Laser ua ntawm hlau ua npuas ncauj

Metallic foams yog categorized rau hauvqhib-cell thiab kaw-cell foams. Kaw-cell foams muaj cov membranes uas cais cov nyob sib ze los yog cov voids, whereas open-cell foams muaj ib tug network ntawm randomly faib voids uas yog interconnected raws li qhia nyob rau hauv daim duab (a) thiab (b), feem. Lub categorization yog ib qho tseem ceeb heev vim nws paub qhov txawv ntawm cov hlau nplaum raws li lawv daim ntawv thov. Kaw-cell hlau foams muaj siab tawv thiab yog tsuas yog siv nyob rau hauv cov qauv siv. Ntawm qhov tod tes, qhib-cell foams feem ntau yog siv rau hauv kev ua haujlwm xws li cov khoom siv hluav taws xob sib txawv vim lawv qhov chaw loj thiab cov qauv sib txuas nrog cov ntxeem tau.

Yog li ntawd, cov txheej txheem ua haujlwm feem ntau yog lub luag haujlwm raucustomizing hlau foamsrau lawv daim ntawv thov los ntawm kev txhais lawv cov qauv anatomical lossis pore faib. Cov txheej txheem ua tau dav categorized rau hauv cov txheej txheem ua kua thiab khoom. Kev ua kua dej yog qhov nrov tshaj plaws hauv kev lag luam ntau lawm vim tias muaj cov foaming siab thiab cov txiaj ntsig siab. Cov txheej txheem tsim cov pores nyob rau hauv cov kua los yog semi-solid hlau los ntawm ob qho tib si ntawm ob txoj kev tseem ceeb, ncaj qha thiab indirect foaming. Direct foaming tuaj yeem ua tiav los ntawm kev qhia cov pa roj (cua, nitrogen, lossis argon) lossis los ntawm kev qhia lwm yam khoom xws li TiH2, ZrH2, MgH2, CaCO3, thiab lwm yam ncaj qha rau hauv cov hlau matrix. Nyob rau hauv ob qho tib si, npuas yog tsim nyob rau saum npoo ntawm cov yaj thiab lawv tau daig thiab txias kom tsim voids.

Thaum siv txoj kev indirect foaming, cov hlau molten tsis ncaj qha foamed; Hloov chaw, qee qhov precursors xws li polymer foams los yog inorganic hais thiab tsawg-density hollow spheres yog siv los cam khwb cia hlau molten rau hauv ib tug npaus. Ua kua, thaum tso cai rau cov khoom loj ntawmhlau ua npuas ncaujnyob rau hauv daim ntawv, tsis muaj stability thiab controllability. Yog li ntawd, nyob ze cov duab net yog nyuaj rau tsim. Kev sib txawv ntawm cov ntaub ntawv uas tuaj yeem siv los ua foams los ntawm txoj kev no kuj muaj tsawg heev.

Solid-state foaming tuaj yeem txhais tau tias yog txheej txheem rau kev tsim cov hlau ua npuas ncauj uas ua kom cov txheej txheem ua haujlwm kub hauv qhov kub ntawm qhov kub ntawm cov khoom siv hauv paus. Hlau foams yog npaj los ntawm kev qhia tus neeg sawv cev tshuab ncaj qha mus rau hauv cov khoom sib xyaw hlau (intrinsic porosity) los yog los ntawm kev sib xyaw cov hmoov hlau nyob ib ncig ntawm lub pre-kho ib ntus template nrog voids (extrinsic porosity). Txawm hais tias cov txheej txheem solid-state tau tswj tau ntau dua, lawv raug nqi ntau. Tam sim no manufacturing industries tseem ceeb heev nyob rau hauv xaiv cov khoom rau manufacturability.

Hlau ua npuas ncaujyog ib yam tshiab ntawm cov khoom porous lub teeb uas muaj pores los yog voids nyob rau hauv ib tug khoom hlau. Cov pores feem ntau yog tsim nyob rau hauv lub hauv paus cov ntaub ntawv nyob rau hauv ib tug uncontrolled yam, raws li cov txheej txheem sib txawv los tsim ib tug heev randomized porous metallic qauv. Qhov ntim feem ntawm qhov tshwm sim qhov pores yog siab heev piv rau cov khoom siv hauv paus, uas ua rau cov khoom sib sib zog nqus. Ntxiv nrog rau nws lub teeb yuag, cov khoom siv muaj ntau yam ntawm lwm yam kev ua haujlwm zoo: lub zog siab-rau-hnyav piv thiab zoo heev kev co damping thiab lub suab nrov absorption peev xwm. Txhawm rau muab cov hlau ua npuas dej hauv txhua qhov kev lag luam, nws yuav tsum tau ua tib zoo sib xyaw nrog cov txheej txheem tsim khoom lag luam. Foamed hlau yog tus cwj pwm los ntawm kev nruj nruj thiab tsis tshua muaj zog tensile thiab yooj yim rau tawg nyob rau hauv load. Yog li ntawd, cov txheej txheem tsim cov pa tsis yooj yim rau kev ua cov duab dav dav ntawm hlau ua npuas ncauj fabrication. Raws li qhov tshwm sim, kev siv dav dav ntawm cov hlau foams yog hampered. Txoj kev ua laser yog ib txoj hauv kev uas siv cov khoom siv hluav taws xob zoo, lub laser, ua cov khoom siv tsis yog cov khoom siv thauj khoom.