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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 tsa morao tjena. Leha ho le joalo, ho sa tsotellehe mefuta e fapaneng ya dithulaganyo tsa ho etsa tlatsetso, ho akarelletsa le khethang ho tsona 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 tiea ha letamo le amanang le letamo le phahameng le amanang le ts'ebetso e phahameng ea molten e amanang le ts'ebetso e phahameng ea molten. li-gradients, litekanyetso tse phahameng tsa ho pholisa, le ho rarahana ha lipotoloho tsa ho futhumatsa ha ho qhibiliha le ho tsosolosa thepa ea 11, e lebisang ho epitaxial lijo-thollo tsa kholo 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 vibrate 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 mohato oa mokelikeli o le monyenyane, boemo bo fetoha haholo. fields16,17,18,19,20,21,22,23,24,25,26,27, arc stirring28 and oscillation29, electromagnetic effects during pulsed plasma arcs30,31 and other ways32 have been taken .Hokela ho substrate ho sebelisa ultrasound ea ka ntle ea ultrasound high-intene (The ultrasound high-intens2). ntlafatso e bakoa ke ho eketseha ha sebaka sa subcooling ka lebaka la mocheso o fokotsehileng oa mocheso le ntlafatso ea ultrasound ho 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 sLMation ea lintho tse bonahalang e ka kopanngoa habonolo. Liteko mosebetsing ona li entsoe ka lipoleiti tsa tšepe tse sa hloekang tseo bokaholimo ba tsona bo neng bo pepesehetse mahlaseli a laser a matla.Ka hona, ka botekgeniki, kalafo ea laser holim'a metsi e etsoa. "Kalafo ea molumo oa laser".
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. karolo.Ka hona, khatello ea acoustic e haufi le zero 'me lebelo la phatsa le na le amplitude e phahameng ka ho fetisisa 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 leqhubu la maqhubu a ultrasonic le maqhubu a 20 kHz ka 20 kHz ka 20 kHz ka tšepe e sa hloekang hangata {3\sim text 0m. ka tlase ho \(\ sim 0.3 ~\text {mm}\). Ka hona, phello ea ultrasound ho cavitation e ka 'na ea e-ba nyenyane.
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 tsitsisa mochini o monyang, e fella ka ho tsosoa ha maqhubu a acoustic ho eona ka katleho e nyane kapa e fokolang.Qalong, sepheo se seholo e ne e le ho hlasimolla ha maqhubu a maqhubu ka har'a metsi le mekhoa e fapaneng ea ho hlasimolla mocheso oa molumo (katoloso ea mocheso, mouoane, phetoho ea molumo nakong ea 47, jj. 49. Li-monographs tse ngata50, 51, 52 li fana ka litlhahlobo tsa khopolo-taba ea ts'ebetso ena le lits'ebetso tsa eona tse ka khonehang.
Litaba tsena li ile tsa tšohloa hamorao likopanong 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 samples5.
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 was used of neutral) letoto la li-series tsa "laser". li-filters le tsamaiso ea poleiti ea beam splitter. Ho itšetlehile ka 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 \(E_L \ sim 100~\text {mJ}\) .Lebone la laser le bonts'itsoeng ho tloha ho beam splitter le li-simulizi tsa data tsa caloriquisi li feptjoa ho ea ho li-caloric tse peli (li-photodiodes tse nang le nako e telele ea karabelo e fetang \(1~\text {ms}\)) li 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 karabo \(<10~\text {ns}\)) ho fumana ketsahalo le ho bonahatsa matla a optical. XLP12-3S-H2-D0 le seipone sa dielectric se kentsoeng sebakeng sa mohlala. Tsepamisa leballo holim'a sepheo u sebelisa lense (Antireflection coating ho \(1.06 \upmu \text {m}\), focal length \(160~\text {mm}\)) le letheka la sefate sebakeng sa sepheo sa 000m {\~ up 00m).
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 telele ea nako e ka bang \(1.5~\upmu \text {s } \) e' ngoe le e 'ngoe. The temporal shape of laser pulse and its spectrum conist of a low-frequency mo- durations of high-frequency mo-envelope \(0.7 ~\text {MHz}\), joalo ka ha ho bonts'itsoe ho Setšoantšo 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 ea ultrasonic pulse e hlahisoang ke laser e khethoa haholo-holo ke sebōpeho sa nako ea laser pulse inten. 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 ngotsoe ho sebelisoa li-transducers tsa broadband piezoelectric tse entsoeng ka lifilimi tsa polyvinylidene fluoride. laser pulses e tloaelehile ea mokhoa oa laser o sebetsang ka bolokolohi.
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 pulse ultrasound (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 litšobotsi tse sebetsang tsa khase ea inert ka nako eo e hlalosoang ka khase ea khase ea inert. latela.
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 futhumatsa ka potlako ha sebaka sa sampuli ho etsa hore ho thehoe likhatello tse phahameng tsa thermoelastic sebakeng se ka holimo. Karolo e lekaneng (ho fihlela ho 20%) ea lesela la phofo e evaporated ka matla63, e leng se etsang hore ho be le boima bo eketsehileng ba khatello holim'a metsi ka lebaka la ho tlosoa ha laser. tlhahiso ea maqhubu a ultrasonic strain that propagate from the surface to the substrate.E le hore u fumane lintlha tse nepahetseng tsa palo mabapi le khatello ea kelello ea sebakeng seo le ho ajoa ha mathata, ho etsoa mesoscopic ketsiso 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. le evaporative flux.The mass flux e hlalosoa ho ipapisitsoe le palo ea khatello ea mouoane o tletseng oa ntho e fetohang mouoane.Kamano e sebetsang hantle ea khatello ea kelello ea elastoplastic e sebelisoa moo khatello ea thermoelastic e lekanang le phapang ea mocheso \(200~\upmu \text {m}\ ) ea bophara bo sebetsang ba maballo.
Setšoantšo sa 3 se bontša liphetho tsa papiso ea linomoro tsa sebaka se entsoeng ka ho qhibilihisoa ho sebelisoa mohlala oa lipalo oa macroscopic. Bophara ba sebaka sa fusion ke \(200~\upmu \text {m}\) (\(100~\upmu \text { m}\) radius) le \(40~\upmu \text {m}\) e bonts'a botebo ba sebaka sa mocheso ka nako e ts'oanang. \(100~\text {K}\) ka lebaka la maemo a phahameng a intermittent a pulse modulation.Ho futhumatsa \(V_h\) le ho pholisa \(V_c\) litekanyetso li ka tatellano ea \(10^7\) le \(10^6~\text {K}/\text {s}\), ka ho latellana.Tlhahlobo e ntle ea 4g pakeng tsa tatellano ea rona e ntle. \(V_h\) le \(V_c\) e fella ka ho futhumala ho feteletseng 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 holimo o phahame ho feta \(4800~\text {K}\)) .
Liphetho tsa ketsiso ea lipalo tsa sebaka sa melting ea single laser pulse annealing on 316L sample plate. Nako ho tloha qalong ea sekhahla ho ea botebong ba letamo le qhibilihisitsoeng ho fihlela boleng bo phahameng ke \(180~\upmu\text {s}\).Isotherm\(T = T_L = 1723~.Mohato o pakeng tsa mokelikeli o tiileng le iso) {K} (mehala e mosehla) e lumellana le khatello ea lihlahisoa e baloang e le mosebetsi oa mocheso karolong e latelang.Ka hona, sebakeng sa marang-rang pakeng tsa li-isoline tse peli (T=T_L\) 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 ho Setšoantšo sa 2 ka holimo. Khatello e kholo \ text{s}\) ea hoo e ka bang \(10~\\text {MPa}~6,\) e ile ea hlokomeloa {MPa}~6,\) ho feto-fetoha ha khatello ea sebaka sebakeng sa taolo ho na le litšoaneleho tse tšoanang tsa oscillation joalo ka khafetsa \(500 ~\text {kHz}\) .Sena se bolela hore maqhubu a khatello ea ultrasonic a hlahisoa holimo 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 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 \ MP Miss s} \ text {s}}, ho ea holimo ho MP (8). ho feto-fetoha ho tšoanang le khatello ea holim'a metsi.Khatello ena e etsahala ka lebaka la laser ablation, '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-metsi 'me e ka' na ea e-ba mokhoa oa ho laola o laolang tsela ea ho tiisa.Boholo ba sebaka sa deformation ke 2 ho linako tse ling tsa 3 tse kholoanyane ho feta tsa sebaka sa ho qhibiliha. bophara bo sebetsang pakeng tsa 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 fetoloa ka mokhoa o ka khonehang, ka lebaka leo, e ka fetoha thepa e ka tlase e ka sebelisoang. liqeto li fana ka monyetla oa ho theha setšoantšo sa SLM se tsamaisoang ke ultrasound se tsamaisoang ke pulse.
(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 \(170~\upmu) ho tloha holim'a lisampole.
Liteko li ile tsa etsoa ka lipoleiti tsa tšepe tse sa hloekang tsa AISI 321H tse nang le litekanyo \ ( 20 \ linako tse 20 \ linako tse 5 ~ \ mongolo {mm} \) . Ka mor'a ho otla ha laser ka 'ngoe, poleiti e tsamaea \(50 ~\upmu \text {m}\),' me thekeng ea laser beam holim'a sepheo se ka bang \(100 ~pm to beam paque) hammoho le pina e tšoanang ho etsa hore remelting ea lisebelisoa tse entsoeng bakeng sa ho hloekisa lijo-thollo. Maemong 'ohle, sebaka se entsoeng ka sekontiri se ne se le sonicated, ho itšetlehile ka karolo ea oscillatory ea mahlaseli a laser.Sena se fella ka ho fokotseha ho fetang makhetlo a 5 sebakeng se tloaelehileng sa lijo-thollo. Setšoantšo sa 5 se bontša kamoo microstructure ea sebaka sa laser-melted e fetohang ka palo ea li-remelting tse latelang.
Subplots (a,d,g,j) le (b,e,h,k) - microstructure ea laser melted regions, subplots (c,f,i,l) - kabo ea sebaka ea lijo-thollo tse mebala-bala. Shading emela likaroloana tse sebelisoang ho compute histogram.Mebala e lumellana le libaka tsa lijo-thollo (sheba lebala la mebala ka holimo ho histogram. Li-subplots (ac) li lumellana le tšepe e sa hloekang e sa sebetsoeng, le li-subplots (df), (gi), (jl) li lumellana le 1, 3 le 5 remelts.
Kaha matla a laser pulse ha a fetohe pakeng tsa ho feta ho latelang, botebo ba sebaka se entsoeng ka ho qhibilihisoa bo tšoana.Ka hona, mocha o latelang o "koahela" ka ho feletseng "e fetileng".
Ntlafatso ea lijo-thollo e ka 'na ea bakoa ke ho pholile ka potlako ha letamo le entsoeng ka ho qhibilihisoa65.Sete e 'ngoe ea liteko e ile ea etsoa moo holim'a lipoleiti tsa tšepe tse sa hloekang (321H le 316L) li ne li pepesehile mahlaseli a mahlaseli a laser a tsoelang pele moeeng (setšoantšo sa 6) le vacuum (sa feiga. liphetho tsa liteko tsa Nd: YAG laser ka mokhoa oa mahala.
Microstructure ea sebaka sa laser-melted ea laser wave e tsoelang pele (300 W kamehla matla, 200 mm / s scan speed, AISI 321H tšepe e sa hloekang).
(a) Microstructure le (b) electron backscatter diffraction image of the laser melting zone of vacuum continuous wave laser (matla a kamehla 100 W, scanning speed 200 mm/s, AISI 316L stainless steel) \ (\ sim 2~\text {mbar }\).
Ka hona, ho bontšoa ka ho hlaka hore mokhoa o rarahaneng oa ho feto-fetoha ha matla a laser pulse intensity o na le phello e kholo ho microstructure e hlahisoang.Re lumela hore phello ena ke ea mechine ka tlhaho 'me e etsahala ka lebaka la moloko oa li-ultrasonic vibrations tse jalang ho tloha holim'a metsi a qhibilihisang ka har'a sampula. ho fana ka matla a phahameng a ultrasound ka thepa e sa tšoaneng e kenyeletsang Ti-6Al-4V alloy 26 le tšepe e sa hloekang 34 sephetho sa.Mokhoa o ka khonehang o nahanoa ka tsela e latelang.Intense ultrasound e ka etsa hore acoustic cavitation, joalokaha ho bontšitsoe ka ultrafast in situ synchrotron X-ray imaging.The collapse of the the collapse of the cavitation shocks in the turnarte bubble access, \(100 ~\text {MPa}\) 69.Maqhubu a joalo a ts'oenyehileng a ka ba matla ka ho lekaneng ho khothaletsa sebopeho sa li-nuclei tse boholo bo boholo bo tiileng ka har'a maro a mangata, a sitisa sebopeho se tloaelehileng sa lijo-thollo tsa tlhahiso ea li-additives tsa layer-by-layer.
Mona, re sisinya mochine o mong o ikarabellang bakeng sa ho fetola sebopeho ka sonication e matla. Thepa feela ka mor'a hore ho tiee e le 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 mabapi le mocheso o itšetlehileng ka lihlahisoa tsa lihlahisoa \~(T150K ea khatello ea kelello e fumaneha ka 15K) (sheba Setšoantšo sa 8) .Ka hona, ho hlahloba khopolo-taba, re ile ra etsa lipapiso tsa limolek'hule (MD) tsa sebopeho sa Fe-Cr-Ni se ts'oanang le AISI 316 L tšepe e le ho hlahloba boitšoaro ba khatello ea chai haufi le ntlha ea ho qhibiliha. lipalo, re sebelisitse Embedded Atomic Model (EAM) ho tloha ho 74.MD simulations e ne e etsoa ho sebelisoa LAMMPS codes 75,76.Lintlha tsa MD simulation li tla hatisoa libakeng tse ling.Liphetho tsa MD tsa palo ea khatello ea chai e le mosebetsi oa mocheso li bontšoa ho Setšoantšo sa 8 hammoho le lintlha tse teng tsa liteko le tse ling tse hlahlobang, 802,817
Khatello ea lihlahisoa bakeng sa AISI grade 316 austenitic stainless steel and model composition against the temperature for MD simulations. Litekanyo tsa liteko tse tsoang ho litšupiso: (a) 77, (b) 78, (c) 79, (d) 80, (e) 81.refer to.(f)82 is an empirience stress-based in-imperature model during yi-imperature model of inhiture laser-assisted additive production.Liphetho tse kholo tsa MD thutong ena li hlalositsoe e le \(\vartriangleleft\) bakeng sa kristale e se nang sekoli e sa feleng le \(\vartriangleright\) bakeng sa lijo-thollo tse lekanyelitsoeng ho nahanoa ka boholo ba lijo-thollo tse tloaelehileng ka Holo-Petch kamano Dimensions\(d = 50~m\}\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, e lekaneng ho phalla ka 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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