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Indlela entsha esekelwe kwi-laser ekhethiweyo yokunyibilika ukulawula i-microstructure yeemveliso kwinkqubo yokuvelisa iphakanyisiwe.Umatshini uxhomekeke kwisizukulwana samaza aphezulu e-ultrasonic kwi-pool etyhidiweyo yi-complex intensity-modulated laser irradiation.Izifundo zovavanyo kunye nokulinganisa kwamanani kubonisa ukuba le ndlela yokulawula inokwenzeka ngokobugcisa kwaye inokusebenza ngokufanelekileyo kwi-laser yoyilo loyilo.
Imveliso eyongeziweyo (AM) yeendawo ezinokwakheka okuntsonkothileyo iye yanda kakhulu kumashumi eminyaka akutshanje. Nangona kunjalo, nangona kukho iintlobo ngeentlobo zeenkqubo zokuvelisa ezongezelelweyo, kubandakanywa ukunyibilika kwe-laser ekhethiweyo (SLM) 1,2,3, i-laser ngqo ye-metal deposition4,5,6, i-electron beam melting7,8 kunye nezinye9,10, iiNdawo zinokuba nesiphene. i-gradients, amazinga okupholisa aphezulu, kunye nobunzima bomjikelezo wokufudumeza ekunyibilikeni kunye nokunyibilika kwezinto eziphathekayo 11, okukhokelela ekukhuleni kwengqolowa ye-epitaxial kunye ne-porosity ebalulekileyo. I-12,13 ibonise ukuba kuyimfuneko ukulawula i-gradients ye-thermal, amazinga okupholisa, kunye nokubunjwa kwe-alloy, okanye ukusebenzisa ukutshatyalaliswa komzimba okongeziweyo ngamasimi angaphandle eepropati ezahlukeneyo, ezifana ne-ultrasound, ukufezekisa izakhiwo zengqolowa ezilinganayo.
Upapasho oluninzi lujongene nefuthe lonyango lwe-vibration kwinkqubo yokuqinisa kwiinkqubo eziqhelekileyo zokuphosa14,15.Nangona kunjalo, ukusebenzisa intsimi yangaphandle kwi-bulk melt ayivelisi i-microstructure yezinto ezifunwayo.Ukuba umthamo wesigaba solwelo sincinci, imeko iyatshintsha kakhulu.Kule meko, intsimi yangaphandle ichaphazela kakhulu inkqubo yokuqinisa. amasimi16,17,18,19,20,21,22,23,24,25,26,27, arc stirring28 kunye ne-oscillation29, iziphumo ze-electromagnetic ngexesha le-pulsed plasma arcs30,31 kunye nezinye iindlela32 ziye zaqwalaselwa .Qhoboshela kwi-substrate usebenzisa i-ultrasound ye-high-intens ye-ultra-incentity2 yangaphandle. ukucokiswa kubangelwa kukwanda kwendawo yokupholisa ngenxa yokuncitshiswa kweqondo lokushisa kunye nokuphuculwa kwe-ultrasound ukuvelisa iikristali ezintsha nge-cavitation.
Kulo msebenzi, siye saphanda ukuba kunokwenzeka ukuguqula ukwakheka kweenkozo ze-austenitic stainless steels ngokwenza i-sonicating pool etyhidiweyo kunye namaza omsindo aveliswa yi-melting laser ngokwayo.Ukumodareyithwa kokuqina kwesiganeko semitha ye-laser kwisiphumo sokukhanya okuphakathi kwisizukulwana samaza e-ultrasonic, aguqula i-microstructure ye-microstructure ye-radiation ye-sLMD ekhoyo inokudityaniswa lula kwi-laser ye-sLMD ekhoyo. Iimvavanyo kulo msebenzi zenziwa kwiipleyiti zensimbi ezingenasici eziye zavezwa ngamandla-modulated laser radiation.So, ngobuchwephesha, unyango lomphezulu we-laser lwenziwa.Noko ke, ukuba unyango lwe-laser lwenziwa kumphezulu womaleko ngamnye, ngexesha le-layer-by-layer build-up, iziphumo kumthamo wonke okanye kwiindawo ezikhethiweyo zomthamo ziyafezekiswa.Ngamanye amazwi, ukuba i-laser yonyango yonyango yenziwayo umaleko ngamnye we-laser. "Unyango umthamo we-laser".
Nangona kwi-ultrasonic uphondo olusekelwe kunyango lwe-ultrasonic, amandla e-ultrasonic ye-wave yesandi esimileyo isasazwa kulo lonke icandelo, ngelixa i-laser-induced intensity ye-ultrasonic igxininiswe kakhulu kufuphi nendawo apho i-laser radiation ibanjwe khona. Ngoko ke, uxinzelelo lwe-acoustic lusondele kwi-zero kwaye i-particle velocity inomlinganiselo ophezulu we-amplitude phezu kwendawo yonke ephezulu yecandelo.Uxinzelelo lwesandi ngaphakathi kwi-pool yonke etyhidiweyo ayikwazi ukudlula i-0.1% yoxinzelelo oluphezulu oluveliswa yintloko ye-welding, kuba ubude be-wave wave of ultrasonic kunye ne-frequency ye-20 kHz kwi-stainless steel , ~ ngokuqhelekileyo i-stainless steel {0m}. ngaphantsi kwe \(\ sim 0.3 ~\text {mm}\) . Ngoko ke, umphumo we-ultrasound kwi-cavitation unokuba yincinci.
Kufuneka kuqatshelwe ukuba ukusetyenziswa kwemitha ye-laser ene-intensity-modulated intestination laser metal deposition yindawo esebenzayo yophando35,36,37,38.
Iziphumo thermal isiganeko laser radiation kwi medium sisiseko phantse zonke izixhobo laser processing izinto 39, 40, ezifana nokusika 41, welding, ukuqina, ukomba 42, ukucocwa umphezulu, ingxubevange umphezulu, ukugudisa umphezulu 43, etc.materials processing technology kunye neziphumo preliminary isishwankathelo ezininzi reviews kunye monographs 5, 44, 46, 46.
Kufuneka kuqatshelwe ukuba nayiphi na intshukumo engapheliyo kwi-medium, kubandakanywa isenzo sokunyathela kwi-absorption medium, ibangela ukuvuswa kwamaza e-acoustic kuyo ngokusebenza okungaphezulu okanye ngaphantsi.Ekuqaleni, eyona nto yayigxininisekile kwi-laser excitation yamaza kumanzi kunye neendlela ezahlukeneyo zokuvuselela i-thermal yesandi (ukwandiswa kwe-thermal, u-evaporation, ukuguqulwa kwevolumu, i-contract4 ngexesha le-4 isigaba, njl njl. 49. Iimonographs ezininzi50, 51, 52 zibonelela ngocazululo lwethiyori yale nkqubo kunye nokusetyenziswa kwayo okunokwenzeka.
Le micimbi yaxoxwa emva koko kwiinkomfa ezahlukeneyo, kwaye i-laser excitation ye-ultrasound inezicelo kuzo zombini izicelo zoshishino lwe-laser technology53 kunye neyeza54.Ngoko ke, kunokuqwalaselwa ukuba ingcamango eyisiseko yenkqubo apho i-pulsed laser light acts on an absorbing medium iye yasekwa.Ukuhlolwa kwe-Laser ultrasonic kusetyenziselwa ukufumanisa i-defect ye-SLM-eyenziwe,55 iisampuli5.
Umphumo wamaza othusayo owenziwe ngelaser kwizinto sisiseko somothuko welaser peening57,58,59, ekwasetyenziselwa unyango olungaphezulu lweengxenye ezenziwe ezongezelelweyo60.Nangona kunjalo, ukomeleza ukothusa kwelaser kusebenza kakhulu kwiipulses laser nanosecond kunye neendawo ezilayishwe ngoomatshini (umz., kunye nomaleko wolwelo)59 kuba ukulayishwa koomatshini kwandisa incopho yoxinzelelo.
Iimvavanyo zenziwa ukuphanda imiphumo enokwenzeka yemimandla eyahlukeneyo ebonakalayo kwi-microstructure yezinto eziqinisiweyo.Umzobo osebenzayo wokuseta uvavanyo uboniswe kuMzobo 1.I-pulsed Nd: YAG i-solid-state laser esebenza kwimo esebenza ngokukhululekileyo (ubude be-pulse \ (\ tau _L \ sim 150 ~ \ upmu \ itekisi) isetyenziswe uchungechunge lwe-laser engathathi hlangothi. izihlungi kunye nenkqubo yeplate yeplate ye-beam.Ngokuxhomekeke kwindibaniselwano yezihluzi zoxinaniso olungathathi hlangothi, amandla e-pulse kwithagethi ahluka ukusuka \(E_L \ sim 20 ~\text {mJ}\) ukuya \(E_L \ sim 100 ~\text {mJ}\) .I-laser beam ebonakaliswe kwi-beam splitter ye-beam splitter ifakwe kwidatha ye-caloric ye-simul kunye nedatha ye-calodio ye-simuliquisi etyiswa kwi-photocometer ye-simuli (iifotodiodes ezinexesha elide lokuphendula elidlulayo \(1~\text {ms}\)) zisetyenziselwa ukumisela isiganeko ukuya kwaye kubonakaliswe kwithagethi, kunye neemitha zamandla amabini (photodiodes kunye namaxesha amafutshane okuphendula \ (<10~\text {ns}\)) ukumisela isiganeko kunye nokubonakalisa amandla okukhanya. I-XLP12-3S-H2-D0 kunye nesibuko se-dielectric esifakwe kwindawo yesampula. Gxininisa i-beam kwithagethi usebenzisa i-lens (i-Antireflection coating kwi \ (1.06 \ upmu \ text {m} \), ubude bogxininiso \ (160 ~\ text {mm}\)) kunye nesinqe se-beam kwindawo ekujoliswe kuyo 1 \\ 600m}
Umzobo weskimu esisebenzayo sokusekwa kovavanyo: 1-laser; 2-i-laser beam; 3-ifiltha yoxinaniso engathathi hlangothi; 4-i-synchronized photodiode; 5-umhlukanisi we-beam; 6-diaphragm; I-7-calorimeter ye-beam yesiganeko; I-8 - i-calorimeter ye-beam ebonakalisiweyo; I-9 - imitha yamandla yombane yesiganeko; I-10 - imitha yamandla e-beam ebonakalisiweyo; I-11 - i-lens yokugxila; I-12 - isipili; I-13 - isampuli; I-14 - i-broadband piezoelectric transducer; 15 – 2D converter; I-16 - i-microcontroller yokubeka; I-17 - iyunithi yongqamaniso; I-18 - inkqubo yokufumana idijithali ye-multi-channel enemilinganiselo eyahlukeneyo yesampuli; I-19 - ikhompyuter yakho.
Unyango lwe-Ultrasonic lwenziwa ngolu hlobo lulandelayo.I-laser isebenza kwimodi yokukhulula; ngoko ke ixesha le-laser pulse yi \(\tau _L \ sim 150 ~\upmu \text {s}\), equlathe ubuninzi bexesha elimalunga ne-(1.5 ~\upmu \ text {s} \) nganye.Imilo yethutyana ye-laser pulse kunye ne-spectrum yayo iquka i-low-frequency ye-envelope kunye ne-envelope ephakathi \ (0.7 ~ \ umbhalo {MHz} \), njengoko kubonisiwe kwi-Figure 2.- Imvulophu ephindaphindiweyo ibonelela ngokufudumeza kunye nokunyibilika okulandelayo kunye nokunyuka kwezinto eziphathekayo, ngelixa icandelo eliphezulu le-frequency libonelela ngee-vibrations ze-ultrasonic ngenxa yesiphumo se-photoacoustic. Isuka \(7~\text {kHz}\) ukuya \ (2~\text {MHz}\), kwaye i-frequency center is \(~ 0.7~\text {MHz}\) i-laser pulses ifana ne-laser yemowudi esebenza simahla.
Ukuhanjiswa kwexeshana kwe-laser pulse intensity (a) kunye nesantya sesandi (b) kumphezulu ongemva wesampulu, i-spectra (igophe elibhlowu) ye-laser pulse enye (c) kunye ne-ultrasound pulse (d) ephakathi kwama-300 laser pulses (igophe elibomvu) .
Siyakwazi ukuhlukanisa ngokucacileyo i-low-frequency kunye ne-high-frequency components yonyango lwe-acoustic ehambelana nemvulophu ye-low-frequency ye-laser pulse kunye ne-high-frequency modulation, ngokulandelanayo.Ubude be-acoustic wave wave wavely by laser pulse envelope idlula \(40 ~\text {cm}); ngoko ke, umphumo ophambili we-broadband high-frequency components of the acoustic signal kwi-microstructure kulindeleke.
Iinkqubo eziphathekayo kwi-SLM ziyinkimbinkimbi kwaye zenzeke ngexesha elifanayo kwimilinganiselo eyahlukeneyo yendawo kunye neyexeshana.Ngoko ke, iindlela ezininzi ze-multi-scale zifaneleke kakhulu kuhlalutyo lwethiyori ye-SLM.Iimodeli zezibalo kufuneka ziqale zibe yi-multi-physical.I-mechanics kunye ne-thermophysics ye-multiphase medium "i-solid-liquid melt" isebenzisana ne-belt loading esebenzayo kwi-smommal ye-smoml echazwe ngoko i-bet i-gas esebenzayo inokuthi ichazwe kwi-smoml ye-inert. iyalandela.
Amazinga okufudumeza kunye nokupholisa ukuya kuthi ga \(10^6~\text {K}/\text {s}\) /\text{ ngenxa yokukhanya kwelaser yendawo kunye noxinzelelo lwamandla ukuya kuthi ga \(10^{13}~\text {W} cm}^2\).
Umjikelo we-melting-solidification uhlala phakathi kwe-1 kunye \(10~\text {ms}\), enegalelo ekuqiniseni ngokukhawuleza kwendawo yokunyibilika ngexesha lokupholisa.
Ukufudumeza okukhawulezayo komgangatho wesampula kubangela ukubunjwa koxinzelelo oluphezulu lwe-thermoelastic kwi-surface layer.Eyaneleyo (ukuya kwi-20%) inxalenye yoluhlu lwe powder i-evaporated kakhulu63, ephumela kumthwalo ongezelelweyo woxinzelelo phezu komhlaba ekuphenduleni ukukhutshwa kwe-laser. Ukuveliswa kwamaza e-ultrasonic strain asasaza ukusuka phezulu ukuya kwi-substrate.Ukuze ufumane idatha echanekileyo yobuninzi kwixinzelelo lwengingqi kunye nokusabalalisa ukuxhatshazwa, ukulinganisa kwe-mesoscopic yengxaki ye-elastic deformation edibeneyo ekushiseni kunye nokudluliselwa kobuninzi kuyenziwa.
I-equations elawulayo yemodeli ibandakanya (1) i-equations yokudlulisa ubushushu engazinzanga apho ukuhanjiswa kwe-thermal kuxhomekeke kwimeko yesigaba (umgubo, ukunyibilika, i-polycrystalline) kunye nobushushu, (2) ukuguquguquka kwe-elastic deformation emva kokukhutshwa okuqhubekayo kunye nokulinganisa kwe-thermoelastic yokwandisa. kunye ne-evaporative flux.I-mass flux ichazwa ngokusekelwe ekubalweni koxinzelelo lwe-saturated vapor ye-evaporating material.I-elastoplastic stress-strain relationship isetyenziswa apho uxinzelelo lwe-thermoelastic lulingana nolwahlulo lobushushu.Kumandla aqhelekileyo \(300~\text {W}\), i-frequency \(10^5~}), i-frequency (10 ^ 5 ~\text) \(200~\upmu \umbhalo {m}\ ) wedayamitha esebenzayo yomqadi.
Umzobo wesi-3 ubonisa iziphumo zokulinganisa kwamanani ommandla otyhidiweyo usebenzisa imodeli yemathematika enkulu.Idayamitha yendawo yodibaniso yi \(200~\upmu \text {m}\) (\(100~\upmu \text { m}\) radius) kunye \(40~\upmu \ okubhaliweyo {m}\) kubonisa ubunzulu bexesha kunye nexesha lokulinganisa lendawo. \(100~\text {K}\) ngenxa yeqondo eliphezulu eliphakathi kokumodareyitha kwepulse.Izinga lokufudumeza \(V_h\) kunye nokupholisa \(V_c\) zingolandelelwano lwe-\(10^7\) kunye \(10^6~\text {K}/\text {s}\), ngokulandelelanayo.La maxabiso alungeleleneyo angaphambili. \(V_h\) kunye \(V_c\) kubangela ukufudumeza ngokukhawuleza komgangatho ophezulu, apho ukuhanjiswa kwe-thermal kwi-substrate akwanelanga ukususa ubushushu.Ngoko ke, kwi-(t=26~\upmu \text {s}\) iqondo lokushisa eliphezulu liphezulu njenge \(4800 ~\text {K}\)) .
Iziphumo zokulinganisa amanani zommandla wokunyibilika we-single laser pulse annealing kwi-316L yesampuli yeplate. Ixesha ukusuka ekuqaleni kwe-pulse ukuya kubunzulu be-pool etyhidiweyo ukufikelela kwixabiso eliphezulu \ ( 180 ~ \ upmu \ text {s} \ ) .I-isotherm \ (T = T_L = 1723 ~.) imele i-liquid isigaba kunye ne-isolid {K} (imigca ephuzi) ihambelana noxinzelelo lwesivuno olubalwe njengomsebenzi weqondo lokushisa kwicandelo elilandelayo.Ngoko ke, kwi-domain phakathi kwe-isolines ezimbini (i-isotherms \ (T = T_L \) kunye ne-isobars \ (\ sigma =\ sigma _V (T) \)), isigaba esiqinileyo sixhomekeke kwimithwalo enamandla yomatshini , enokuthi ibangele utshintsho kwi-microstructure.
Esi siphumo sichazwe ngakumbi kwi-Figure 4a, apho inqanaba loxinzelelo kwindawo etyhidiweyo icwangciswe njengomsebenzi wexesha kunye nomgama ukusuka kwindawo.Okokuqala, ukuziphatha koxinzelelo kuhambelana nokumodareyithwa kwe-laser pulse intensity echazwe kuMzobo 2 apha ngasentla.Uxinzelelo oluphezulu \umbhalo{s}\) malunga ne-(10 ~\text {MPa} ~ d,(i-2) yaqatshelwa. ukuguquguquka koxinzelelo lwendawo kwindawo yokulawula ineempawu ezifanayo ze-oscillation njenge-frequency of \ (500 ~\text {kHz}\) .Oku kuthetha ukuba amaza oxinzelelo lwe-ultrasonic aveliswa kumphezulu aze asasazeke kwi-substrate.
Iimpawu ezibaliweyo zendawo yokuguqulwa kufuphi nommandla wokunyibilika ziboniswe kwi-Fig. 4b. Ukuchithwa kwe-Laser kunye noxinzelelo lwe-thermoelastic kuvelisa amaza e-elastic deformation asasaza kwi-substrate.Njengoko kunokubonwa kumfanekiso, kukho izigaba ezibini zokuvelisa uxinzelelo. Ngexesha lokuqala kwesigaba \ (t <40 ~ \ upmu \ itekisi yoxinzelelo {s}}, ukuya kwi-MP (uxinzelelo lwe-s) ukumodareyitha okufana noxinzelelo lwangaphezulu.Olu xinzelelo lwenzeka ngenxa yokuchithwa kwe-laser, kwaye akukho xinzelelo lwe-thermoelastic lubonwa kwiindawo zokulawula ngenxa yokuba indawo yokuqala echaphazelekayo yokushisa yayincinci.Xa ubushushu buchithwa kwi-substrate, indawo yokulawula ivelisa uxinzelelo oluphezulu lwe-thermoelastic ngasentla \(40 ~\text {MPa}\).
Amanqanaba oxinzelelo afunyenweyo anempembelelo ebalulekileyo kwi-interface eqinile-olulwelo kwaye ingaba yindlela yokulawula elawula indlela yokuqinisa.Ubungakanani bendawo ye-deformation yi-2 ukuya ku-3 amaxesha amakhulu kunommandla wokunyibilika.Njengoko kuboniswe kuMfanekiso 3, indawo ye-isotherm encibilikayo kunye nenqanaba loxinzelelo olulingana noxinzelelo lwe-irradised yendawo kunye nomthwalo ophezulu we-laser ubonelela. idiameter esebenzayo phakathi kwe 300 kunye \(800~\upmu \text {m}\) ngokuxhomekeke kwixesha langoko nangoko.
Ngoko ke, ukumodareyitha okuyinkimbinkimbi kwe-pulsed laser annealing kukhokelela kwisiphumo se-ultrasonic.Indlela yokukhethwa kwe-microstructure iyahluka xa ithelekiswa ne-SLM ngaphandle kokulayisha i-ultrasonic.Imimandla engazinzanga ephosakeleyo ikhokelela kwimijikelezo ye-periodic yokunyanzeliswa kunye nokwelula kwisigaba esiqinileyo.Ngoko ke, ukubunjwa kwemida emitsha yeenkozo kunye nemida ye-subgrain iyahluka njengoko ibonakaliswe ngezantsi, ngoko ke iipropati ezifunyenweyo ziyakwazi ukubonakaliswa. izigqibo zinika ithuba lokuyila i-pulse modulation-induced ultrasound-driven SLM prototype.Kule meko, i-piezoelectric inductor 26 esetyenziswa kwenye indawo ingabandakanywa.
(a) Uxinzelelo njengomsebenzi wexesha, olubalwe kumgama owahlukileyo ukusuka kumphezulu 0, 20 kunye \(40~\upmu \okubhaliweyo {m}\) ecaleni kwe-axis ye-symmetry.(b) Uxinzelelo lwexesha likaVon Mises oluxhomekeke kwimatrix eqinileyo kwimigama 70, 120 kunye \(170~\upmu \\ upmu) okubhaliweyo
Iimvavanyo zenziwa kwi-AISI 321H iipleyiti zensimbi ezingenasici kunye nemilinganiselo \ (20 \ amaxesha 20 \ amaxesha 5 ~ \ umbhalo {mm} \) . Emva kwe-laser pulse nganye, i-plate ihamba \ (50 ~\upmu \ text {m}\), kunye nesinqe se-laser kwindawo ekujoliswe kuyo malunga ne-(100 ~pm ukuya kwi-upmu) kunye nomzila ofanayo ukubangela ukuxutywa kwezinto ezicwangcisiweyo zokucoca ukutya okuziinkozo.Kuzo zonke iimeko, ummandla oxutywe kunye ne-sonicated, ngokuxhomekeke kwi-oscillatory component ye-laser radiation.Oku kubangela ukunciphisa okungaphezulu kwe-5-fold in average grain area.Figure 5 ibonisa indlela i-microstructure ye-laser-melted region itshintsha kunye nenani le-remelting elandelayo (i-remelting).
Iziqendu (a,d,g,j) kunye (b,e,h,k) – microstructure of laser melted regions, subplots (c,f,i,l) - ukuhanjiswa kwendawo yeenkozo ezinemibala. I-Shading imele amasuntswana asetyenziselwa ukubala i-histogram.Imibala ihambelana nemimandla yeenkozo (jonga ibha yombala phezulu kwi-histogram. I-Subplots (ac) ihambelana nentsimbi engaxutywanga, kunye ne-subplots (df), (gi), (jl) ihambelana ne-1, 3 kunye ne-5 remelts.
Ekubeni i-laser pulse energy ayitshintshi phakathi kokudlula okulandelayo, ubunzulu bommandla otyhidiweyo bufana.Ngoko ke, umjelo olandelayo "ugubungela" ngokupheleleyo into yangaphambili.Nangona kunjalo, i-histogram ibonisa ukuba i-medium and median grain area iyancipha ngokunyuka kwenani lokupasa.Oku kungabonisa ukuba i-laser isebenza kwi-substrate kunokuba inyibilike.
Ukucocwa okuziinkozo kunokubangelwa kukupholisa ngokukhawuleza kwechibi elinyibilikisiweyo65.Enye iseti yemifuniselo yaqhutywa apho imiphezulu yeepleyiti zensimbi engenasici (321H kunye ne-316L) zavezwa kwimitha yelaser eqhubekayo emoyeni (Fig. 6) kunye ne-vacuum (Fig. 7) iziphumo zovavanyo lwe-Nd: YAG laser kwimodi esebenza ngokukhululekileyo.Nangona kunjalo, ulwakhiwo oluqhelekileyo lwekholamu lwabonwa.
I-Microstructure ye-laser-melted region ye-laser wave wave (300 W amandla angapheliyo, i-200 mm / s scan speed, i-AISI 321H insimbi engenasici).
(a) I-Microstructure kunye (b) ne-electron backscatter diffraction image of the laser melting zone of vacuum i-wave wave laser (amandla ahlala e-100 W, isivinini sokuskena i-200 mm / s, i-AISI 316L insimbi engenasici) \ (\ sim 2 ~\ text {mbar} \).
Ngoko ke, kuboniswa ngokucacileyo ukuba i-modulation eyinkimbinkimbi ye-laser pulse intensity inempembelelo ebalulekileyo kwi-microstructure. ukubonelela nge-high-intensity ultrasound kwizinto ezahlukeneyo ezibandakanya i-Ti-6Al-4V i-alloy 26 kunye nensimbi engenasici 34 isiphumo.Indlela enokwenzeka ngayo ichazwa ngolu hlobo lulandelayo.I-ultrasound enamandla ingabangela i-acoustic cavitation, njengoko kubonisiwe kwi-ultrafast in situ synchrotron X-ray imaging.Ukuwa kwe-stainless steel 34 isiphumo soxinzelelo olunokuthi lufikelele kwi-bubble bubble ngaphambili, lufikelele kwi-cavitation bubble kwi-bubble yangaphambili. \(100~\teksti {MPa}\) 69.Amaza othuso anjalo anokuba namandla ngokwaneleyo ukukhuthaza ukubunjwa kwe-nuclei yesigaba esiqinileyo esinobungakanani obubalulekileyo kulwelo oluninzi, ukuphazamisa ulwakhiwo oluqhelekileyo lwekholamu yenkozo yokwenziwa komaleko-ngamaleko okongezayo.
Apha, siphakamisa enye indlela enoxanduva lokuguqulwa kwesakhiwo nge-sonication enzulu. Izinto eziphathekayo emva nje kokuqiniswa kubushushu obuphezulu kufuphi nendawo yokunyibilika kwaye zinexinzelelo lwesivuno esiphantsi kakhulu. Amaza anamandla e-ultrasonic angabangela ukuhamba kweplastiki ukuguqula isakhiwo sengqolowa yezinto ezishushu ezisanda kuqina.Nangona kunjalo, idatha yovavanyo ethembekileyo kwiqondo lokushisa lokuxhomekeka koxinzelelo lwesivuno {1\5K ifumaneka kwi- {1} KDE ifumaneka kwi. (jonga umzobo 8) .Ngoko ke, ukuvavanya i-hypothesis, senze i-molecular dynamics (MD) ukulinganisa ukubunjwa kwe-Fe-Cr-Ni efana ne-AISI 316 L yentsimbi ukwenzela ukuvavanya ukuziphatha koxinzelelo lwesivuno kufuphi nendawo yokunyibilika.Ukubala uxinzelelo lwesivuno, sasebenzisa i-MD shear stress relaxation technique echazwe kwi-1,7tomic interion echazwe kwi-1,7,7,7,7,7. izibalo, sasebenzisa i-Embedded Atomic Model (EAM) ukusuka kwi-74.MD ukulinganisa kwenziwa ngokusebenzisa iikhowudi ze-LAMMPS 75,76.Iinkcukacha zokulinganisa i-MD ziya kupapashwa kwenye indawo.Iziphumo zokubala ze-MD zoxinzelelo lwesivuno njengomsebenzi wokushisa ziboniswa kwi-Fig. 8 kunye nedatha yovavanyo ekhoyo kunye nolunye uvavanyo, i-808,817
Uxinzelelo lwesivuno kwibakala le-AISI grade 316 i-austenitic stainless steel kunye nokwakhiwa kwemodeli ngokuchasene nobushushu bokulinganisa kwe-MD. Imilinganiselo yovavanyo evela kwiimbekiselo: (a) 77, (b) 78, (c) 79, (d) 80, (e) 81.bhekisela. i-laser-assisted additive production.Iziphumo zokulinganisa i-MD enkulu kolu phononongo zichazwa njenge \(\vartriangleleft\) yekristale engenasiphene engenasiphelo kunye \(\vartriangleright\) yeenkozo ezinomda kuthathela ingqalelo ubungakanani obuziinkozo obuqhelekileyo ngeHolo-Petch yobudlelwane Ubungakanani \(d = 50 ~m\}).
Kungabonwa ukuba \ (T> 1500 ~ \ umbhalo {K} \) isivuno soxinzelelo lwehla ngezantsi \ (40 ~ \ umbhalo {MPa} \) . Ngakolunye uhlangothi, uqikelelo luqikelele ukuba i-laser-generated ultrasonic amplitude idlula \ (40 ~ \ text {MPa} \) (jonga umzobo 4b), owaneleyo ukuhamba kwezinto eziqinileyo kwiplastiki eshushu.
Ukwakhiwa kwe-microstructure ye-12Cr18Ni10Ti (AISI 321H) i-austenitic stainless steel ngexesha le-SLM yaphandwa ngovavanyo kusetyenziswa umthombo we-laser we-pulsed intensity-modulated.
Ukunciphisa ubungakanani beenkozo kwindawo yokunyibilika kwe-laser kufunyenwe ngenxa ye-laser remelting eqhubekayo emva kokudlula kwe-1, i-3 okanye i-5.
Imodeli yeMacroscopic ibonisa ukuba ubungakanani obuqikelelweyo bommandla apho i-ultrasonic deformation inokuchaphazela ngokuqinisekileyo i-frontification front ifikelela kwi-(1~\text {mm}\).
Imodeli ye-MD ye-microscopic ibonisa ukuba amandla okuvelisa i-AISI 316 i-austenitic stainless steel iyancipha kakhulu kwi-(40 ~\ text {MPa} \) kufuphi ne-melting point.
Iziphumo ezifunyenweyo zicebisa indlela yokulawula i-microstructure yezixhobo usebenzisa i-modulated laser processing kwaye inokusebenza njengesiseko sokudala utshintsho olutsha lwe-pulsed SLM ubuchule.
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