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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 na 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 na-ajụ oyi na-agbaze usoro, siri ike ọdọ mmiri na-agbaze na granuter dị elu. mgbagwoju anya nke usoro ikpo ọkụ na ihe na-agbaze na mgbaze11, nke na-eduga n'ọba ọka epitaxial na porosity dị ịrịba ama12,13. 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-eche banyere mmetụta nke ọgwụgwọ vibration na usoro siri ike na usoro nkedo a na-emekarị14,15. Otú ọ dị, itinye ebe dịpụrụ adịpụ na nnukwu agbaze adịghị emepụta microstructure ihe a chọrọ.If the volume of the liquid phase is small, the status changes dramatically.In this case, the external field significantly emetụta ndị siri ike usoro.Electromagnetic mmetụta e weere n'oge ufiop mmetụta e weere n'oge ufiop mmetụta. ubi16,17,18,19,20,21,22,23,24,25,26,27, arc stirring28 na oscillation29, pulsed plasma arcs30,31 na ụzọ ndị ọzọ32 .Tinye na mkpụrụ iji mpụga elu-ike ultrasound isi iyi (na 20 kHz bụ ọka refined emepụtara na ultrasound). mpaghara subcooling n'ihi mbelata okpomọkụ gradient na ultrasound nkwalite n'ịwa ọhụrụ crystallites site cavitation.
Na 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 merenụ na ìhè-absorbing ọkara pụta na ọgbọ nke ultrasonic ebili mmiri, nke na-agbanwe microstructure nke material.The ike modulation nke dị mfe 3 laser ebipụta nwere ike na-ebipụta na-arụ ọrụ laser. A na-eme ya na efere igwe anaghị agba nchara nke elu ya na-ekpuchi ọkụ 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 nke ọ bụla oyi akwa, n'oge oyi akwa-site-layer-ewuli elu, mmetụta na dum olu ma ọ bụ na ahọrọ akụkụ nke olu na-enweta.
Ebe na ultrasonic mpi nke dabeere na ultrasonic ọgwụgwọ, a na-ekesa ike ultrasonic nke ụda ụda na-eguzo ọtọ na mpaghara ahụ dum, ebe laser-induced ultrasonic intensity na-etinye uche nke ukwuu n'akụkụ ebe a na-etinye ọkụ ọkụ laser. Iji sonotrode na SLM ntụ ntụ bed fusion igwe na-agbagwoju anya n'ihi na elu elu nke ntụ ntụ ntụ ekpughere na laser radieshon kwesịrị ịnọgide na-eguzosi ike n'ihe.Na mgbakwunye, ọ dịghị ihe na-arụ ọrụ n'elu. acoustic nchegbu dị nso na efu na urughuru ngwa ngwa nwere a kacha njupụta n'elu dum elu elu nke part.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} na-emekarị bụ ihe na-erughị 0.3 n'arọ (\ SIM 0.3}). 0.3 ~ \ ederede {mm} \) .Ya mere, mmetụta nke ultrasound na cavitation nwere ike ịbụ obere.
Okwesiri iburu n'uche na iji radieshon-modulated laser siri ike na ntinye igwe laser kpọmkwem bụ mpaghara na-arụ ọrụ nke 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, na-arụpụta na excitation nke acoustic ebili mmiri na ya na ihe ma ọ bụ na-erughị efficiency.Initially, isi na-elekwasị anya na laser excitation nke ebili mmiri na mmiri mmiri na dị iche iche thermal excitation usoro nke ụda (mgbasawanye thermal, evaporation, 4 nkwekọrịta mgbanwe, oge mgbanwe 4, wdg). 49.Ọtụtụ monographs50, 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 nyocha 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. na a doo splitter 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 na-egosipụta site na ìhè splitter na-eri nri ka a photodiode data abụọ a simulition. (photodiodes na ogologo nzaghachi oge gafere \ (1 ~\ ederede {ms}\)) na-eji iji chọpụta ihe merenụ na na-egosipụta site lekwasịrị anya, na abụọ ike mita (photodiodes na obere nzaghachi ugboro \ (<10~\text {ns}\)) iji chọpụta ihe merenụ na-egosipụta ike ngwa anya.Calorimeters na ike mita e calibrated na-enye ụkpụrụ na-eji Gensole detector na-eji Gensole detector na-enye ụkpụrụ na a zuru oke. XLP12-3S-H2-D0 na enyo dielectric etinyere na ebe nlele. Lekwasị anya n'ọkụ ahụ n'elu ebumnuche site na iji oghere (Antireflection mkpuchi na \ (1.06 \ upmu \ ederede {m} \), ogologo focal \ (160 ~\ ederede {mm} \)) na úkwù n'úkwù n'elu ebe a na-eche ihu 160.
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 modulation nke ihe dị elu - (1.5~\upmu \ ederede {s} \) ọ bụla. {MHz} \), 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 ruru ka photoacoustic 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 ugboro etiti bụ \ (~ 0.7 ~ \ ederede {MHz} \) .Acoustic pulses n'ihi mmetụta fotoacoustic e dekọrọ site na iji brọdband piezoelectric transducers nke polyvinylidene fluoride transducers mere nke polyvinylidene fluoride ihe nkiri. Edekọrọ ihe nkiri na-egosi na ebili mmiri na-egosi na ya Figure2. pulses laser bụ 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 elu Layer.Sufficient (ruo 20%) akụkụ nke ntụ ntụ oyi akwa na-ike evaporated63, nke na-eme ka ihe mgbakwunye nrụgide ibu n'elu na nzaghachi na laser ablation.Consequently, na-akpata nje budata agbagọ na akụkụ nke geometry, karịsịa nso na-akwado na mkpa structural akọrọ ọnụ ọgụgụ laser na-arụpụta ihe na ultrasonic structural ọnụ ọgụgụ nke laser. ebili mmiri nke na-agbasa site n'elu ruo na mkpụrụ. Iji nweta data ọnụọgụ ziri ezi na nrụgide mpaghara na nkesa nkesa, a na-eme ihe ngosi mesoscopic nke nsogbu nrụrụ na-agbanwe agbanwe na-ekpo ọkụ na oke nnyefe.
Ndị na-achị equations nke nlereanya na-agụnye (1) okpomọkụ na-adịghị agbanwe agbanwe equations ebe thermal conductivity na-adabere na-adọ ala (ntụ ntụ, gbazee, polycrystalline) na okpomọkụ, (2) fluctuations na elastic deformation mgbe continuum ablation na thermoelastic mgbasa equation.The ókè uru nsogbu kpebisiri ike site ibuo ọnọdụ. The modulated na-ekpo ọkụ na-ekpo ọkụ sample na-akọwapụta n'elu ikpo ọkụ na-ekpo ọkụ laser. Flux. A na-akọwapụta ụda uka na-adabere na ngụkọ nke nrụgide vapor juputara nke ihe na-ekpo ọkụ. A na-eji mmekọrịta elastoplastic nrụgide nrụgide na-eme ihe na-eme ka nrụgide thermoelastic kwekọọ na ọdịiche okpomọkụ. Maka ikike aha aha \ (300 ~ \ ederede {W} \), ugboro \ (10 ​​^ 5 ~ \ ederede {Hz} na-arụ ọrụ nke ọma), ugboro ugboro \ (10 ​​^ 5 ~ \ ederede {Hz}), intermittent. {m}\ ) nke dayameta beam dị irè.
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 nsonaazụ mpaghara na-egosi omimi oge. \ (100 ~\ ederede {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} \), otu n'otu n'otu . Ndị a dị mma n'usoro na aga na nkwekọrịta n'etiti anyị 4 ụkpụrụ dị iche iche na-na analysis. \ (V_h \) na \ (V_c \) na-ebute ngwa ngwa ekpo oke ọkụ nke oyi akwa elu, ebe ikpo ọkụ na-ekpo ọkụ na mkpụrụ adịghị ezu iji wepụ okpomọkụ ahụ. Ya mere, na \ (t = 26 ~ \ upmu \ ederede {s} \) elu okpomọkụ elu dị elu dị ka \ (4800 ~\ ederede ihe {K} \) ike na-eme ka ihe nlele anya na-eme ka ihe nlele ahụ pụọ.
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 mmiri mmiri na nke siri ike n'etiti s) na-anọchi anya {K} frasi. (ahịrị edo edo) kwekọrọ na nrụgide mkpụrụ nke gbakọrọ dị ka ọrụ nke okpomọkụ na ngalaba na-esote. Ya mere, na ngalaba dị n'etiti isolines abụọ (isotherms \ (T = T_L \) na isobars \ (\ sigma = \ sigma _V (T) \)), a na-edobe usoro siri ike na ibu ọrụ siri ike, nke nwere ike iduga mgbanwe na microstructure.
A na-akọwakwa 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 ọkụ ọkụ laser nke a kọwara na ọnụ ọgụgụ 2 n'elu. A na-ahụta nrụgide kachasị \ ederede {s} \) banyere \ (10 ​​~\ ederede {MPa} \) banyere \ (10 ​​~\ ederede {MPa} \) banyere \ (10 ​​~\ ederede {MPa} \) na banyere \ (10 ​​~\ ederede {MPa}\). nrụgide mpaghara na ebe nchịkwa nwere otu njirimara oscillation dị ka ugboro nke \ (500 ~\ ederede {kHz} \) .Nke a pụtara na ultrasonic nrụgide ebili mmiri na-eme ka ọ dị n'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 {8 na-eme ka nrụgide na-ebilite . yiri nrụgide elu. Nsogbu 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-ekpo ọkụ na-ekpo ọkụ 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 mpaghara 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-atụnyere.Nke a pụtara na pulsed na-arụ ọrụ laser na dayameta nke mpaghara 3 na-enye n'etiti igwe ọkụ ọkụ eletrik 3 dị elu na mpaghara 3 na-arụ ọrụ nke ọma. \(800~\upmu \ederede {m}\) 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. Nkwubi okwu na-enye ohere ịmepụta ihe ngbanwe nke pulse na-akpata ultrasound-driven SLM prototype. N'okwu a, enwere ike iwepụ 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 n'úkwù laser n'úkwù n'elu lekwasịrị anya bụ ihe dị ka \ (100~\U \ m na-agafe 5 nkeji). rụrụ n'otu egwu ahụ ka ọ na-eme ka a na-emegharị ihe ndị a na-emepụta 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 mpaghara. Ọnụ ọgụgụ 5 na-egosi otú microstructure nke mpaghara laser gbazere na-agbanwe na ọnụ ọgụgụ nke ndị na-esote remelting (na-emegharị okirikiri).
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 mkpocha ọka ngwa ngwa ngwa ngwa nke ọdọ mmiri a wụrụ awụ65. A na-eme nyocha ọzọ nke na-eme ka elu nke efere igwe anaghị agba nchara (321H na 316L) na-ekpuchi ọkụ ọkụ na-aga n'ihu na radiation radiation na-aga n'ihu na ikuku (Fig 6) na oghere (Fig 7) . The nkezi ike laser (300 W na nkwanye ùgwù 100 W, na nso nso nke ọdọ mmiri 100 W, nke na-eme ka ọ bụrụ ihe omimi nke omimi) Nd:YAG laser na ọnọdụ na-agba ọsọ n'efu. Otú ọ dị, a na-ahụ ihe nhazi kọlụm.
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 ultrasound na transduce transduce ultrasound. dị iche iche ihe gụnyere Ti-6Al-4V alloy 26 na igwe anaghị agba nchara 34 N'ihi nke. The ekwe omume usoro na-speculated dị ka ndị a. Mkpịsị aka 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 na-emepụta ujo ebili mmiri na moltons ihe, onye n'ihu \ 100 na-erute ihe, ihe dị n'ihu. {MPa}\) 69. Dị otú ahụ ujo ebili mmiri nwere ike ike zuru ezu iji kwalite guzobe nke oké egwu-sized siri ike-phase nuclei na nnukwu mmiri mmiri, na-akpaghasị ahụkarị columnar ọka Ọdịdị nke oyi akwa-site-Layer mmakwụnye.
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.Intense 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 ndabere nke mkpụrụ nchegbu na-adịghị dị na \ (T Figure \ 0) 8) .Ya mere, iji nwalee echiche a, anyị na-eme ihe ngosi molecular dynamics (MD) nke ihe mejupụtara Fe-Cr-Ni yiri AISI 316 L steel iji nyochaa omume nrụgide mkpụrụ n'akụkụ ebe mgbaze. Iji gbakọọ nrụgide mkpụrụ, anyị na-eji MD shear stress relaxation technique zuru ezu na 70, 71, 72, 72, interatomic e ji mee ihe na-emekọrịta ihe. A na-eme ihe nlereanya (EAM) site na 74.MD simulations site na iji koodu LAMMPS 75,76. A ga-ebipụta nkọwa nke ihe ngosi MD n'ebe ndị ọzọ. A na-egosipụta nsonaazụ ngụkọ MD nke nrụgide mkpụrụ 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. Nleba anya site na ntụaka: (a) 77, (b) 78, (c) 79, (d) 80, (e) 81. na-ezo aka. ihe mgbakwunye mmepụta ihe.The results nke nnukwu ọnụ ọgụgụ MD simulations na ọmụmụ a na-denated dị ka \ (\ vartriangleleft \) maka ntụpọ-free enweghi ngwụcha otu crystal na \ (\ vartriangleright \) n'ihi na njedebe grains na-ewere n'ime akaụntụ nkezi ọka size site na Ụlọ Nzukọ-Petch Relation Dimensions \ (d = 50~\upmu \) ederede.
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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