iindaba

Kutheni kuvela i-stomata?

1.1 Umngxuma womngxuma odityanisiweyo welaser ukwimo engazinzanga, kwaye ukuhamba komngxuma kunye nedama elinyibilikisiweyo kubukhali kakhulu.Umphunga wesinyithi ngaphakathi komngxuma uphuma ngaphandle kwaye ukhokelelai-vortex yomphungayenziwe ekuvulekeni komngxuma, oqengqelekayo igesi ekhuselayo (Ar) ingene ezantsi komngxuma, kwayeumngxuma uqhubela phambili, ezi gesi ezikhuselayo ziya kungena echibini elityhidiweyo ngendlela yamaqamza.Ngenxa yokunyibilika okuphantsi kakhulu kwe-Ar kunye nesantya sokupholisa ngokukhawuleza kwe-laser welding, amaqamza ashiywe kumthungo we-weld ngaphambi kokuba abaleke.ukwenza i-stomata.Ngaphezu koko, kwabayenziwe nguukukhuselwa kakubi ngexesha lenkqubo ye-welding ukuba i-nitrogen ihlasela i-pool etyhidiweyo evela ngaphandle, kunye nokunyibilika kwe-nitrogen kwintsimbi engamanzi yahluke kakhulu ekunyibilikeni kwe-nitrogen kwintsimbi eqinileyo.Ngoko ke kwiukupholisa kunye nokuqina kwesinyithi, ukunyibilika nitrogen kuncipha kunye nokuncipha lobushushu xa isinyithi pool etyhidiweyo lupholisiwe ukuya ekuqaleni crystallization kunokukhokelela ukwehla ngesiquphe ukunyibilika.Ngeli xesha isixa esikhulu serhasi iya kuwayenza amaqamza.Ukuba isantya esidadayo samaqamza singaphantsi kwesantya sekristale yesinyithi, iipores zenziwa.

Indlela ye-laser fusion welding icinezela i-porosity

1. Cindezela i-welding pores ngonyango lwangaphambili lwe-welding

Unyango lwangaphambili lwe-welding yindlela esebenzayo yokulawula i-metallurgical pores ye-aluminium alloy laser welds.Iindlela zonyango ezingaphezulu zinokwahlulwa zibeukucoca ngoomatshini kunye nokucoca iikhemikhalingokuqhelekileyo.

Emva kokuthelekisa, ukuthatha indlela yeekhemikhali yokujongana nomphezulu webhodi yokuvavanya (ukucoca isinyithi - ukuhlamba - ukuhlamba i-alkali - ukuhlamba - ukuhlamba - ukuhlamba - ukomisa) iyona nto ingcono.Phakathi kwabo, ukuhlamba kwe-alkali kususwe kubukhulu bomgangatho wezinto kunye nesisombululo esinamanzi se-25% ye-NaOH (i-sodium hydroxide), kwaye i-pickling yenziwa nge-20% HNO3 (i-nitric acid) + 2% HF (i-hydrogen fluoride). ) isisombululo samanzi sokunciphisa i-lye eshiyekileyo.Emva kokunyangwa komphezulu wepleyiti yovavanyo, ukuwelda kuqhutywa kwiiyure ezingama-24, kwaye indibano ngaphambi kokuba idityaniswe idityaniswe ngotywala obungenamanzi xa ipleyiti yovavanyo ifakwe ixesha elide emva konyango lovavanyo.

2. Ukuthintela i-welding pores nge-welding process parameters

Ukuqulunqwa kwe-weld porosity ayihambelani kuphela nomgangatho wonyango lwe-weldment surface, kodwa inxulumene neeparitha zenkqubo ye-welding.Impembelelo ye-welding parameters kwi-pores ye-weld ibonakala ngokungena kwe-weld, oko kukuthi, impembelelo yomlinganiselo womva wobubanzi be-weld kwi-pores.

Nguuvavanyosiyakwazi okokunokubonwa ukuba xa i-weld back wide ratio R i> 0.6, usasazo olugxininisiweyo lwe-chain pores kwi-weld lunokuphuculwa ngokufanelekileyo..Kwaye xa umva wobubanzi be-R yi-> 0.8, ubukho bee-pores ze-atmospheric kwi-weld bunokuphuculwa ngokufanelekileyo.Ngaphezu koko, intsalela ye-pores kwi-weld inokupheliswa kwinqanaba elikhulu.

3. Ukuthintela i-welding pores ngokukhetha ngokuchanekileyo igesi yokukhusela kunye nesantya sokuhamba

Ukukhethwa kwegesi yokukhusela kuchaphazela umgangatho, ukusebenza kakuhle kunye neendleko ze-welding ngokuthe ngqo.Kwinkqubo ye-laser welding, ukuvuthela okuchanekileyo kwegesi ekhuselayo kunokunciphisa i-weld pores ngokufanelekileyo.

Njengoko kuboniswe kumzobo ongentla, iAr (argon) kunye neHe (helium) isetyenziselwa ukukhusela ubuso be-weld.Kwinkqubo ye-aluminiyam i-alloy laser welding, i-Ar kunye Unayo idigri ezahlukeneyo ze-ionization ye-laser ezibangela ukubunjwa kwe-weld eyahlukeneyo.Kuyabonakala ukuba i-porosity ye-weld efunyenwe ngokusebenzisa i-Ar njengegesi yokukhusela ingaphantsi kwe-weld xa ekhethwa njengegesi yokukhusela.

Ngexesha elifanayo, kufuneka sihlawule ingqalelo kwinto yokuba ukuhamba kwegesi kuncinci kakhulu (<10L / min) kunye nenani elikhulu le-plasmas.eyenziwe yi-welding ayikwazi ukuvuthelwa ngaphandle,eya kwenzai-welding pool ayizinzanga kwaye amathuba okwakheka kwe-porosity anda.Ukuba isantya sokuhamba kwegesi ephakathi (malunga ne-15L / min) iplasma ilawulwa ngokufanelekileyo kwaye igesi ekhuselayo idlala umphumo omuhle wokuchasana ne-oxidation kwi-melten.idama,iya kuvelisa eyona porosity encinci.Ukuhamba kwegesi okugqithisileyo kuhamba kunye noxinzelelo olugqithisileyo lwegesi, ukwenzela ukuba inxalenye yegesi yokukhusela ixutywe ngaphakathi kwetanki, eyenza i-porosity iphakame.

Ukuchatshazelwa kukusebenza kwezinto ngokwazo, yonaandinakokuphephe ngokupheleleyo ukuba ukuwelda ngaphandle generatingi-porositykwinkqubo ye-welding.Into enokuyifeza kukuukunciphisa i-porosityizinga.