Laser Material Kudyidzana - Keyhole Effect

Kuumbwa uye kukura kwe keyholes:

 

Keyhole tsananguro: Kana iyo radiation irradiance yakakura kupfuura 10 ^ 6W/cm ^ 2, pamusoro pechinhu chinonyunguduka uye chinobuda pasi pechiito chelaser.Kana iyo evaporation kumhanya yakakura zvakakwana, iyo inogadzirwa vapor recoil pressure inokwana kukunda kunetsa kwepasi uye giravhiti yemvura yesimbi yemvura, nekudaro ichibvisa imwe yesimbi yemvura, zvichiita kuti dziva rakanyungudutswa panzvimbo yekukurudzira rinyure nekuumba makomba madiki. ;Chiedza chechiedza chinobata zvakananga pasi pegomba diki, zvichiita kuti simbi iwedzere kunyunguduka uye kuita gasify.High pressure steam inoramba ichimanikidza simbi yemvura iri pasi pegomba kuti iyerere yakananga kunharaunda yedziva rakanyungudutswa, ichiwedzera kudzika buri diki.Izvi zvinoenderera mberi, zvichizopedzisira zvaita buri rekiyi seburi musimbi yemvura.Kana iyo simbi vapor pressure inogadzirwa nelaser beam mugomba diki inosvika pakuenzana nekutsikirira kwepasi uye kusimba kwesimbi yemvura, gomba diki harichadzika uye rinogadzira gomba rakadzika rakadzika, iro rinonzi "gomba diki mhedzisiro" .

Sezvo laser beam inofamba ichienda kune workpiece, kaburi kadiki kanoratidza kuseri kwakakombama kumberi uye nekakona kakarerekera kwakatenderedzwa kuseri.Mupendero wepamberi wegomba diki inzvimbo yekuita yelaser, ine tembiricha yakakwira uye yakakwira mhute yekumanikidza, nepo tembiricha iri kumucheto kumashure kwakadzikira uye mhute yekumanikidza idiki.Pasi pekumanikidzwa uku uye musiyano wetembiricha, mvura yakanyungudutswa inoyerera ichitenderedza gomba diki kubva kumberi kuenda kumucheto kumashure, ichigadzira vortex kumucheto kumashure kwegomba diki, uye pakupedzisira inoomesa kumucheto kumashure.The dynamic state of the keyhole inowanikwa kuburikidza nelaser simulation uye chaiyo welding inoratidzwa mumufananidzo uri pamusoro, The morphology yemakomba maduku uye kuyerera kwemvura yakanyunguduka yakakomberedza panguva yekufamba nekumhanya kwakasiyana.

Nekuda kwekuvapo kwemakomba madiki, iyo laser beam simba inopinda mukati meiyo zvinhu, ichigadzira iyi yakadzika uye yakamanikana weld seam.Iyo yakajairika cross-sectional morphology ye laser yakadzika yekupinda weld musono inoratidzwa mumufananidzo uri pamusoro.Kudzika kwekupinda kwemusono we weld kuri pedyo nekudzika kwegomba rekiyi (kunyatsojeka, iyo metallographic layer inosvika 60-100um yakadzika kupfuura keyhole, imwe shoma yemvura layer).Iyo yakakwirira iyo laser simba density, iyo yakadzika buri diki, uye yakakura kudzika kwekupinda kweiyo weld seam.Mune yakakwirira-simba laser welding, iyo yakanyanya kudzika kusvika kuhupamhi chiyero cheiyo weld seam inogona kusvika 12: 1.

Kuongororwa kwekutorwa kweLaser simbanepaburi rekiyi

Pamberi pekuumbwa kwemaburi madiki uye plasma, simba re laser rinonyanya kuendeswa kune mukati meiyo workpiece kuburikidza nekupisa kwekushisa.Iyo welding process ndeye conductive welding (ine kudzika kwekupinda kweisingasviki 0.5mm), uye chiyero chekunyudza chelaser chiri pakati pe25-45%.Kana iyo kiyi yakaumbwa, simba re laser rinonyanya kunyudzwa nemukati meiyo workpiece kuburikidza nekiyi hole maitiro, uye welding process inova yakadzika yekupinda welding (ine kudzika kwekupinda kweinopfuura 0.5mm), Iyo yekunyudza inogona kusvika pamusoro pe60-90%.

Iyo keyhole mhedzisiro inoita basa rakakosha zvakanyanya mukusimudzira kunyura kwelaser panguva yekugadzirisa senge laser welding, kucheka, uye kuchera.Iyo laser beam inopinda mugomba rekiyi inenge yanyatso kunyudzwa kuburikidza neakawanda maratidziro kubva paburi remadziro.

Zvinowanzotendwa kuti simba rekunyudza mashandiro e laser mukati mekiyi hole rinosanganisira maitiro maviri: reverse absorption uye Fresnel absorption.

Pressure balance mukati mekiyi hole

Munguva ye laser yakadzika yekupinda welding, zvinhu zvinopinda zvakanyanya vaporization, uye kuwedzera kudzvanywa kunogadzirwa nepamusoro-tembiricha chiutsi chinodzinga simbi yemvura, ichigadzira maburi madiki.Pamusoro peiyo mhute yekumanikidza uye ablation pressure (inozivikanwawo se evaporation reaction force kana recoil pressure) yechinhu, kune zvakare kudzvanya kwepamusoro, fluid static pressure inokonzerwa negiravhiti, uye fluid dynamic pressure inogadzirwa nekuyerera kwezvinhu zvakanyungudutswa mukati me. gomba duku.Pakati pemadzvinyiriro aya, mhepo chete yemhepo inochengetedza kuvhurika kwegomba diki, nepo mamwe masimba matatu achivavarira kuvhara gomba diki.Kuti uchengetedze kugadzikana kwechivharo chekiyi panguva yekugadzira welding, iyo vapor pressure inofanira kunge yakakwana kukunda kumwe kupikisa uye kubudirira kuenzana, kuchengetedza kugadzikana kwenguva refu kwekiyi.Kuti zvive nyore, zvinotendwa kuti mauto anoshanda pamadziro ekiyi anonyanya kudzvanywa (metal vapor recoil pressure) uye kushushikana kwepasi.

Kusagadzikana kwe Keyhole

 

Background: Laser inoshanda pamusoro pezvinhu, zvichiita kuti simbi yakawanda inyunguduke.Iyo recoil yekumanikidza inotsikirira pasi padziva rakanyungudutswa, ichigadzira makiyi uye plasma, zvichikonzera kuwedzera kwekunyungudika kudzika.Munguva yekufamba, iyo laser inorova kumberi kwemadziro ekiyi, uye chinzvimbo icho laser inobata zvinhu zvinokonzeresa evaporation yechinhu.Panguva imwecheteyo, kiyi yemadziro inosangana nekurasikirwa kukuru, uye evaporation ichaita kudzoreredza kudzvanya kunotsikirira pasi pesimbi yemvura, zvichiita kuti madziro emukati megomba rekiyi atendeuke achidzika pasi uye kutenderera pasi pegomba rekiyi akananga kune. seri kwedziva rakanyungudutswa.Nekuda kwekuchinja kwechidziva chemvura yakanyungudutswa kubva kumadziro epamberi kuenda kumadziro ekumashure, vhoriyamu mukati megomba rekiyi inogara ichichinja, Kudzvanywa kwemukati kwegomba rekiyi kunochinjawo zvinoenderana, izvo zvinotungamira mukushandurwa kwehuwandu hweplasma yakapfapfaidzwa kunze. .Shanduko yevhoriyamu yeplasma inotungamira mukuchinjika mukudzivirira, kudzoreredza, uye kutorwa kwelaser simba, zvichikonzera shanduko musimba relaser inosvika pamusoro pezvinhu.Iyo yese maitiro ine simba uye nguva nenguva, inozopedzisira yaita kuti sawtooth yakaumbwa uye wavy simbi ipinde, uye hapana yakatsetseka yakaenzana yekupinda weld, Iyo iri pamusoro apa iratidziro yepakati-chikamu chepakati che weld inowanikwa nelongitudinal yekucheka yakafanana pakati pe weld, pamwe nekuyera-chaiyo-nguva kuyerwa kweiyo keyhole kudzika kusiyanisa neIPG-LDD sehumbowo.

Kuvandudza kugadzikana kwekutungamira kwegomba rekiyi

Munguva yelaser yakadzika yekupinda welding, kugadzikana kwegomba diki kunogona chete kuve nechokwadi nekusimba kwesimba rekumanikidza kwakasiyana mukati megomba.Nekudaro, kutorwa kwelaser simba nemadziro egomba uye kubuda kwezvinhu, ejection yesimbi mhute kunze kwegomba diki, uye kuenda mberi kwegomba diki nedziva rakanyungudutswa zvese zvakanyanya uye nekukurumidza maitiro.Pasi pemamwe mamiriro ezvinhu, pane dzimwe nguva panguva yekugadzira welding, pane mukana wekuti kugadzikana kwegomba duku kunogona kuvhiringidzwa munzvimbo dzemunharaunda, zvichiita kuti kuve nekuremara kwewelding.Iyo yakajairika uye yakajairika ndiyo diki pore mhando porosity defects uye spatter inokonzerwa nekiyi kudonha;

Saka sei kudzikamisa kiyi hole?

Kuchinja kwe keyhole fluid kunenge kwakaoma uye kunosanganisira zvinhu zvakawandisa (tembiricha, nzvimbo inoyerera, simba remagetsi, optoelectronic physics), iyo inogona kungopfupikiswa muzvikamu zviviri: hukama huri pakati pehutano hwepamusoro uye simbi vapor recoil pressure;Iyo recoil kudzvanywa kwesimbi vapor inoshanda zvakananga pakugadzirwa kwemakiyi, ayo ane hukama zvakanyanya nekudzika uye huwandu hwemakiyi.Panguva imwecheteyo, sechinhu chega chinokwira kumusoro chesimbi mhute mukugadzira welding, zvakare yakabatana zvakanyanya nekuitika kwe spatter;Kudzvinyirirwa kwepamusoro kunokanganisa kuyerera kwedziva rakanyungudutswa;

Saka yakagadzikana laser welding process inoenderana nekuchengetedza kugovera gradient yekushushikana kwepasi mudziva rakanyungudutswa, pasina kuwedzeredza kushanduka.Kushushikana kwepamusoro kune hukama nekugovera tembiricha, uye kugovera tembiricha kune hukama nekupisa sosi.Naizvozvo, composite kupisa sosi uye swing welding zvinogona tekinoroji mafambiro eyakagadzika welding process;

Iyo simbi vapor uye keyhole vhoriyamu inoda kuterera kune iyo plasma mhedzisiro uye saizi yekuvhura kiyi yekuvhura.Iyo yakakura kuvhura, hombe buri rekiyi, uye kusachinja-chinja kusingatarisike munzvimbo yepasi pedziva rekunyunguduka, izvo zvine kashongedzo kadiki pahole yehole yevhoriyamu uye shanduko yemukati mukati;Saka inogadziriswa ring mode laser (annular spot), laser arc recombination, frequency modulation, nezvimwewo ndiwo mafambiro anogona kuwedzerwa.

 


Nguva yekutumira: Zvita-01-2023