01
Ntawv Taw Qhia
Directed Energy Deposition (DED)-tseem hu ua laser cladding- yog cov txheej txheem tsim khoom siv ntxiv uas siv lub siab -lub zog laser ua ke nrog coaxial hmoov pub system los tsim cov khoom hlau los ntawm txheej. Tsis zoo li cov txheej txheem casting thiab machining ib txwm muaj, cov khoom siv ntawm cov txheej txheem tso rau hauv DED tuaj yeem sib txawv vim qhov kev hloov pauv tsis tu ncua ntawm cov txheej txheem ua haujlwm -xws li txheej qhov siab, scanning ceev, thiab lub zog laser - thaum lub sijhawm tsim khoom. Txawm hais tias muaj ntau qhov kev nce qib tau ua tiav hauv DED thev naus laus zis, kev tshawb fawb rau hauv * hauv-situ* kev ntsuam xyuas ntawm cov khoom siv kho tshuab- xws li Young's modulus thiab Poisson tus piv-thaum ua haujlwm tseem tsis tshua muaj; qhov no ua rau *hauv-situ* saib xyuas thiab kev lees paub zoo tshwj xeeb yog qhov tseem ceeb.
02
**Study Overview**
Txoj kev tshawb no txhim kho qhov tsis yog -kev sib cuag, hauv -situ txheej txheem rau kev soj ntsuam cov khoom siv hluav taws xob ntawm cov ntaub ntawv ua tiav los ntawm Txoj Kev Directed Energy Deposition (DED). Cov txheej txheem tshiab no ua ke nrog femtosecond laser ultrasonics nrog laser polishing kom ua tiav tsis yog-kev sib cuag thiab tsis-kev ntsuas kev puas tsuaj ntawm Young's modulus thiab Poisson tus piv. Los ntawm kev siv femtosecond laser-tsim ultrasonic nthwv dej hauv GHz mus rau THz zaus ntau, lub kaw lus ua tiav sub-micron spatial daws teeb meem, yog li ua kom yooj yim rau siab -zoo, txheej-los ntawm- txheej txheej ntsuas. Txhawm rau hais txog qhov kev sib tw ntawm kev kuaj xyuas cov teeb liab ultrasonic thaum lub ntsej muag roughness nyob rau hauv cov txheej txheem deposited, cov kev tshawb fawb pab neeg ua hauj lwm nyob rau hauv -situ laser polishing{13}} ntau dua li cov tsoos mechanical polishing - uas ua rau muaj txiaj ntsig zoo rau kev tshawb pom ntawm ultrasonic tsis. Cov kev ntsuam xyuas tau ua raws li ntau yam kev ua haujlwm DED pom tau tias cov khoom siv kho tshuab ntsuas los ntawm cov txheej txheem no pom tau tias muaj kev sib raug zoo nrog cov txiaj ntsig tau los ntawm kev ywj pheej tensile kev sim ua tom qab cov txheej txheem fabrication tiav.
03
**Illustrated Analysis**
Daim duab 1 nthuav qhia schematic txheej txheem cej luam ntawm tag nrho cov workflow rau hauv -situ mechanical property assessment technical in the DED process. Nws qhia meej txog cov txheej txheem tseem ceeb- pib los ntawm substrate- uas ua tiav qhov kev kwv yees ntawm cov txheej txheem tso rau ntawm Young's modulus thiab Poisson tus piv los ntawm plaub kauj ruam sib txawv: Kauj Ruam 1 siv DED laser los ua cov txheej txheem DED, fusing thiab depositing ntawm cov hmoov txheej nrog cov thickness ntawm ED. 100 μm; Kauj ruam 2 re-lub hom phiaj polishing laser (uas tej zaum yuav yog tib yam li lub DED laser) ua laser polishing; los ntawm remelting, tus txheej txheem no tsim ib tug du remelted txheej nyob rau saum npoo ntawm cov khoom deposited, txo cov zauv txhais tau tias roughness rau kwv yees li 0.3 μm; Kauj Ruam 3 ntiav ib femtosecond laser kom excite thiab ntsuas ultrasonic tsis nyob rau hauv lub GHz-THz zaus ntau nyob rau hauv lub solidified cheeb tsam tom qab polishing; Kauj Ruam 4 kwv yees tus Young's modulus thiab Poisson tus piv raws li ntsuas ntsuas ultrasonic, nrog rau kev ntxhov siab{12}}txoj kev sib raug zoo. Daim duab kos kuj tseem muaj cov lus piav qhia sib xws uas qhia txog cov khoom siv laser tseem ceeb thiab cov kev hloov pauv ntawm lub ntsej muag cuam tshuam nrog txhua kauj ruam, yog li muab qhov pom kev pom ntawm cov txheej txheem tag nrho tsis yog -kev sib cuag thiab tsis yog- tus yam ntxwv puas tsuaj thoob plaws nws tag nrho "kev tso nyiaj-polishing-nrhiav-kev kwv yees" ua haujlwm.
Daim duab 2 nthuav qhia qhov kev sib piv kev tshuaj ntsuam xyuas qhov cuam tshuam ntawm laser polishing ntawm qhov roughness ntawm DED hlau txheej. Muaj peb lub subfigures-(a), (b), thiab (c)- qhov kev tshuaj ntsuam yog ua nyob rau hauv peb qhov ntev: qhov tsis muaj ntau, macroscopic morphology, thiab microscopic topography, nrog rau lub hauv paus tsom mus rau qhov zoo tshaj plaws ntawm polishing parameters pom rau cov qauv kuv-11. Subfigure (a) qhia cov lus ntau ntawm qhov roughness qhov tseem ceeb sib xws rau 16 qhov sib txawv polishing tsis sib xyaw ua ke, hla polishing zog ntawm 200-350 W thiab polishing ceev ntawm 13-21 mm / s. Cov lus no piav qhia qhov tseeb Ra qhov tseem ceeb ntsuas tom qab polishing 16 ib zaug - txheej lem ntawm cov qauv kuv, qhia meej txog qhov sib xyaw ua ke ntawm 300 W + 18 mm / s raws li qhov kev pom zoo teeb tsa (I-11, Ra=0.31 μm); Tsis tas li ntawd, nws qhia txog cov teeb meem cuam tshuam nrog rau lwm qhov tsis sib xws -tshwj xeeb, ntau dua roughness qhov tseem ceeb uas tshwm sim los ntawm qis- zog, siab{21}} nrawm ua ke, thiab nyiam rau siab - zog, qis- sib xyaw ua ke kom ua rau muaj qhov sib txawv ntawm cov hmoov evaporation. Subfigure (b) nthuav qhia qhov ze-up macroscopic sib piv ntawm cov qauv I-11 ua ntej thiab tom qab polishing nrog cov kev pom tsis zoo, pom qhov pom kev txhim kho tseem ceeb hauv qhov chaw tiaj tus thiab sib xws tom qab txheej txheem polishing. Subfigure (c) muab kev sib piv ntawm cov duab kho qhov muag tsom iav (ntawm qhov ntsuas qhov sib npaug ntawm 40 μm) qhia cov qauv I-11 tom qab pom kev polishing (sab laug) piv rau nws lub xeev tsis zoo (txoj cai); Lub ntsej muag tsis zoo yog tus cwj pwm los ntawm kev nplua nuj ntawm cov hmoov tsis sib xws, qhov tsis sib xws tseem ceeb, thiab cov tsos tsaus dua uas tshwm sim los ntawm lub teeb tawg, thaum lub ntsej muag polished zoo li tsis muaj hmoov tsis muaj hmoov, zoo li tiaj tus thiab du, thiab nthuav tawm cov teeb pom kev zoo. Thaum kawg, qhov kev pom zoo no tau teeb tsa txo qhov roughness ntawm tus nqi pib ntawm 4.2 μm mus rau 0.31 μm-kev txhim kho tus nqi ntawm 93%. Los ntawm qhov kev sib piv tripartite encompassing ntau cov ntaub ntawv, macroscopic morphology, thiab microscopic topography, daim duab zoo validates lub efficiency ntawm laser polishing nyob rau hauv txo cov nto roughness ntawm DED hlau khaubncaws sab nraud povtseg thaum ib txhij tsim cov txheej txheem tsis zoo rau laser polishing.
