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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. okirikiri na agbaze na agbaze ihe 11, nke na-eduga na epitaxial ọka ibu na ịrịba porosity.12,13 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, dị ka 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 microstructure ihe achọrọ. ,26,27, arc stirring28 na oscillation29, electromagnetic mmetụta n'oge pulsed plasma arcs30,31 na ndị ọzọ method32 e weere .Attach na mkpụrụ iji mpụga elu-ike ultrasound isi iyi (na 20 kHz) .The ultrasound-induced ọka nnụcha na-ekwu na-amụba constitutive subcoolite n'ihi na kristal okpomọkụ n'ime ọhụrụ subcoolite na-ebelata okpomọkụ site n'ịkwalite kristal subcoolite n'ịwa.
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 ihe ndabere maka fọrọ nke nta niile ihe onwunwe nhazi laser usoro 39, 40, dị ka ịcha 41, ịgbado ọkụ, hardening, mkpọpu ala 42, elu ihicha, elu alloying, elu polishing 43, etc.materials nhazi technology na summarized mbido pụta na ọtụtụ reviews na monographs 44, 64 .5 .
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 nwa oge nke ike iku ume laser (a) na ụda ọsọ (b) n'azụ azụ nke ihe nlele ahụ, ihe nlere anya (nke na-acha anụnụ anụnụ) nke otu pulse laser (c) na ultrasound pulse (d) ruru ihe karịrị 300 laser pulses (mkpụrụ uhie uhie) .
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 image nke laser agbaze mpaghara nke agụụ na-aga n'ihu na-efegharị efegharị laser (ike mgbe niile 100 W, scanning ọsọ 200 mm/s, 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. The ihe dị nnọọ mgbe solidification bụ na a elu okpomọkụ nso nso na-agbaze ebe na nwere oké ala mkpụrụ stress.Mkpa ultrasonic ebili mmiri nwere ike ime ka plastic eruba ịgbanwe ọka Ọdịdị nke na-ekpo ọkụ ihe dị nnọọ solidified. Otú ọ dị, a pụrụ ịdabere na nnwale data na okpomọkụ dabere nke mkpụrụ nchegbu dị na \ (T \ lessem \ 0} 115 {foto). hypothesis, anyị na-eme ihe ngosi molecular dynamics (MD) nke ihe mejupụtara Fe-Cr-Ni yiri AISI 316 L ígwè iji nyochaa àgwà nrụgide mkpụrụ n'akụkụ ebe mgbaze. Iji gbakọọ nrụgide mkpụrụ, anyị na-eji MD shear stress relaxation technique nkọwa zuru ezu na 70, 71, 72, 73. Maka interatomic interaction embed , anyị na-eji EMDto 4 eme ihe na-emekọ ihe. iji LAMMPS codes 75,76.A ga-ebipụta nkọwa nke simulation MD n'ebe ọzọ. The MD ngụkọta oge pụta nke mkpụrụ nrụgide dị ka a ọrụ nke okpomọkụ na-egosi na fig. 8 ọnụ na dị nnwale data na ndị ọzọ evaluations77,78,79,80,81,82.
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. -scale MD simulation results na ọmụmụ a na-akọwara dị ka \ (\ vartriangleleft \) maka otu kristal enweghị ntụpọ na-enweghị ntụpọ na \ (\ vartriangleright \) maka oke ọka 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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