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Wani sabon inji dangane da zaɓaɓɓen Laser narkewa don sarrafa microstructure na kayayyakin a cikin masana'antu tsari da aka proposed.The inji dogara ga ƙarni na high-intensity ultrasonic taguwar ruwa a cikin narkakkar pool ta hadaddun tsanani-modulated Laser irradiation.Gwargwadon binciken da lambobi kwaikwaya nuna cewa wannan iko inji ne fasaha mai yiwuwa ne kuma za a iya yadda ya kamata hadedde a cikin narke zane na zamani Laser.
Additive masana'antu (AM) na hadaddun-dimbin yawa sassa ya girma muhimmanci a cikin 'yan shekarun nan. Duk da haka, duk da iri-iri na ƙari masana'antu tafiyar matakai, ciki har da zabi Laser narkewa (SLM) 1,2,3, kai tsaye Laser karfe deposition4,5,6, lantarki katako melting7,8 da others9,10, da Parts iya zama m.This shi ne yafi saboda da takamaiman halaye na narkakkun, da m tafki, da m gradient da high coagulant. da sarkakiya na dumama hawan keke a cikin narkewa da remelting kayan11, wanda kai ga epitaxial hatsi girma da kuma gagarumin porosity12,13. Sakamakon ya nuna cewa , wajibi ne don sarrafa thermal gradients, sanyaya rates, da gami abun da ke ciki, ko amfani da ƙarin girgiza jiki ta hanyar waje filayen daban-daban Properties (misali, duban dan tayi) don cimma lafiya equiaxed hatsi Tsarin.
Yawancin wallafe-wallafen suna damuwa da tasirin jiyya na jiyya akan tsarin ƙarfafawa a cikin tsarin simintin al'ada na al'ada14,15.Duk da haka, yin amfani da filin waje zuwa girma narke ba ya samar da abin da ake so microstructure.If the girma na ruwa lokaci ne kananan, halin da ake ciki ya canza girma. filayen16,17,18,19,20,21,22,23,24,25,26,27, baka stirring28 da oscillation29, pulsed plasma arcs30,31 da sauran hanyoyin32 .Haɗa zuwa substrate ta yin amfani da wani waje high-innani mai tsanani duban dan tayi Madogararsa (a 20-kHz) da aka ƙarasa da duban dan tayi a hatsi. subcooling yankin saboda rage yawan zafin jiki gradient da duban dan tayi kayan haɓɓaka aiki don samar da sabon crystallites ta cavitation.
A cikin wannan aikin, mun bincika yiwuwar musanya tsarin hatsi na austenitic bakin karfe ta hanyar sonicating da narkakkar pool tare da sauti tãguwar ruwa generated da narkewa Laser kanta.The tsanani modulation na Laser radiation ya faru a kan haske-amsar matsakaici sakamakon a cikin ƙarni na ultrasonic tãguwar ruwa, wanda canza microstructure na material.This tsanani modulation a cikin data kasance gwaji na Laser Slider. an yi su a kan faranti na bakin karfe wanda aka fallasa su zuwa radiation laser mai tsanani-modulated.Saboda haka, a fasaha, ana yin maganin laser. Duk da haka, idan an yi irin wannan maganin laser a saman kowane Layer, a lokacin ginawa na Layer-by-Layer, ana samun sakamako akan dukan ƙarar ko a kan zaɓaɓɓen sassa na ƙarar.
Ganin cewa a cikin ultrasonic ƙaho na tushen ultrasonic far, da ultrasonic makamashi na ultrasonic makamashi na tsaye sauti kalaman da aka rarraba a ko'ina cikin bangaren, yayin da Laser-jawo ultrasonic tsanani ne sosai mayar da hankali a kusa da batu inda Laser radiation ne absorbed.Amfani da sonotrode a cikin wani SLM foda gado fusion inji yana da rikitarwa saboda saman saman gadon foda da aka fallasa zuwa ga laser radiation ya kamata ya kasance a tsaye.Bugu da ƙari, babu wani surface na inji. acoustic danniya ne kusa da sifili da barbashi gudu yana da matsakaicin amplitude a kan dukan saman surface na part.The sauti matsa lamba a cikin dukan narkakkar pool ba zai iya wuce 0.1% na matsakaicin matsa lamba generated da waldi shugaban, saboda da wavelength na ultrasonic tãguwar ruwa tare da mita na 20 kHz a bakin karfe ne \ (\ sim 0.3}) da kuma kasa da zurfin karfe ne \ ~ sim 0. 0.3 ~ \ rubutu {mm} \) .Saboda haka, tasirin duban dan tayi akan cavitation na iya zama karami.
Ya kamata a lura da cewa yin amfani da tsanani-modulated Laser radiation a kai tsaye Laser karfe jiba shi ne wani aiki yanki na bincike35,36,37,38.
The thermal sakamako na Laser radiation abin da ya faru a kan matsakaici shi ne tushen kusan duk Laser dabaru 39, 40 ga kayan aiki, irin su cutting41, waldi, hardening, drilling42, surface tsaftacewa, surface alloying, surface polishing43, etc.The sabuwar dabara na Laser ta da sabon aukuwa a cikin kayan sarrafa dabaru, da na farko sakamakon da aka taƙaita, 45 monographs da yawa.
Ya kamata a lura da cewa duk wani aikin da ba na tsaye ba a kan matsakaici, ciki har da lasing mataki a kan sha matsakaici, sakamakon a cikin tashin hankali na acoustic tãguwar ruwa a cikinta tare da fiye ko žasa yadda ya dace.Da farko, babban mayar da hankali shi ne a kan Laser tashin hankali na tãguwar ruwa a cikin taya da daban-daban thermal excitation hanyoyin na sauti (thermal fadada, evaporation, kwangila canji 7, lokaci 4 da dai sauransu). 49.Mutanen monographs50, 51, 52 suna ba da nazarin ka'idoji na wannan tsari da aikace-aikacen da zai yiwu.
Wadannan al'amurran da suka shafi da aka daga baya tattauna a daban-daban taro, da kuma Laser tashin hankali na duban dan tayi yana da aikace-aikace a cikin biyu masana'antu aikace-aikace na Laser technology53 da kuma medicine54.Saboda haka, shi za a iya la'akari da cewa ainihin ra'ayi na aiwatar da pulsed Laser haske ayyuka a kan wani absorbing matsakaici da aka found.Laser ultrasonic dubawa da ake amfani da lahani ganewa na SLM-kerarre samfurori55,56.
Sakamakon Laser-generated shock tãguwar ruwa a kan kayan ne tushen Laser girgiza peening57,58,59, wanda kuma aka yi amfani da surface jiyya na additively kerarre sassa60.Amma, Laser girgiza ƙarfafa ne mafi tasiri a kan nanosecond Laser bugun jini da mechanically ɗora Kwatancen saman (misali, tare da Layer na ruwa)59 saboda inji loading ƙara ganiya matsa lamba.
An gudanar da gwaje-gwaje don bincika yiwuwar tasirin filayen jiki daban-daban akan microstructure na kayan aiki masu ƙarfi. An nuna zane mai aiki na saitin gwaji a cikin Hoto 1. A pulsed Nd: YAG m-jihar Laser aiki a cikin free-gudun yanayin (pulse duration \ (\ tau _L \ sim 150 ~ upmu \ rubutu {s} \ ) an yi amfani da tsaka tsaki na Laser. da katako splitter farantin tsarin.Ya danganta da hade da tsaka tsaki yawa tace, da bugun jini makamashi a kan manufa dabam daga \ (E_L \ sim 20 ~ \ rubutu {mJ} \) zuwa \ (E_L \ sim 100 ~\ rubutu {mJ} \) .A Laser katako nuna daga katako splitter ne ciyar da biyu lokaci guda data, da kuma photodiode caquimeter data. (photodiodes tare da dogon amsa lokacin da ya wuce \(1 ~\ rubutu {ms}\)) ana amfani da su domin sanin abin da ya faru zuwa da kuma nuna daga manufa, da kuma biyu ikon mita (photodiodes tare da gajeren amsa lokuta \ (<10 ~\ rubutu {ns}\)) don sanin abin da ya faru da kuma nuna ikon gani. XLP12-3S-H2-D0 da madubi dielectric da aka ɗora a wurin samfurin.Maida hankali ga katako a kan manufa ta amfani da ruwan tabarau (Antireflection shafi a \ (1.06 \ upmu \ rubutu {m} \), tsayi mai tsayi \ (160 ~\rubutu {mm} \)) da katakon katako a wurin da aka yi niyya (160)
Zane-zane na aiki na saitin gwaji: 1-laser; 2 - Laser katako; 3-tsatsa mai yawa tace; 4 - photodiode da aka daidaita; 5 - mai raba katako; 6- diaphragm; 7 - calorimeter na abin da ya faru; 8 - calorimeter na katako mai haske; 9- Mitar wutar lantarki da ya faru; 10 - mitar wutar lantarki mai nunawa; 11 - ruwan tabarau mai mayar da hankali; 12 - madubi; 13 - samfurin; 14 - mai watsa shirye-shiryen piezoelectric mai watsa shirye-shirye; 15 - 2D mai canzawa; 16 - sanya microcontroller; 17 - naúrar aiki tare; 18 - Multi-tashar dijital saye tsarin tare da daban-daban samfurin rates; 19 – kwamfuta ta sirri.
Ana gudanar da magani na ultrasonic kamar haka. Laser yana aiki a cikin yanayin gudana kyauta; saboda haka da duration na Laser bugun jini ne \ (\ tau _L \ sim 150 ~ \ upmu \ rubutu {s} \ ), wanda ya ƙunshi mahara durations na kimanin \ (1.5 ~ \ upmu \ rubutu {s } \) kowane. The temporal siffar Laser bugun jini da kuma bakan kunshi wani low-mita ambulaf da modulation game da - (mita = 7). {MHz} \), kamar yadda aka nuna a cikin Hoto 2.- Ambulan mitar yana samar da dumama da narkewa mai zuwa da kuma evaporation na kayan, yayin da babban ɓangaren mita yana samar da vibrations ultrasonic saboda tasirin photoacoustic.The waveform na ultrasonic bugun jini generated da Laser aka yafi ƙaddara da lokaci siffar da Laser bugun jini tsanani. Ya fito ne daga \ (7 ~\ rubutu {kHz} \) zuwa \ (2 ~ \ rubutu {MHz} \), kuma mitar cibiyar shine \ (~ 0.7 ~\ rubutu {MHz} \) . An yi rikodin bugun jini saboda tasirin hoto ta hanyar amfani da transducers na broadband piezoelectric transducers da aka yi da polyvinylidene fluoride fina-finai. Ya kamata a yi rikodin rikodi na siffa spectrum. Laser bugun jini yana kama da na'urar laser mai gudana kyauta.
Rarraba na ɗan lokaci na ƙarfin bugun bugun laser (a) da saurin sauti a saman baya na samfurin (b), nau'ikan bugun jini na laser (c) da bugun jini na ultrasonic (d) sun daidaita sama da 300 bugun bugun laser (ja mai lanƙwasa) don bugun bugun laser guda ɗaya (launi shuɗi) .
Za mu iya bayyana a fili bambance-bambancen ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙananan ƙwayoyin jiyya da suka dace da ƙananan ambulaf na bugun jini na Laser da gyare-gyare mai mahimmanci, bi da bi. sabili da haka, ana sa ran babban tasirin babban mitar watsa shirye-shirye na siginar sauti akan microstructure.
Hanyoyin jiki a cikin SLM suna da rikitarwa kuma suna faruwa a lokaci guda a kan ma'auni daban-daban na sararin samaniya da na lokaci.Saboda haka, hanyoyi masu yawa sun fi dacewa da nazarin ka'idar SLM.Mathematical model ya kamata da farko ya zama multi-physical.The makanikai da thermophysics na multiphase matsakaici "m-ruwa narkewa" hulda da wani inert iskar gas halaye na iya zama tasiri na SLM halaye.
Adadin dumama da sanyaya har zuwa \(10^6~\rubutu {K}/\rubutu {s}\) /\rubutu{saboda gurɓataccen iska da iska mai ƙarfi da ƙarfin wuta har zuwa \(10^{13}~\rubutu {W} cm}^2\).
Zagayowar narkewa-ƙarfafa yana wanzuwa tsakanin 1 da \(10~\rubutu {ms}\), wanda ke ba da gudummawa ga saurin ƙarfafa yankin narkewa yayin sanyaya.
Rapid dumama na samfurin surface sakamakon a cikin samuwar high thermoelastic danniya a cikin surface Layer.Ya isa (har zuwa 20%) rabo na foda Layer ne karfi da evaporated63, wanda results a cikin wani ƙarin matsa lamba load a kan surface a mayar da martani ga Laser ablation.Consequently, da ja iri muhimmanci karkatar da parti, musamman kusa da goyon bayan da bakin ciki tsarin a cikin Laser sakamakon a cikin bakin ciki structural ratings. raƙuman raƙuman ruwa waɗanda ke yaduwa daga ƙasa zuwa ƙasa.Domin samun cikakkun bayanai na ƙididdigewa game da damuwa na gida da rarraba iri, ana yin simintin mesoscopic na matsalar nakasar nakasa da ke hade da zafi da canja wurin taro.
Ƙididdigar mulki na ƙirar sun haɗa da (1) ma'auni na canja wurin zafi mara kyau inda zafin zafin jiki ya dogara da yanayin yanayi (foda, narke, polycrystalline) da zafin jiki, (2) sauye-sauye a cikin nakasar nakasa bayan ci gaba da ablation na haɓakawa da haɓakar haɓakar thermoelastic. Matsalar ƙimar iyaka ta ƙaddara ta hanyar yanayin gwaji. The modulated a kan yanayin zafi mai sanyi yana ƙayyade yanayin zafi mai zafi. Flux.An bayyana ma'auni mai yawa bisa ƙididdige ma'auni na madaidaicin tururi na kayan da aka kwashe.An yi amfani da dangantaka ta elastoplastic danniya-matsala inda zafin thermoelastic ya yi daidai da bambancin zafin jiki.Don ikon maras kyau \ (300 ~ rubutu {W}\), mitar \ (10 ​​^ 5 ~ \ rubutu {~ m \ Hz} \ ), matsakaicin matsakaici \ 2000 ℃ \ 300 ℃ \ Hz} \ , 100000 . {m}\ ) na ingantaccen diamita na katako.
Hoto na 3 yana nuna sakamakon simintin lambobi na yankin narkakkar ta amfani da samfurin lissafi na macroscopic.The diamita na fusion zone ne \ (200~\upmu \ rubutu {m} \) (\ (100~\ upmu \ rubutu {m} \) radius) da kuma \ (40 ~ \ upmu \ rubutu {m} \) da kuma \ (40 ~ upmu \ rubutu {m} \) na gida yana nuna zurfin sakamakon. \(100~\text {K}\) saboda high intermittent factor na bugun jini modulation.The dumama \ (V_h \) da sanyaya \ (V_c \) rates ne a kan tsari na \ (10 ​​^ 7 \) da \ (10 ​​^ 6 ~\ rubutu {K} / \ rubutu {s} \), bi da bi. Waɗannan kyawawan oda na mu na baya da ƙima a cikin bincike da darajar. \ (V_h \) da \ (V_c \) yana haifar da saurin zafi na saman Layer, inda zafin zafin jiki zuwa ga substrate bai isa ba don cire zafi. Saboda haka, a \ (t=26 ~ \ upmu \ rubutu {s} \) yanayin zafin jiki ya kai kololuwa kamar yadda \ (4800 ~ rubutu rubutu {K}\) zai iya haifar da matsi mai ƙarfi don fitar da matsi.
Sakamakon kwaikwaiyo na lambobi na yankin narkewa na ƙwayar bugun jini guda ɗaya a kan 316L samfurin samfurin.Lokacin daga farkon bugun jini zuwa zurfin tafkin narkakkar da ya kai matsakaicin darajar shine \ (180 ~ \ upmu \ rubutu {s} \) . The isotherm \ (T = T_L = 1723 ~\ rubutu tsakanin ruwa da m lokaci). (layin rawaya) sun dace da ƙimar yawan amfanin ƙasa da aka ƙididdige su azaman yanayin zafin jiki a cikin sashe na gaba.Saboda haka, a cikin yanki tsakanin isolines guda biyu (isotherms \ (T = T_L \) da isobars \ (\ sigma = \ sigma _V (T) \)) ), ƙaƙƙarfan lokaci yana ƙarƙashin nauyin kayan aiki mai ƙarfi , wanda zai iya haifar da canje-canje a cikin microstructure.
An kara bayanin wannan tasirin a cikin Hoto 4a, inda aka tsara matakin matsa lamba a cikin yankin narkakkar a matsayin aiki na lokaci da nisa daga saman. Na farko, yanayin matsa lamba yana da alaƙa da daidaitawar ƙarfin bugun jini na laser da aka kwatanta a cikin Hoto na 2 a sama. Matsakaicin matsa lamba \ rubutu {s} \) na game da \ (10 ​​~\ rubutu {MPa} \) an lura da shi a game da \ (10 ​​~\ rubutu {MPa} \) a game da \ (t) . matsa lamba na gida a wurin sarrafawa yana da halayen oscillation iri ɗaya kamar mita na \ (500 ~\ rubutu {kHz} \) . Wannan yana nufin cewa ana haifar da raƙuman ruwa na ultrasonic a farfajiya sannan kuma ya yada cikin substrate.
Abubuwan da aka ƙididdigewa na yankin nakasar da ke kusa da yankin narkewa suna nunawa a cikin hoto 4b. Laser ablation da thermoelastic stress suna haifar da raƙuman ruwa na nakasa wanda ke yadawa a cikin substrate. Kamar yadda za'a iya gani daga adadi, akwai matakai guda biyu na ƙaddamar da damuwa. A lokacin farkon lokaci na \ (t <40 ~ upmu \ rubutu {s}\), da {8 MP modulation} , da {8 modulation. kama da matsa lamba na sama. Wannan damuwa yana faruwa ne saboda ablation na laser, kuma ba a lura da damuwa na thermoelastic a cikin wuraren sarrafawa ba saboda yanayin zafi na farko ya kasance da ƙananan ƙananan. Lokacin da zafi ya ɓace a cikin ma'auni, ma'anar sarrafawa yana haifar da matsananciyar thermoelastic a sama da \ (40 ~ \ rubutu {MPa} \).
Matsakaicin matakan da aka daidaita da aka samu suna da tasiri mai mahimmanci akan ma'aunin ruwa mai ƙarfi kuma yana iya zama tsarin sarrafawa wanda ke tafiyar da hanyar ƙarfafawa. Girman yankin nakasar shine 2 zuwa 3 sau girma fiye da na yankin narkewa. Kamar yadda aka nuna a cikin Hoto 3, wurin da ke narkewa da isotherm mai narkewa da kuma matakin damuwa daidai da yawan yawan amfanin ƙasa ana kwatanta. \(800~\upmu \rubutu {m}\) ya danganta da lokacin nan take.
Saboda haka, da hadaddun daidaitawa na pulsed Laser annealing take kaiwa zuwa ultrasonic sakamako.The microstructure selection hanya ne daban-daban idan idan aka kwatanta da SLM ba tare da ultrasonic loading.Deformed m yankunan kai ga lokaci-lokaci hawan keke na matsawa da mikewa a cikin m phase.Saboda haka, samuwar sabon hatsi iyakoki da subgrain iyakoki zama m kamar yadda aka nuna a kasa Properties, da aka nuna a kasa Properties. Ƙarshe suna ba da damar yin ƙira na ƙirar ƙirar bugun jini-induced samfurin SLM mai amfani da duban dan tayi.
(a) Matsi a matsayin aikin lokaci, ƙididdigewa a nisa daban-daban daga saman 0, 20 da \ (40 ~\upmu \ rubutu {m} \) tare da axis na daidaitawa.
An yi gwaje-gwaje akan faranti na bakin karfe na AISI 321H tare da ma'auni \ (20 \ sau 20 \ sau 5 ~ \ rubutu {mm} \ ). da aka yi tare da wannan waƙa don haifar da remelting na kayan da aka sarrafa don gyaran hatsi.A duk lokuta, yankin remelted ya kasance sonicated, dangane da oscillatory bangaren na Laser radiation.This results a cikin fiye da 5-ninka rage a cikin talakawan hatsi yankin.Hoto 5 nuna yadda microstructure na Laser-narke yankin canje-canje tare da adadin m sake zagayowar.
Matsakaicin ra'ayi (a, d, g, j) da (b,e,h,k) - microstructure na yankuna na Laser narke, raƙuman ruwa (c, f, i,l) - rarraba yanki na hatsi masu launi. Shading yana wakiltar barbashi da aka yi amfani da su don ƙididdige histogram. Launuka sun dace da yankunan hatsi (duba sandar launi a saman tarihin tarihin. Subplots (ac) yayi daidai da bakin karfe da ba a kula da shi ba, kuma subplots (df), (gi), (jl) ya dace da 1, 3 da 5 remelts.
Tun da makamashin bugun jini na laser ba ya canzawa tsakanin wucewar da ke gaba, zurfin yankin narkakkar daidai yake. Saboda haka, tashar ta gaba ta gaba daya "ya rufe" na baya. Duk da haka, histogram ya nuna cewa ma'ana da tsaka-tsakin hatsi suna raguwa tare da karuwar adadin wucewa. Wannan yana iya nuna cewa laser yana aiki a kan substrate maimakon narke.
Ana iya haifar da tsaftacewar hatsi ta hanyar saurin sanyaya na narkakken pool65. Wani saitin gwaje-gwajen da aka gudanar a cikin abin da saman na bakin karfe faranti (321H da 316L) aka fallasa zuwa ci gaba da kalaman Laser radiation a cikin yanayi (Fig. 6) da kuma injin (Fig. 7) Matsakaicin ikon Laser (300 W da girmamawa 100 W), sakamakon gwajin gwaji na kusa da 100 W. Nd:YAG Laser a cikin yanayin gudana kyauta.Duk da haka, an lura da tsarin ginshiƙi na yau da kullun.
Microstructure na Laser-narke yankin na ci gaba da igiyar Laser (300 W m iko, 200 mm / s scan gudun, AISI 321H bakin karfe).
(a) Microstructure da (b) electron backscatter diffraction hotuna na Laser-narke yankin a cikin injin daskarewa tare da ci gaba da kalaman Laser (100 W m iko, 200 mm / s scan gudun, AISI 316L bakin karfe) \ (\ SIM 2 ~ \ rubutu {mbar} \).
Saboda haka, an nuna a fili cewa hadaddun daidaitawa na Laser bugun jini tsanani yana da wani gagarumin tasiri a kan sakamakon microstructure.We yi imani da cewa wannan sakamako ne na inji a cikin yanayi da kuma faruwa saboda ƙarni na ultrasonic vibrations propagating daga irradiated surface na narke zurfi cikin sample.Similar sakamakon da aka samu a 13, 26, 34, 66, 67 da transduce transduce transduce transduce transducer ta hanyar yin amfani da waje transducer piezon piezon. daban-daban kayan ciki har da Ti-6Al-4V gami 26 da bakin karfe 34 sakamakon. The yiwu inji ne speculated kamar haka.M duban dan tayi na iya haifar da acoustic cavitation, kamar yadda aka nuna a cikin ultrafast a wurin synchrotron X-ray imaging.The rushewar cavitation kumfa bi da bi ya haifar da girgiza taguwar ruwa a cikin moltens, gaban \ 100es abin da ya kai ga matsa lamba ~ . {MPa}\) 69. Irin wannan girgizar raƙuman ruwa na iya zama mai ƙarfi don haɓaka samuwar ƙaƙƙarfan ƙaƙƙarfan ƙaƙƙarfan tsakiya a cikin ruwa mai yawa, yana rushe tsarin hatsi na al'ada na masana'anta na Layer-by-Layer ƙari.
Anan, muna ba da shawarar wani inji da ke da alhakin gyare-gyaren tsarin ta hanyar sonication mai tsanani. Nan da nan bayan ƙarfafawa, kayan yana a babban zafin jiki kusa da wurin narkewa kuma yana da ƙananan ƙananan yawan amfanin ƙasa.Intense ultrasonic taguwar ruwa na iya haifar da filastik ya kwarara don canza tsarin hatsi na zafi, kawai kayan da aka ƙera. Duk da haka, bayanan gwaji masu dogara akan yanayin zafin jiki na dogara da yawan zafin jiki na damuwa suna samuwa a \ (T Figure 5) 8) .Saboda haka, don gwada wannan hasashe, mun yi gyare-gyaren kwayoyin halitta (MD) na Fe-Cr-Ni abun da ke ciki kamar AISI 316 L karfe don kimanta halin da ake ciki na damuwa a kusa da wurin narkewa. Don ƙididdige yawan damuwa na yawan amfanin ƙasa, mun yi amfani da fasaha na kwantar da hankali na MD daki-daki a cikin 70, 71, 72, 73 da aka yi amfani da shi don lissafin hulɗar da aka yi amfani da shi don yin hulɗar E. An yi samfurin (EAM) daga 74.MD simulations ta amfani da lambobin LAMMPS 75,76. Za a buga cikakkun bayanai game da simulations MD a wani wuri. Ana nuna sakamakon lissafin MD na yawan damuwa a matsayin aikin zafin jiki a cikin hoto 8 tare da samuwan bayanan gwaji da sauran kimantawa77,78,79,80,81,82.
Samar da danniya don AISI aji 316 austenitic bakin karfe da samfurin abun da ke ciki tare da zafin jiki don simulations MD.Ma'auni na gwaji daga nassoshi: (a) 77, (b) 78, (c) 79, (d) 80, (e) 81. koma zuwa. ƙari masana'antu.Sakamako na manyan sikelin MD simulations a cikin wannan binciken ana nuna su a matsayin \ (\ vartriangleleft \) don rashin lahani marar iyaka marar iyaka da kuma \ (\ vartriangleright \) don iyakacin hatsi la'akari da matsakaicin girman hatsi ta hanyar Hall-Petch dangantaka Dimensions \ (d = 50 ~ \ upmu \ rubutu).
Ana iya ganin cewa a \ (T> 1500 ~\ rubutu {K} \) yawan yawan amfanin ƙasa yana raguwa a ƙasa \ (40 ~\ rubutu {MPa} \) . A gefe guda, ƙididdiga sun yi la'akari da cewa hasken ultrasonic da aka haifar da Laser ya wuce \ (40 ~\ rubutu {MPa} \) (duba siffa 4b), wanda ya isa ya haifar da ingantaccen filastik.
Samuwar microstructure na 12Cr18Ni10Ti (AISI 321H) bakin karfe austenitic a lokacin SLM an bincika ta hanyar gwaji ta amfani da madaidaicin ƙarfin-modulated tushen Laser.
An sami raguwar girman hatsi a yankin narkewar Laser saboda ci gaba da sake narkewar Laser bayan wucewar 1, 3 ko 5.
Macroscopic yin tallan kayan kawa ya nuna cewa kiyasin girman yankin inda nakasar ultrasonic na iya tasiri ga ingantaccen gaba mai ƙarfi har zuwa \(1~\rubutu {mm}\).
Ƙimar MD mai ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun kayan aiki na AISI 316 austenitic bakin karfe yana raguwa sosai zuwa \ (40 ~ \ rubutu {MPa} \) kusa da wurin narkewa.
Sakamakon da aka samu ya ba da shawarar wata hanya don sarrafa microstructure na kayan ta amfani da hadaddun sarrafa Laser mai daidaitawa kuma zai iya zama tushen don ƙirƙirar sabbin gyare-gyare na dabarar SLM mai pulsed.
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