Tsis ntev los no, lub koom haum ntawm Mechanics ntawm Tuam Tshoj Academy of Sciences tau koom tes nrog cov kws tshawb fawb hauv tsev thiab txawv teb chaws los ua kom muaj kev vam meej tshiab hauv kev tiv thaiv kev laus ntawm cov ntaub ntawv iav, thiab thawj zaug tau sim ua kom pom cov qauv hluas nkauj ntawm cov iav zoo nkauj hauv lub sijhawm ntsuas ultra-ceev ceev. Cov txiaj ntsig muaj feem cuam tshuam yog hu ua Ultrafast extreme rejuvenation of metallic tsom iav los ntawm kev poob siab compression, luam tawm hauv Science Advances (Science Advances 5: eaaw6249 (2019)).
Cov khoom siv iav metastable muaj qhov nyiam ntawm kev laus raws li lub sijhawm thermodynamic equilibrium lub xeev, thiab nyob rau tib lub sij hawm, nws yog nrog los ntawm deterioration ntawm cov khoom siv. Txawm li cas los xij, los ntawm kev tawm tswv yim ntawm lub zog sab nraud, cov khoom siv iav aging tuaj yeem ua rau cov qauv (rejuvenation). Cov txheej txheem tiv thaiv kev laus no ntawm ib sab ua rau kev nkag siab yooj yim ntawm kev coj tus cwj pwm tsis zoo ntawm iav, ntawm qhov tod tes nws kuj yog qhov tsim nyog rau kev siv engineering ntawm cov ntaub ntawv iav. Nyob rau hauv xyoo tas los no, rau cov khoom siv iav hlau nrog dav daim ntawv thov kev cia siab, cov txheej txheem ntawm cov txheej txheem rejuvenation raws li tsis-affine deformation tau raug npaj kom tswj tau zoo ntawm cov khoom siv thiab lub cev ntawm cov khoom. Txawm li cas los xij, tag nrho cov kev rov ua dua qub dhau los ua haujlwm ntawm cov kev ntxhov siab qis dua thiab xav tau lub sijhawm ntev txaus, thiab yog li muaj kev txwv loj.
Cov kws tshawb fawb raws li ob lub hom phiaj phaj cuam tshuam thev naus laus zis ntawm cov cuab yeej siv roj teeb, pom tau tias cov iav zirconium-raws li nws yog xim hlau sai sai rejuvenated mus rau theem siab nyob rau hauv li 365 nanoseconds (ib lab ntawm lub sij hawm nws yuav siv sij hawm rau ib tug neeg kom ntsais muag. qhov muag). Enthalpy yog qhov tsis zoo heev. Qhov kev sib tw ntawm cov thev naus laus zis no yog siv ob peb GPa-theem ib leeg-pulse loading thiab tsis siv neeg thauj khoom mus rau cov iav hlau, kom tsis txhob muaj qhov tsis ua haujlwm ntawm cov ntaub ntawv xws li shear bands thiab spallation; Nyob rau tib lub sijhawm, los ntawm kev tswj xyuas qhov cuam tshuam nrawm ntawm daim ntawv tshaj tawm, cov hlau Lub nrawm nrawm ntawm iav "freezes" ntawm ntau qib.
Cov kws tshawb fawb tau ua tiav txoj kev tshawb fawb ntawm cov txheej txheem ultra-ceev rejuvenation ntawm cov iav hlau los ntawm qhov kev xav ntawm thermodynamics, ntau cov qauv thiab phonon dynamics "Bose ncov", qhia tias rejuvenation ntawm iav qauv los ntawm nano-scale pawg. Dawb ntim induced los ntawm "shear hloov" hom. Raws li qhov kev siv lub cev no, tus naj npawb tsis muaj Deborah tau txhais, uas piav qhia txog qhov muaj peev xwm ntawm lub sijhawm ntsuas ntawm ultra-ceev rejuvenation ntawm iav hlau. Qhov kev ua haujlwm no tau nce lub sijhawm teev rau kev rov ua dua tshiab ntawm cov qauv iav hlau los ntawm tsawg kawg 10 qhov kev txiav txim ntawm qhov loj, nthuav dav daim ntawv thov teb ntawm cov khoom siv no, thiab ua rau tib neeg nkag siab tob txog cov iav ultrafast dynamics.
Post lub sij hawm: Dec-06-2021