pholile.
Ho futhumala ka potlako ha sampuli ea holim'a metsi ho fella ka ho thehoa ha khatello e phahameng ea thermoelastic ka holim'a lera.E lekaneng (ho fihlela ho 20%) karolo ea karolo ea phofo e evaporated ka matla63, e leng se etsang hore ho be le khatello e eketsehileng ea khatello holim'a metsi ka lebaka la laser ablation.Consequently, the induced strain haholo e sotha karolo ea geometry, haholo-holo haufi le litšehetso tse phahameng tsa mahlaseli a mahlaseli a mahlaseli a mahlaseli a mahlaseli a mahlaseli a motlakase. Maqhubu a tsitsipano a hasang ho tloha holim'a metsi ho ea ho substrate.E le ho fumana lintlha tse nepahetseng tsa palo mabapi le khatello ea kelello ea sebakeng seo le kabo ea khatello, ho etsoa papiso ea mesoscopic ea bothata ba deformation elastic conjugated ho mocheso le ho fetisa boima.
Li-equation tse laolang tsa mohlala li kenyelletsa (1) li-equation tse sa tsitsang tsa ho fetisa mocheso moo conductivity ea mocheso e itšetlehileng ka boemo ba mohato (powder, melt, polycrystalline) le mocheso, (2) fluctuations in elastic deformation after continuum ablation and thermoelastic expansion equation.Bothata ba boleng ba moeli bo khethoa ke maemo a liteko. x.The mass flux e hlalosoa ho ipapisitsoe le palo ea khatello ea mouoane o tletseng oa ntho e fetohang mouoane.Kamano ea khatello ea khatello ea kelello ea elastoplastic e sebelisoa moo khatello ea thermoelastic e lekanang le phapang ea mocheso.Ka matla a lebitso \(300~\text {W}\), frequency \(10^5~\\text {Hz}~e-0}(0} intermit {0~e \ 0} 0} 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 bophara ba maballo bo sebetsang.
Setšoantšo sa 3 se bonts'a liphetho tsa papiso ea linomoro tsa sebaka se qhibilihisitsoeng ho sebelisoa mohlala oa lipalo oa macroscopic. Bophara ba sebaka sa fusion ke \(200~\upmu \text {m}\) (\(100~\upmu \text { m}\) radius) le \(40~\upmu \text \ text {m}~) e bonts'a botebo ba sebaka sa {0} {0} ~ ho fapana ha nako e le {0} \ text {0}\) ho bontša botebo ba sebaka sa {0}. \) ka lebaka la boemo bo phahameng ba nako ea ho feto-fetoha ha molumo oa molumo.Litekanyetso tsa ho futhumatsa \(V_h\) le ho pholisa \(V_c\) li latela tatellano ea \(10^7\) le \(10^6~\text {K}/\text {s}\), ka ho latellana.Litekanyetso tsena li lumellana hantle le tlhahlobo ea mag(V_) ea pele ea \(V__) ho ea ka tatellano ea mag (V_) ea mag (V_)64. ho futhumala ka potlako ha lera la holim'a metsi, moo ho tsamaisa mocheso ho substrate ho sa lekaneng ho tlosa mocheso.Ka hona, ho \(t=26~\upmu \text {s}\) mocheso o holim'a metsi o phahame ho feta \(4800 ~\text {K}\) .Mouoane o matla oa thepa o ka etsa hore sebaka sa sampuli se be tlas'a khatello e feteletseng le ho ebola.
Liphetho tsa ketsiso ea linomoro tsa sebaka se qhibilihang sa laser pulse annealing ka poleiti ea sampole ea 316L. Nako ea ho tloha qalong ea sekhahla ho ea botebong ba letamo le qhibilihisitsoeng ho fihlela boleng bo phahameng ke \(180 ~\upmu\text {s}\) .The isotherm\(T = T_L = 1723~\text's the solid boundary) (K}) e lumellana le khatello ea lihlahisoa e baloang e le mosebetsi oa mocheso karolong e latelang.Ka hona, sebakeng sa marang-rang pakeng tsa li-isoline tse peli (T=T_L\) le isobars\(\sigma =\sigma _V(T)\)), mohato o tiileng o tlas'a meroalo e matla ea mechine , e ka lebisang liphetohong ho microstructure.
Phello ena e hlalositsoe ka ho eketsehileng ho Setšoantšo sa 4a, moo boemo ba khatello sebakeng se entsoeng ka ho qhibilihisoa bo reriloeng e le mosebetsi oa nako le sebaka ho tloha holimo.Ntlha ea pele, boitšoaro ba khatello bo amana le ho feto-fetoha ha matla a laser pulse e hlalositsoeng setšoantšong sa 2 ka holimo. Khatello e kholo \ text{s}\) ea hoo e ka bang \(10~\\text {MPa}~6d\c) ea sebakeng seo e ile ea hlokomeloa {MPa}~6, c" ea sebakeng seo ho neng ho hlokometsoe ka eona. khatello sebakeng sa taolo e na le litšoaneleho tse tšoanang tsa oscillation joalo ka khafetsa \(500 ~\text {kHz}\) .Sena se bolela hore maqhubu a khatello ea ultrasonic a hlahisoa ka holim'a metsi ebe a ata ka har'a substrate.
Litšobotsi tse baloang tsa sebaka sa deformation haufi le sebaka sa ho qhibiliha se bontšoa setšoantšong sa 4b. Laser ablation le thermoelastic stress li hlahisa maqhubu a elastic deformation a jalang ka har'a substrate.Joalokaha ho ka bonoa ho tloha setšoantšong, ho na le mekhahlelo e 'meli ea ho hlahisa khatello ea kelello. Nakong ea karolo ea pele ea \(t <40~\upmu \"metšoao e tšoanang le ea "MP" e tšoanang le ea MP (8) e tšoanang le ea MP (8) ho khatello ea holimo.Khatello ena e etsahala ka lebaka la ho tlosoa ha laser, 'me ha ho khatello ea thermoelastic e ileng ea hlokomeloa libakeng tsa taolo hobane sebaka sa pele se amehileng ke mocheso se ne se le senyenyane haholo.
Maemo a khatello ea maikutlo a fetotsoeng a na le tšusumetso e kholo ho sebopeho se tiileng sa mokelikeli 'me e ka' na ea e-ba mokhoa oa ho laola o laolang tsela ea ho tiisa.The boholo ba sebaka sa deformation ke 2 ho linako tse 3 tse kholo ho feta tsa sebaka sa ho qhibiliha. 300 le \(800~\upmu \text {m}\) ho itšetlehile ka nako ea hang-hang.
Ka hona, ho feto-fetoha ho rarahaneng ha pulsed laser annealing ho lebisa ho phello ea ultrasonic.Tsela ea khetho ea microstructure e fapane haeba e bapisoa le SLM ntle le ultrasonic loading. Libaka tse sa tsitsang tse sa tsitsang li lebisa ho nako ea nako ea khatello ea khatello le ho otlolla mohatong o tiileng.Ka hona, ho thehoa ha meeli e mecha ea lijo-thollo le meeli ea subgrain e ka fetoha e ka 'nang ea e-ba teng, ka lebaka leo, ho ka khoneha ho fana ka monyetla oa ho etsa joalo. etsa sebopeho sa pulse modulation-induced ultrasound-driven SLM prototype. Tabeng ena, piezoelectric inductor 26 e sebelisoang libakeng tse ling e ka qheleloa ka thōko.
(a) Khatello e le ts'ebetso ea nako, e baloang libakeng tse fapaneng ho tloha holimo 0, 20 le \(40~\upmu \text {m}\) ho ipapisitse le axis of symmetry.(b) Khatello ea Von Mises e itšetlehileng ka nako e baloang ka matrix a tiileng boholeng ba 70, 120 le \(170~\upmu) ho tloha holim'a lisampole.
Liteko li ne li etsoa ka lipoleiti tsa tšepe tse sa hloekang tsa AISI 321H tse nang le litekanyo \ (20 \ linako tse 20 \ linako tse 5 ~ \ mongolo {mm} \) . Ka mor'a ho otla ha laser ka 'ngoe, poleiti e tsamaea \(50 ~\upmu \text {m}\),' me letheka la laser beam holim'a sepheo se ka bang \ (100 ~pm ho ea holimo ho ea holimo). etsa hore ho be le ho tsosolosoa ha lintho tse entsoeng bakeng sa ho hloekisa lijo-thollo.Maemong 'ohle, sebaka se qhibilihisitsoeng se ne se le sonicated, ho itšetlehile ka karolo ea oscillatory ea mahlaseli a laser.Sena se fella ka ho fokotseha ho fetang 5 sebakeng se tloaelehileng sa lijo-thollo. Setšoantšo sa 5 se bontša kamoo microstructure ea sebaka sa laser-melted e fetohang ka palo ea lipotoloho tse latelang tsa remelting.
Subplots (a,d,g,j) le (b,e,h,k) - microstructure ea laser melted regions, subplots (c,f,i,l) - kabo ea sebaka ea lijo-thollo tse mebala-bala.Shading emela likaroloana tse sebelisoang ho compute histogram.Mebala e lumellana le libaka tsa lijo-thollo (sheba lebala la mebala ka holimo ho histogram. Li-subplots (ac) li lumellana le tšepe e sa hloekang e sa sebetsoeng, le li-subplots (df), (gi), (jl) li lumellana le 1, 3 le 5 remelts.
Kaha matla a laser pulse ha a fetohe pakeng tsa ho feta ho latelang, botebo ba sebaka se entsoeng ka ho qhibilihisoa bo tšoana.Ka hona, mocha o latelang o "koahela" ka ho feletseng "e fetileng".
Ntlafatso ea lijo-thollo e ka 'na ea bakoa ke ho pholile ka potlako ha letamo le entsoeng ka ho qhibilihisoa65.Sete e 'ngoe ea liteko e ile ea etsoa moo holim'a lipoleiti tsa tšepe tse sa hloekang (321H le 316L) li ile tsa pepeseha mahlaseli a mahlaseli a mahlaseli a mahlaseli a maqhubu a sepakapaka (setšoantšo sa 6) le vacuum (sa feiga. Nd: LAG laser ka mokhoa oa ho sebetsa ka bolokolohi. Leha ho le joalo, ho ile ha hlokomeloa mohaho o tloaelehileng oa columnar.
Microstructure ea sebaka sa laser-melted ea laser wave wave (300 W kamehla matla, 200 mm / s scan speed, AISI 321H tšepe e sa hloekang).
(a) Microstructure le (b) electron backscatter diffraction image of the laser melting zone of vacuum continuous wave laser (matla a kamehla 100 W, scanning speed 200 mm/s, AISI 316L stainless steel) \ (\ sim 2~\text {mbar }\).
Ka hona, ho bontša ka ho hlaka hore ho feto-fetoha le maemo a thata la mapheo a laser ho na le matla a ho teba le a 67. Ultrasound lisebelisoa tse fapaneng li kenyelletsa TI-6l-4v Allerases MPA} \) 69.Such maqhubu a makala a ka ba a matla ho khothaletsa setlolo sa kolunyana se nang le bongata, se sitisang sebopeho sa lijo-kholo tsa company-tse nang le 'mala oa sethala sa kabe.
Mona, re sisinya mochine o mong o ikarabellang bakeng sa phetoho ea sebopeho ka sonication e matla. Thepa feela ka mor'a hore ho tiisetsoe ho mocheso o phahameng o haufi le sebaka sa ho qhibiliha 'me o na le khatello e tlaase haholo ea chai.Maqhubu a matla a ultrasonic a ka etsa hore phallo ea polasetiki e fetole sebopeho sa lijo-thollo tsa thepa e chesang e sa tsoa tiisoa.Leha ho le joalo, data e ka tšeptjoang ea liteko ka mocheso o itšetlehileng ka mocheso oa lihlahisoa tsa lihlahisoa \~(Tsee 15Kss are available at the yield dependent \ ~(text1500} 8) .Ka hona, ho hlahloba khopolo-taba, re ile ra etsa li-molecular dynamics (MD) simulations ea sebopeho sa Fe-Cr-Ni se tšoanang le AISI 316 L tšepe e le ho hlahloba boitšoaro ba khatello ea lihlahisoa haufi le ntlha ea ho qhibiliha. tomic Model (EAM) ho tloha ho 74. MD simulations e ne e etsoa ka ho sebelisa likhoutu tsa LAMMPS 75,76.Lintlha tsa MD ketsiso li tla hatisoa libakeng tse ling.Liphetho tsa MD tsa palo ea khatello ea maikutlo e le mosebetsi oa mocheso li bontšoa setšoantšong sa 8 hammoho le lintlha tse fumanehang tsa liteko le litlhahlobo tse ling77,78,79,82,82.
Khatello ea lihlahisoa bakeng sa AISI grade 316 austenitic stainless steel and model composition against the temperature for MD simulations. Litekanyo tsa liteko ho tloha litšupisong: (a) 77, (b) 78, (c) 79, (d) 80, (e) 81.refer to.(f)82 is an empiriences stress- dependement measure during yi-winter-ineassess .Liphetho tse kholo tsa ketsiso ea MD thutong ena li hlalosoa e le \(\vartriangleleft\) bakeng sa kristale e se nang sekoli e le 'ngoe e sa feleng le \(\vartriangleright\) bakeng sa lijo-thollo tse fokolang ho nahanoa ka boholo ba lijo-thollo tse tloaelehileng ka Holo-Petch kamano Dimensions\(d = 50~\upmu \text {m}\).
Ho ka bonoa hore ho \(T> 1500 ~\text {K}\) khatello ea chai e theoha ka tlase \(40~\text {MPa}\).Ka lehlakoreng le leng, likhakanyo li bolela esale pele hore laser-generated ultrasonic amplitude feta \(40~\text {MPa}\) (bona Setšoantšo sa 4b), se lekaneng ho phalla ka har'a polasetiki ea hot.
Sebopeho sa microstructure sa 12Cr18Ni10Ti (AISI 321H) austenitic stainless steel nakong ea SLM se ile sa hlahlojoa ka liteko ho sebelisoa mohloli o rarahaneng oa pulsed laser.
Phokotso ea boholo ba lijo-thollo sebakeng se qhibilihang ka laser e fumanoe ka lebaka la ho tsoela pele ho qhibiliha ka laser ka mor'a ho feta ha 1, 3 kapa 5.
Mohlala oa macroscopic o bonts'a hore boholo bo hakantsoeng ba sebaka seo ultrasonic deformation e ka 'nang ea ama ka pele ho tiisoa ho fihla ho \(1~\text {mm}\).
Mohlala oa microscopic MD o bontša hore matla a lihlahisoa a AISI 316 austenitic stainless steel a fokotsehile haholo ho \(40 ~\text {MPa}\) haufi le ntlha ea ho qhibiliha.
Liphetho tse fumanoeng li fana ka maikutlo a mokhoa oa ho laola microstructure ea lisebelisoa tse sebelisang laser e rarahaneng ea modulated mme e ka sebetsa e le motheo oa ho theha liphetoho tse ncha tsa mokhoa oa pulsed SLM.
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