Daim Ntawv Qhia
1. Taw qhia
Hauv kev tsim khoom ntxiv (AM), ultrashort pulse (USP) lasers pab ua kom muaj ntau yam khoom siv thiab muaj peev xwm los txo qhov ntev thiab qhov nyuaj ntawm cov khoom tsim. Txoj kev tshawb no qhia txog qhov ua tau ntawm kev siv USP lasers los ua lwm txoj hauv kev rau Laser Powder Bed Fusion (LPBF) systems, tshwj xeeb tshaj yog rau kev tsim cov khoom tseem ceeb uas yuav tsum tau muaj siab dua. Siv cov kev hloov kho thiab tus kheej- ua stainless- cov hmoov hlau hmoov, cov kws tshawb fawb tau ua tiav cov txiaj ntsig xav tau thiab ua tiav cov txheej xwm xwm txheej zoo ib yam los ntawm kev ua kom zoo ntawm cov txheej txheem ua haujlwm.
Txoj kev tshawb fawb tau lees paub tias cov txheej txheem tsis ua lub luag haujlwm tseem ceeb thaum siv USP lasers - txawm tias qhov sib txawv me me hauv cov ntsuas no tuaj yeem ua rau tsis tiav. Los ntawm kev txo cov scanning ceev los txhawb cov cua kub tsub zuj zuj, melting tau tiav ntawm tsawg mem tes repetition zaus (500 kHz) thiab tsawg nruab nrab laser powers (0.5-1 W). Txoj hauv kev no muab lub peev xwm los txo qhov loj me, uas yog qhov tseem ceeb rau kev nce qib AM siv USP laser qhov chaw.
2. Cov ntsiab lus ntawm Kev Kawm
Nrog rau kev txhim kho txuas ntxiv ntawm kev tsim khoom ntxiv, femtosecond lasers qhia tau tias muaj peev xwm ua tiav 316L stainless hlau. Daim ntawv no qhia txog thiab tshuaj xyuas txoj kev tshawb fawb txog kev cuam tshuam ntawm cov txheej txheem tsis nyob hauv femtosecond laser ua ntawm 316L stainless hlau. Lub hom phiaj tseem ceeb ntawm kev tshawb fawb yog los soj ntsuam seb lub zog laser, hmoov particle loj npaum li cas, scanning ceev, thiab hatch nrug cuam tshuam rau kev ua tau zoo thiab cov khoom ua tau zoo, txhawm rau txhim kho kev tsim khoom.
Cov kws tshawb nrhiav thawj zaug tau qhia txog cov yam ntxwv thiab kev tsim nyog ntawm 316L stainless hlau, tom qab ntawd piav qhia txog cov ntsiab lus ua haujlwm thiab cov txheej txheem ntawm femtosecond laser ua. Tom qab ntawd, lawv tau tsom mus rau qhov tseem ceeb ntawm qhov tsis zoo - suav nrog lub zog laser, qhov loj me me, scanning ceev, thiab qhov deb ntawm qhov hatch - cuam tshuam cov khoom zoo.
Los ntawm kev sim cov kev tshawb fawb, pab pawg tau txheeb xyuas qhov kev pom zoo ntawm lub zog laser ntau yam los tiv thaiv kev puas tsuaj ntau dhau thiab cov khoom puas. Lawv kuj pom tau tias cov hmoov hmoov zoo ua rau lub pas dej ua kom zoo dua qub thiab ua kom raug ntau dua. Tsis tas li ntawd, kev hloov kho hauv kev ntsuas nrawm thiab qhov deb ntawm qhov ntsuas tau pom tias txo qis qhov tsis xws luag thiab porosity, txhim kho ob qho tib si zoo thiab ua haujlwm zoo.
Thaum kawg, txoj kev tshawb no tau tham txog daim ntawv thov kev cia siab ntawm femtosecond lasers hauv 316L stainless hlau tsim, qhia txog cov teeb meem tam sim no thiab cov lus qhia yav tom ntej.
3. Kev soj ntsuam thiab cov duab
3.1 USP Laser Txoj Cai
Ultrashort pulse (USP) lasers tsim cov mem tes luv luv, feem ntau hauv femtosecond (10⁻¹⁵ s) mus rau picosecond (10⁻¹² s) ntau yam. Cov lasers no vam khom rau cov teebmeem uas tsis yog-linear optical thiab ultrafast optics.
Cov khoom tseem ceeb ntawm USP laser yog lub resonant kab noj hniav, uas muaj ib tug laser nruab nrab (xws li, Nd:YAG los yog Ti: sapphire siv lead ua) thiab ib tug nce qhov chaw (xws li laser diodes los yog flash teeb). Cov txheej txheem amplification tshwm sim los ntawm kev txhawb nqa emission, qhov twg photons pheej rov xav txog ntawm daim iav hauv cov kab noj hniav thiab yog amplified, thaum kawg tsim ib lub teeb tawm muaj zog.
USP lasers ua tiav ultrashort mem tes ntev los ntawm leveraging nonlinear optical teebmeem xws li tus kheej -theem modulation thiab nonlinear refraction. Cov khoom siv kho qhov muag xws li zaus- ob npaug ntawm cov muaju lossis cov fibers pab nthuav dav thiab nthuav cov mem tes spectrum, mus txog lub sijhawm mem tes hauv qhov femtosecond.
Daim duab 1 – Kub Evolution ntawm txawv Laser Powers
Daim duab 1 qhia txog qhov kub thiab txias hloov nrog lub zog laser sib txawv.
Siab zog (liab nkhaus):kub tshaj qhov melting thiab ablation pib.
Tsawg zog (ntsuab nkhaus):kub tsis txaus rau melting.
Optimal zog (xiav nkhaus):enables melting yam tsis muaj ablation.
Daim duab 2 - SEM duab ntawm ntxhib thiab zoo hmoov
Ceit tsim cov pa roj carbon monoxide- atomized hlau hmoov rau AM. Ob hom hmoov tau siv:
Coarse hmoov (20-45 µm)
Hmoov zoo (<20 µm)
Cov hmoov zoo tau txais kev txhim kho yaj tswj thiab txheej txheej uniformity.
Daim duab 3 - Thawj Txheej Txheej Txheej Txheem
Txhawm rau txhim kho cov hmoov adhesion, lub substrate yog thawj laser- kho kom roughness saum npoo. Profilometric tsom xam pom qhov roughness (Sa) ntawm 3.3 µm thiab qhov tob ntawm 51.499 µm. Cov khaubncaws sab nraud povtseg tau siv los siv txoj kev hniav, ua tiav cov tuab tuab:
Coarse hmoov: 100-200 µm txheej
Cov hmoov zoo: 50 µm txheej
Daim duab 4 - Lub zog cuam tshuam rau kev ua cov hmoov coarse
Kev siv USP lasers hauv AM nthuav tawm qhov kev sib tw: yaj cov hmoov tsis ua rau ablation. Lub hwj chim ntau dhau ua rau muaj qhov ejection los yog substrate puas. Txo lub zog laser hauv qab lub ablation pib ua rau muaj kev vam meej.
Ntawm lub zog qis dua 0.5 W, cov hmoov zoo tseem tsis cuam tshuam, thaum siab tshaj qhov pib no, cov khoom tawg thiab coalesce rau hauv qhov loj dua.
Daim duab 5 - Lub zog hloov pauv ntawm cov hmoov zoo
Ua kom muaj zog ntawm 0.59 W txog 0.765 W txhim kho melting, ua kom smoother thiab ntau yam xim. Qhov saum npoo roughness (Sa) txo los ntawm 3.45 µm rau 2.58 µm.
Daim duab 6 – Cov nyhuv ntawm Scanning ceev
Ntawm 0.674 W thiab 10 µm hatch nrug:
Txo cov scanning ceev ntawm 5 mm / s mus rau 2.5 mm / s nce tshav kub thiab particle coalescence, enlarging pawg thiab raising Sa los ntawm 5.43 µm rau 6.75 µm.
Ntawm 0.765 W, kev soj ntsuam qeeb ua rau cov txiaj ntsig zoo dua (Sa ≈ 3.9–4.1 µm).
Daim duab 7 - Kev sib xyaw ua ke ntawm lub zog thiab nrawm
Nyob rau theem siab zog (0.85–0.935 W) thiab scanning ceev mus rau 2.5 mm / s, Sa ntxiv txo mus rau 3.5–3.8 µm. Hauv qab 1.5 mm / s, overheating ua rau cov hmoov tawg thiab hlawv.
Daim duab 8 – Hatch Distance Reduction
Txo qhov kev ncua deb ntawm 7 µm mus rau 5 µm txhim kho qhov chaw zoo heev - Sa poob ntawm 6.75 µm mus rau 4.1 µm. Ntau dhau qhov kev ncua deb tau ua rau tsis sib xws ntawm melting thiab defect tsim.
Daim duab 9 – Hatch Distance Influence
Nyob rau hauv qhov zoo tshaj plaws lub hwj chim thiab ceev qhov rais, txo hatch nrug tsis tu ncua txhim kho nto uniformity, ua tiav Sa tsawg li 2-3 µm. Kev hloov kho hauv kev nrawm yog tsim nyog los sib npaug ntawm cov cua sov sib xyaw.
Daim duab 10 – Cov txheej txheem zoo tshaj plaws
Qhov kev ua haujlwm zoo tshaj plaws tau ua tiav qhov zoo sib xws ntawm cov nplaum nplaum nrog Sa ntawm 2.37 µm siv:
Laser zog:0.775 W
Scanning ceev:2.5 hli / s
Hatch nrug:7.5 µm
4. Cov lus xaus
Txhawm rau ntsuas qhov muaj peev xwm ntawm USP lasers hauv kev tsim khoom ntxiv, femtosecond lasers tau muab tso rau hauv cov txheej txheem LPBF siv ob hom stainless- hlau hmoov. Txoj kev tshawb no xaus li ntawdlaser zogyog qhov tseem ceeb tshaj plaws - lub zog ntau dhau ua rau ablation, thaum me me heev tiv thaiv melting.
Thaum lub qhov rais fais fab pom zoo tau tsim (0.775–0.935 W), zoo -tu lub scanning ceev thiab hatch nrug ntxiv txhim kho nto smoothness. Cov txiaj ntsig zoo tshaj plaws tau ua tiav ntawm:
Lub zog: 0.775–0.935 W
Scanning ceev:2.5 hli / s
Hatch nrug: 5–7.5 µm
Raws li cov kev ua tau zoo no, cov txheej txheem melting thiab qhov me me ntawm qhov roughness tau ua tiav, lees paub qhov ua tau ntawm USP lasers rau siab -precision additive manufacturing ntawm micro- nplai Cheebtsam.
