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A na-atụ aro usoro ọhụrụ dabere na agbaze laser nhọrọ iji chịkwaa microstructure nke ngwaahịa na usoro nrụpụta. Usoro ahụ na-adabere na ọgbọ nke ebili mmiri ultrasonic dị elu na ọdọ mmiri a wụrụ awụ site na mgbagwoju anya ike-modulated laser irradiation.Nnwale nyocha na ọnụọgụ ọnụọgụ na-egosi na usoro nchịkwa a nwere ike ịrụ ọrụ nke ọma ma nwee ike ịmekọrịta ya nke ọma n'ime nhazi laser nke oge a.
Mgbakwunye n'ichepụta (AM) nke mgbagwoju ekara akụkụ etowo budata na-adịbeghị anya ọtụtụ iri afọ. Otú ọ dị, n'agbanyeghị dịgasị iche iche nke mmako n'ichepụta Filiks, gụnyere nhọrọ laser agbaze (SLM) 1,2,3, kpọmkwem laser metal deposition4,5,6, electron doo melting7,8 na others9,10, na Parts nwere ike ịbụ ntụpọ.This bụ tumadi n'ihi na kpọmkwem e ji mara nke ndị na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na nnukwu ọdọ mmiri na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-ekpo ọkụ na-eme ka ọkpụkpụ dị elu na-eme ka ọkpụkpụ dị elu na-eme ka ọ dị elu. cycles na agbaze na agbaze ihe11, nke na-eduga na uto ọka epitaxial na nnukwu porosity12,13.Nsonaazụ gosiri na , ọ dị mkpa ijikwa thermal gradients, jụrụ ọnụego, na alloy mejupụtara, ma ọ bụ tinye mgbakwunye anụ ahụ ujo site mpụga ubi nke dị iche iche Njirimara (eg, ultrasound) iji nweta ezi equiaxed ọka owuwu.
Ọtụtụ akwụkwọ na-emetụta mmetụta nke ọgwụgwọ vibration na usoro siri ike na usoro nkedo omenala14,15. Otú ọ dị, itinye ebe dịpụrụ adịpụ na nnukwu agbaze anaghị emepụta microstructure1 ihe a chọrọ. Ọ bụrụ na olu nke mmiri mmiri ahụ dị ntakịrị, ọnọdụ ahụ na-agbanwe n'ụzọ dị ịrịba ama. N'okwu a, ebe dịpụrụ adịpụ n'ụzọ dị ịrịba ama na-emetụta usoro siri ike.Electromagnetic,co,2 atụlewo n'oge ubi1 siri ike18. 22,23,24,25,26,27, arc stirring28 na oscillation29, pulsed plasma arcs30,31 na ndị ọzọ method32 .Attach na mkpụrụ iji mpụga elu-osisi ultrasound isi iyi (na 20 kHz) .The ultrasound-induced ntụ ntụ ntụ ntụ na-ekwu na ụbara ihe mejupụtara nke subvilite ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ ntụ. .
N'ime ọrụ a, anyị nyochara ohere nke ịgbanwe ọka Ọdịdị nke austenitic igwe anaghị agba nchara site sonicating ọdọ mmiri a wụrụ awụ na ụda ebili mmiri eme site na-agbaze laser n'onwe ya.The ike modulation nke laser radieshon mere na ìhè-absorbing ọkara pụta na ọgbọ nke ultrasonic ebili mmiri, nke na-agbanwe microstructure nke material.This ike ike modulation na-adị mfe 3 n'ime laser na-ebi akwụkwọ na-enweghị ike ịrụ ọrụ n'ime laser. efere ígwè nke elu ya na-ekpughere ike ọkụ-modulated laser radiation. Ya mere, na nkà na ụzụ, a na-eme ọgwụgwọ laser n'elu. Otú ọ dị, ọ bụrụ na a na-eme ọgwụgwọ laser dị otú ahụ n'elu oyi akwa ọ bụla, n'oge oyi akwa oyi akwa, a na-enweta mmetụta na olu dum ma ọ bụ na akụkụ ndị a họọrọ nke olu ahụ.
Ebe na ultrasonic mpi dabeere ultrasonic ọgwụgwọ, na ultrasonic ike nke na-eguzo ụda na-efegharị na-ekesa n'ime akụrụngwa, mgbe laser-induced ultrasonic intensity na-etinye uche nke ukwuu n'akụkụ ebe laser radieshon na-etinye obi. Iji sonotrode na SLM ntụ ntụ bed fusion igwe na-agbagwoju anya n'ihi na elu elu nke uzuzu bed kpughere na laser radieshon kwesịrị ịnọgide na-eguzosi ike n'ihe.Na mgbakwunye, ọ dịghị ihe na-arụ ọrụ na-arụ ọrụ n'elu. efu na urughuru ngwa ngwa nwere a kacha njupụta n'elu dum n'elu elu nke akụkụ. The ụda mgbali n'ime dum gbazee ọdọ mmiri enweghị ike gafere 0.1% nke kacha nsogbu eme site ịgbado ọkụ isi, n'ihi na wavelength nke ultrasonic ebili mmiri na ugboro nke 20 kHz na igwe anaghị agba nchara bụ \ (\ SIM 0.3 ~ \ ederede \ (\ SIM 0.3 ~ \ ederede \ (\mm 0.3 ~ 0) na-abụkarị ihe omimi {m}). Ya mere, mmetụta nke ultrasound na cavitation nwere ike ịbụ obere.
Ekwesiri iburu n'uche na iji radieshon nke siri ike megharia n'ime ntinye igwe eji eme ihe n'uzo di nkpa bu ebe nyocha35,36,37,38.
The thermal mmetụta nke laser radieshon mere na-ajụ bụ ndabere maka fọrọ nke nta niile laser usoro 39, 40 maka ihe nhazi, dị ka cutting41, ịgbado ọkụ, hardening, drilling42, elu ihicha, elu alloying, elu polishing43, etc.The mepụtara nke laser kpaliri ọhụrụ tope na ihe nhazi usoro, na mbido pụta e reviews na 45 monographed na ọtụtụ.4.
Ọ ga-kwuru na ihe ọ bụla na-abụghị ada ada edinam na-ajụ, gụnyere lasing edinam na absorbing ọkara, pụta na excitation nke acoustic ebili mmiri na ya na ihe ma ọ bụ na-erughị efficiency.Na mbụ, isi na-elekwasị anya na laser excitation nke ebili mmiri na mmiri mmiri na dị iche iche thermal excitation usoro nke ụda ( thermal mgbasa, evaporation, 4 mgbanwe mgbanwe n'oge 4 N'oge 4 N'oge Ntugharị 4 N'oge okpomọkụ, evaporation, Nkwekọrịta 4 monograph, wdg). s50, 51, 52 na-enye nyocha usoro ọmụmụ nke usoro a na ngwa ndị nwere ike ime.
Okwu ndị a e mesịrị atụle na dị iche iche ogbako, na laser excitation nke ultrasound nwere ngwa na ma ulo oru ngwa nke laser technology53 na medicine54.Ya mere, ọ nwere ike na-ewere na isi echiche nke usoro nke pulsed laser ìhè-eme ihe na-amịkọrọ usoro e guzobere.Laser ultrasonic nnyocha na-eji maka ntụpọ nchọpụta nke SLM-mepụtara samples55,56.
Mmetụta nke laser-emepụta ujo ebili mmiri na ihe bụ ndabere nke laser ujo peening57,58,59, nke a na-eji maka elu ọgwụgwọ nke additively arụpụtara parts60. Otú ọ dị, laser ujo ike kasị dị irè na nanosecond laser pulses na mechanically loaded na-ebupụta (eg, na a oyi akwa nke mmiri mmiri)59 n'ihi na n'ibu loading enwekwu elu mgbali.
A na-eduzi ule iji nyochaa mmetụta dị iche iche nke anụ ahụ dị iche iche na microstructure nke ihe ndị siri ike. E gosipụtara eserese ọrụ nke nhazi nnwale ahụ na Figure 1. A pulsed Nd: YAG solid-state laser arụ ọrụ na free-agba ọsọ mode (pulse duration \ (\ tau _L \ sim 150 ~ upmu \ ederede {s} \ ) na-eji laser na-anọpụ iche. ter efere usoro. Dabere na Nchikota na-anọpụ iche njupụta nzacha, na usu ume na lekwasịrị ịdị iche iche si \ (E_L \ sim 20 ~\ ederede {mJ} \) na \ (E_L \ SIM 100 ~\ ederede {mJ} \) .The laser doo egosipụta site na doo splitter na-nri na a photodiode a ogologo oge na photodiode na-eme ka ogologo oge photodiode na abụọ photodiode. \ (1 ~\ ederede {ms} \)) na-eji iji chọpụta ihe merenụ na-egosipụta site na lekwasịrị anya, na abụọ ike mita (photodiodes na obere nzaghachi oge \ (<10 ~\ ederede {ns}\)) iji chọpụta ihe merenụ na egosipụta ike anya. na ebe nlele. Lekwasị anya n'osisi ahụ n'elu ihe mgbaru ọsọ site na iji oghere (Mkpuchi Antireflection na \ (1.06 \ upmu \ ederede {m} \), ogologo focal \ (160~\text {mm})) na n'úkwù n'elu ebumnuche 60- \ (100~\upmu\text {m}\).
Eserese schematic na-arụ ọrụ nke nhazi nnwale: 1 — laser;2 - ọkụ laser;3-anọpụ iche njupụta nyo;4 - photodiode mekọrịtara ọnụ;5 - nkewa nke osisi;6 — diaphragm;7 - calorimeter nke ọkụ ọkụ merenụ;8 - calorimeter nke ìhè ọkụ;9 - mita ike beam merenụ;10 - mita ike beam gosipụtara;11 - oghere na-elekwasị anya;12 - mirror;13 - ihe atụ;14 - transducer piezoelectric brọdband;15 - 2D ntụgharị;16 - nhazi microcontroller;17 - ngalaba mmekọrịta;18 - usoro nnweta dijitalụ nke ọtụtụ ọwa nwere ọnụọgụ nlele dị iche iche;19 - kọmputa nkeonwe.
A na-eme ọgwụgwọ Ultrasonic dị ka ndị a. Laser na-arụ ọrụ na ọnọdụ na-agba ọsọ n'efu;Ya mere, oge nke laser usu bụ \ (\ tau _L \ sim 150 ~ \ upmu \ ederede {s} \), nke mejupụtara multiple durations nke mkpokọta \ (1.5~\upmu \ ederede {s } \) ọ bụla. The temporal udi nke laser usu na ya ụdịdị dị iche iche mejupụtara a ala-frequency envelopu na ugboro ugboro nke \ MHz \ , nkezi ~ 0 MHz , na nkezi \ . dị ka e gosiri na Figure 2.- The ugboro envelopu na-enye kpo oku na ụdi agbaze na evaporation nke ihe onwunwe, mgbe elu ugboro akụrụngwa na-enye ultrasonic vibrations n'ihi na fotoacoustic mmetụta.The waveform nke ultrasonic usu eme site laser bụ tumadi kpebisiri ike site na oge udi nke laser usu ike.Ọ bụ site na \ (7 ~\ ederede {kHz} \) na \ (2 ~\ ederede {MHz} \), na etiti ugboro bụ \ (~ 0.7 ~\ ederede {MHz} \) .Acoustic pulses n'ihi na fotoacoustic mmetụta e dekọrọ site na iji brọdband piezoelectric transducers nke polyvinylidene fluoride transducers. A na-edobe ife efe2 na-ekwesịghị igosi na ihe ngosi nke laser na-egosi na ọ bụ ihe ngosi nke ihe nkiri na-eme ka ọ bụrụ ihe ngosi nke laser. ụdị nke laser mode na-agba ọsọ n'efu.
Nkesa oge nke ọkụ ọkụ laser (a) na ọsọ nke ụda n'azụ azụ nke ihe atụ (b), spectra of laser pulse (c) na ultrasonic pulse (d) gbakọrọ ihe karịrị 300 laser pulse (red curve) maka otu ọkụ ọkụ laser (agba anụnụ anụnụ) .
Anyị nwere ike ịmata n'ụzọ doro anya akụkụ dị ala na nke dị elu nke usoro ọgwụgwọ ụda nke kwekọrọ na envelopu dị ala nke laser pulse na mgbanwe dị elu.ya mere, a na-atụ anya isi mmetụta nke eriri brọdband dị elu nke ihe mgbaàmà ụda na microstructure.
Usoro anụ ahụ na SLM dị mgbagwoju anya ma na-eme n'otu oge n'otu oge na nha dị iche iche na nke oge. Ya mere, ụzọ dị iche iche dị iche iche dị mma maka nyocha usoro ihe omimi nke SLM. Ụdị mgbakọ na mwepụ kwesịrị ịdị na mbụ bụrụ multi-physical. The mechanics and thermophysics of a multiphase medium "mgbaze siri ike-mmiri mmiri" na-emekọrịta ihe na ikuku gas inert.
Ọnụ ọkụ ọkụ na jụrụ oyi ruo \(10^6~\text {K}/\text {s}\) /\text{ n'ihi irradiation laser mpaghara nwere njupụta ike ruo \(10^{13}~\ederede {W} cm}^2\).
Usoro mgbaze na-agbaze na-adị n'etiti 1 na \ (10~\text {ms}\), nke na-enye aka n'ike n'ike ngwa ngwa nke mpaghara agbaze n'oge oyi.
Ngwa ngwa kpo oku nke sample elu pụta na e guzobere elu thermoelastic nrụgide na n'elu Layer.Sufficient (ruo 20%) akụkụ nke ntụ ntụ oyi akwa bụ ike evaporated63, nke na-eme ka ihe ọzọ mgbali ibu n'elu na nzaghachi na laser ablation.Consequently, na induced nje budata agbagọ akụkụ nke geometry, karịsịa nso na-akwado na mkpa structural structural agbụ laser na-arụpụta na ultrasonic structural ihe na-emepụta ihe na-emepụta ihe na-emepụta ihe na-emepụta ihe na-emepụta laser. agate site na elu ruo na mkpụrụ. Iji nweta data ọnụọgụ ziri ezi na nrụgide mpaghara na nkesa nkesa, a na-eme simulation mesoscopic nke nsogbu nrụrụ na-agbanwe agbanwe na-ejikọta na ikpo ọkụ na oke nnyefe.
Nhazi nke na-achịkwa ihe nlereanya (1) na-enweghị atụ na-enweghị nsogbu na-adabere na ọnọdụ ikuku (2) A na-akọwapụta flux na-ebugharị nke ọma na ngụkọta nke nrụgide nke na-efe efe nke na-eme ihe na-egbochi ihe dị iche iche. \ (200 ~ \ UpMu \ Text {M \) nke dayameta mpaghara dị mma.
Ọgụgụ 3 na-egosi nsonaazụ ọnụọgụ ọnụọgụ nke mpaghara a wụrụ awụ site na iji ụdị mgbakọ na mwepụ macroscopic. The dayameta nke mpaghara fusion bụ \ (200 ~\upmu \ ederede {m} \) (\ (100~\upmu \ ederede {m} \) radius) na \ (40~\upmu \"ederede {m} \) na-egosi omimi nke mpaghara (40 ~ \ upmu \ ederede {m} \) na-egosi omimi nke mpaghara. t {K} \) n'ihi na elu intermittent ihe nke usu modulation. The kpo oku \ (V_h \) na jụrụ \ (V_c \) ọnụego bụ na iji nke \ (10 ​​^ 7 \) na \ (10 ​​^ 6 ~ \ ederede {K} / \ ederede {s} \), karị . Ndị a ụkpụrụ na-na ezi nkwekọrịta na ihe dị iche n'usoro anyị gara aga nke analysis \ (V)" (V) (10 ^ 6 ~). na-eme ka ikpo ọkụ ngwa ngwa nke oyi akwa elu, ebe ikpo ọkụ na-ekpo ọkụ na mkpụrụ adịghị ezu iji wepụ okpomọkụ. Ya mere, na \ (t=26 ~\upmu \ ederede {s} \) okpomọkụ dị elu dị elu dị ka \ (4800 ~ \ ederede {K} \) .Ọpụpụ siri ike nke ihe ahụ nwere ike ime ka ihe nlele ahụ ghara ịdaba na oke nrụgide.
Ọnụ ọgụgụ ịme anwansị pụta nke agbaze mpaghara nke otu laser usu annealing on 316L sample efere. The oge site na mmalite nke usu na omimi nke a wụrụ awụ ọdọ mmiri na-eru kacha uru bụ \ (180 ~\ upmu \ ederede {s} \) .The isotherm \ (T = T_L = 1723 ~ \ ederede n'etiti mmiri mmiri na-agba ọsọ (K} \) s. ka mkpụrụ nrụgide gbakọọ dị ka ọrụ nke okpomọkụ na ngalaba na-esote. Ya mere, na ngalaba n'etiti abụọ isolines (isotherms \ (T = T_L \) na isobars \ (\ sigma = \ sigma _V (T) \)), a na-edobe usoro siri ike na ibu ọrụ siri ike , nke nwere ike ime ka mgbanwe dị na microstructure.
A na-akọwakwuo mmetụta a na Figure 4a, ebe a na-eme ka nrụgide nrụgide dị na mpaghara a wụrụ awụ dị ka ọrụ nke oge na anya site na elu. Nke mbụ, omume nrụgide na-ejikọta ya na mgbanwe nke laser pulse intensity nke akọwara na Figure 2 n'elu. A na-ahụ oke nrụgide \ ederede {s} \) banyere \ (10 ​​~\ ederede {MPa} \) banyere \ (10 ​​~\ ederede {MPa} \) nke ihe dị ka \ (10 ​​~\ ederede {MPa} \) na-ahụ maka ihe dị ka \ (10 ​​~ \ ederede {MPa} \) na mpaghara. ebe nwere otu oscillation e ji mara dị ka ugboro nke \ (500 ~ \ ederede {kHz} \) .Nke a pụtara na ultrasonic mgbali ebili mmiri na-eme na elu wee gbasaa n'ime mkpụrụ.
A na-egosi njirimara ndị a gbakọọ nke mpaghara nrụrụ dị nso na mpaghara agbaze na Fig. 4b. A na-egosi ablation laser na nrụgide thermoelastic na-emepụta ebili mmiri na-agbanwe agbanwe nke na-agbasa n'ime mkpụrụ ahụ. Dị ka a pụrụ ịhụ site na ọnụ ọgụgụ ahụ, e nwere usoro abụọ nke nrụgide nrụgide. N'oge mbụ nke \ (t <40 ~\upmu \ ederede {s}) na-eme ka [8 MP nrụgide na-ebili n'elu, na-eme ka ọ bụrụ ihe na-eme ka ọ dị elu. . Nchegbu a na-eme n'ihi nkwụsị nke laser, ọ dịghịkwa nrụgide thermoelastic na-ahụ maka ihe nchịkwa n'ihi na mpaghara mbụ nke okpomọkụ na-emetụta dị ntakịrị. Mgbe a na-ekpochapụ okpomọkụ n'ime mkpụrụ ahụ, ebe nchịkwa na-emepụta nrụgide thermoelastic dị elu n'elu \ (40 ~ \ ederede {MPa} \).
The enwetara modulated nrụgide etoju nwere mmetụta dị ịrịba ama na ihe siri ike-mmiri interface na nwere ike ịbụ njikwa usoro na-achịkwa ụzọ solidification.The size nke deformation zone bụ 2 ka 3 ugboro ibu karịa nke na-agbaze zone. Dị ka e gosiri na Figure 3, ebe nke agbaze isotherm na nrụgide larịị nhata nke mkpụrụ nrụgide na-tụnyere. Nke a pụtara na pulsed pulsed n'ibu nke laser \ 0 dị n'etiti mpaghara irradiation dị elu \ 0 na-enye ihe dị elu n'ime 8 irradiation nke mpaghara ~00 n'etiti ebe dị elu nke laser ~00 na dayameta nke mpaghara ~ 0 na-enye ihe dị elu n'ichepụta ihe ọkụkụ ~ 0 mpaghara. mu \text {m}\) dabere na oge ozugbo.
Ya mere, mgbagwoju mgbagwoju anya nke pulsed laser annealing na-eduga ná mmetụta ultrasonic. The microstructure nhọrọ ụzọ dị iche iche ma ọ bụrụ na e jiri ya tụnyere SLM na-enweghị ultrasonic loading.Deformed ejighị n'aka na mpaghara na-eduga na oge cycles nke mkpakọ na ịgbatị na oge siri ike. iji chepụta pulse modulation-induced ultrasound-driven SLM prototype. N'okwu a, enwere ike wepu piezoelectric inductor 26 eji ebe ọzọ.
(a) Nrụgide dị ka ọrụ nke oge, gbakọọ na dị iche iche anya site na elu 0, 20 na \ (40~\upmu \ ederede {m} \) tinyere axis nke symmetry.
Emere nnwale na AISI 321H igwe anaghị agba nchara na nha nha \ (20 \ ugboro 20 \ ugboro 5 ~ \ ederede {mm} \) .Mgbe ọ bụla laser usu, efere na-akpali \ (50~\upmu \ ederede {m} \), na laser doo n'úkwù n'elu lekwasịrị anya n'elu bụ banyere \ (100~U\m na-agafere \ p na nkeji ise). iji mee ka a na-emegharị ihe ndị a na-edozi maka nhazi ọka. N'ọnọdụ niile, mpaghara remelted bụ sonicated, dabere na akụkụ oscillatory nke laser radiation. Nke a na-eme ka mbelata ihe karịrị okpukpu 5 na nkezi ọka. Foto 5 na-egosi otú microstructure nke mpaghara laser-gbazere na-agbanwe na ọnụ ọgụgụ nke na-esote remelting cycles (na-agafe).
Subplots (a,d,g,j) na (b,e,h,k) - microstructure nke mpaghara agbaze laser, subplots (c,f,i,l) - mpaghara nkesa nke ọka acha.Shading na-anọchi anya ihe ndị a na-eji agbakọ histogram. Agba kwekọrọ na mpaghara ọka (lee mmanya agba dị n'elu histogram. Subplots (ac) kwekọrọ na igwe anaghị agba nchara, na subplots (df), (gi), (jl) kwekọrọ na 1, 3 na 5 remelts.
Ebe ọ bụ na ike ọkụ laser adịghị agbanwe n'etiti ngafe ndị na-esote, omimi nke mpaghara a wụrụ awụ bụ otu. N'ihi ya, ọwa na-esote kpamkpam "kpuchie" nke gara aga. Otú ọ dị, ihe ndekọ akụkọ ihe mere eme na-egosi na ebe etiti na etiti ọka na-ebelata na ọnụ ọgụgụ na-arịwanye elu nke ngafe. Nke a nwere ike igosi na laser na-eme ihe na mkpụrụ osisi kama ịgbaze.
Enwere ike ime ka nhazi nke ọka site na ngwa ngwa jụrụ oyi nke ọdọ mmiri a wụrụ awụ65. A na-eme nyocha ọzọ nke na-eme ka ihe ndị dị n'elu nke efere igwe anaghị agba nchara (321H na 316L) na-ekpuchi ọkụ ọkụ na-aga n'ihu na radiation laser na-aga n'ihu na ikuku (Fig 6) na oghere (Fig 7) . The nkezi ike laser (300 W na nkwanye ùgwù 100G) na-arụpụta ihe omimi nke laser na nso nso 100 W. na ọnọdụ na-agba ọsọ n'efu. Otú ọ dị, a hụrụ usoro kọlụm nkịtị.
Microstructure nke mpaghara laser agbazere nke laser na-efegharị efegharị na-aga n'ihu (ike 300 W mgbe niile, ọsọ nyocha 200 mm / s, AISI 321H igwe anaghị agba nchara).
(a) Microstructure na (b) eletrọn backscatter diffraction onyonyo nke mpaghara laser gbazere na oghere na laser na-efegharị efegharị na-aga n'ihu (ike 100 W mgbe niile, 200 mm / s nyocha ọsọ, AISI 316L igwe anaghị agba nchara) \ ( \ SIM 2 ~ \ ederede {mbar} \).
Ya mere, a na-egosi n'ụzọ doro anya na mgbagwoju mgbagwoju anya nke laser usu ike nwere mmetụta dị ịrịba ama na-akpata microstructure.We kwere na nke a mmetụta bụ n'ibu na ọdịdị na-eme n'ihi na ọgbọ nke ultrasonic vibrations propagating si irradiated elu nke gbazee miri n'ime sample.N'ihi ya, e nwetara na 13, 26, 34, 66, 67 electrodes na-eji mpụga nke ultrasound na transduce transduces dị elu nke na-eme ka ihe dị iche iche na-enye ihe dị elu nke ultrasound-piezon transduce transducer transducer transducer transducer transducen transducer transducen transducen transducen transducen transduces na transduces dị iche iche na transduces dị iche iche. 6Al-4V alloy 26 na igwe anaghị agba nchara 34 N'ihi nke. The ekwe omume usoro a na-speculated dị ka ndị a. kpụ ọkụ n'ọnụ ultrasound nwere ike ime ka acoustic cavitation, dị ka e gosiri na ultrafast na situ synchrotron X-ray imaging. The ida nke cavitation egosipụta n'aka site na-akpata ujo ebili mmiri na a wụrụ awụ ihe, onye n'ihu mgbali nwere ike iru \ (tex 10MP). ike zuru oke iji kwalite guzobe nke oké egwu-sized siri ike-phase nuclei na nnukwu mmiri mmiri, na-akpaghasị ahụkarị ọka columnar Ọdịdị nke oyi akwa-site-Layer mmako mmepụta.
N'ebe a, anyị na-atụ aro usoro ọzọ maka structural mgbanwe site ufiop sonication. Ozugbo solidification, ihe bụ na a elu okpomọkụ nso na-agbaze ebe na nwere oké ala mkpụrụ stress.Mmiri ultrasonic ebili mmiri nwere ike ime ka plastic eruba ịgbanwe ọka Ọdịdị nke na-ekpo ọkụ, dị nnọọ ike siri ike material. Otú ọ dị, a pụrụ ịdabere na nnwale data na okpomọkụ dabere na okpomọkụ nke ndabere nke mkpụrụ nchegbu na-adịghị dị na \ (T Figure 5) . n'ihu, iji nwalee nke a hypothesis, anyị rụrụ molekụla dynamics (MD) simulations nke a Fe-Cr-Ni mejupụtara yiri AISI 316 L ígwè iji nyochaa mkpụrụ nchegbu omume nso na-agbaze ebe. Iji gbakọọ mkpụrụ nchegbu, anyị na-eji MD shiee nchegbu usoro izu ike zuru ezu na 70, 71, 72, 73. N'ihi na ihe mgbagwoju anya nke Model, anyị na-eji MD 70, 71, 72, 73 . A na-eme ihe ngosi MD site na iji koodu LAMMPS 75,76. A ga-ebipụta nkọwa nke MD simulations n'ebe ọzọ. A na-egosipụta ngụkọ MD nke nsonaazụ nrụgide dị ka ọrụ nke okpomọkụ na Fig. 8 tinyere data nnwale dị na nyocha ndị ọzọ77,78,79,80,81,82.
Mbelata nrụgide maka ọkwa AISI 316 austenitic igwe anaghị agba nchara na ihe nlere anya na ọnọdụ okpomọkụ maka simulations MD. Nlere nnwale sitere na ntụaka: (a) 77, (b) 78, (c) 79, (d) 80, (e) 81. na-ezo aka. A na-akọwapụta simulations MD buru ibu na ọmụmụ a dị ka \ (\ vartriangleleft \) maka otu kristal na-enweghị ntụpọ na-enweghị ntụpọ na \ (\ vartriangleright \) maka mkpụrụ nwere njedebe na-eburu n'uche nkezi nha ọka site na Hall-Petch relation Dimensions \ (d = 50~\upmu \ ederede {m}).
Ọ nwere ike ịhụ na na \ (T> 1500 ~\ ederede {K} \) mkpụrụ nchegbu tụlee n'okpuru \ (40 ~\ ederede {MPa} \) .N'aka nke ọzọ, atụmatụ na-ebu amụma na laser-emepụta ultrasonic amplitude karịrị \ (40 ~ \ ederede {MPa} \) (lee fig. 4b ihe onwunwe), nke zuru ezu na-ekpo ọkụ na-eme ka plastic na-eruba dị nnọọ ike.
Nhazi microstructure nke 12Cr18Ni10Ti (AISI 321H) austenitic igwe anaghị agba nchara n'oge SLM ka e nyochara nnwale site na iji isi iyi laser pulsed siri ike.
Achọpụtara mbelata nha ọka na mpaghara agbaze laser n'ihi mgbaze laser na-aga n'ihu mgbe 1, 3 ma ọ bụ 5 gafere.
Nlegharị anya nke macroscopic na-egosi na nha atụmatụ mpaghara ebe nrụrụ ultrasonic nwere ike imetụta nke ọma n'ihu siri ike ruo \(1 ~ ederede {mm}).
Ihe ngosi MD microscopic na-egosi na ike mkpụrụ nke AISI 316 austenitic igwe anaghị agba nchara na-ebelata nke ukwuu na \(40~\ ederede {MPa} \) n'akụkụ ebe mgbaze.
Nsonaazụ enwetara na-atụ aro usoro maka ịchịkwa microstructure nke ihe site na iji nhazi laser dị mgbagwoju anya ma nwee ike bụrụ ihe ndabere maka ịmepụta mgbanwe ọhụrụ nke usoro SLM pulsed.
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