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Kungani kuvela i-stomata?

1.1 Ingaphakathi lembobo eshiselwe nge-laser isesimweni sokudlidliza esingazinzile, futhi ukugeleza kwembobo nechibi elincibilikisiwe kunamandla kakhulu.Umhwamuko wensimbi ongaphakathi kwembobo uqhuma ubheke ngaphandle bese uholela kui-vortex ye-steamkwakheka ekuvulekeni kwembobo, egingqa igesi evikelayo (Ar) ingene ngaphansi komgodi, futhiumgodi uya phambili, la magesi avikelayo azongena echibini elincibilikisiwe ngendlela yamagwebu.Ngenxa yokuncibilika okuphansi kakhulu kwe-Ar kanye nezinga lokupholisa ngokushesha le-laser welding, amabhamuza ashiywa emthungo wokushisela ngaphambi kokuthi abaleke.ukwakha i-stomata.Ngaphezu kwalokho, kwabaokubangelwaukuvikeleka okubi ngesikhathi senqubo yokushisela ukuthi i-nitrogen ihlasela ichibi elincibilikisiwe livela ngaphandle, kanye nokuncibilika kwe-nitrogen ensimbini ewuketshezi kuhluke kakhulu ekuncibilikeni kwe-nitrogen ensimbini eqinile.Ngakho-ke kuukupholisa nokuqiniswa kwensimbi, ukunyibilika kwe-nitrogen kuncipha ngokuncipha kwezinga lokushisa lapho insimbi yechibi elincibilikisiwe ipholiswa ekuqaleni kokucwebezela kungaholela ekwehleni okukhulu okungazelelwe kokuncibilika.Ngalesi sikhathi inani elikhulu legesi lizokwehlayenza ama-bubbles.Uma izinga elintantayo lamabhamuza lingaphansi kwezinga le-crystallization yensimbi, ama-pores akhiqizwa.

Indlela ye-laser fusion welding icindezela i-porosity

1. Cindezela ama-welding pores ngokuphathwa kwangaphambili kwe-welding surface

Ukwelashwa kwe-pre-welding surface kuyindlela ephumelelayo yokulawula izimbotshana ze-metallurgical ze-aluminium alloy laser welds.Izindlela zokwelapha ezingaphezulu zingahlukaniswa zibeukuhlanzwa kwemishini ngokomzimba nokuhlanza amakhemikhalingokuvamile.

Ngemva kokuqhathanisa, ukuthatha indlela yamakhemikhali ukubhekana nobuso bebhodi lokuhlola (ukuhlanza insimbi yokuhlanza - ukugeza - ukugeza i-alkali - ukugeza - ukugeza - ukugeza - ukomisa) kungcono kakhulu.Phakathi kwazo, ukugeza kwe-alkali kukhishwa kubukhulu bezinto ezibonakalayo ngesisombululo esinamanzi esingu-25% NaOH (sodium hydroxide), futhi ukuqoqwa kwenziwa nge-20% HNO3 (nitric acid) + 2% HF (hydrogen fluoride). ) isixazululo esinamanzi sokunciphisa i-lye esele.Ngemuva kokwelashwa okungaphezulu kwepuleti yokuhlola, ukushisela kwenziwa kungakapheli amahora angama-24, futhi umhlangano ngaphambi kokushisela uhlanganiswa kusulwe ngotshwala obungenamanzi lapho ipuleti lokuhlola lifakwa isikhathi eside ngemuva kokwelashwa kwepuleti yokuhlola.

2. Vimbela ama-pores welding ngemingcele yenqubo ye-welding

Ukwakheka kwe-weld porosity akuhlobene kuphela nekhwalithi yokwelashwa kwe-weldment surface, kodwa futhi kuhlobene nemingcele yenqubo yokushisela.Ithonya lamapharamitha we-welding kuma-pores we-weld ibonakala ngokuyinhloko ekungeneni kwe-weld, okungukuthi, ithonya lesilinganiso sobubanzi be-back weld kuma-pores.

Nguukuhlolasingakwazi lokhokuyabonakala ukuthi uma isilinganiso se-weld back wide wide ratio R singu-> 0.6, ukusatshalaliswa okugxilile kwezimbotshana zamaketango ku-weld kungathuthukiswa ngempumelelo..Futhi uma isilinganiso sobubanzi bangemuva R singu-> 0.8, ukuba khona kwezimbotshana zasemkhathini ku-weld kungathuthukiswa ngempumelelo.Ngaphezu kwalokho, izinsalela zama-pores ku-weld zingaqedwa ngezinga elikhulu.

3. Vimbela ama-pores welding ngokukhetha kahle ukuvikela igesi kanye nezinga lokugeleza

Ukukhethwa kwegesi yokuzivikela kuthinta izinga, ukusebenza kahle kanye nezindleko zokushisela ngokuqondile.Enqubweni ye-laser welding, ukushaywa kahle kwegesi yokuvikela kunganciphisa ama-pores weld ngempumelelo.

Njengoba kuboniswe esithombeni esingenhla, i-Ar (argon) kanye noHe (helium) isetshenziselwa ukuvikela ubuso be-weld.Enqubweni ye-aluminium alloy laser welding, i-Ar kanye ne-He has degrees ehlukene ye-ionization ye-laser okuholela ekwakhekeni kwe-weld ehlukene.Kungabonakala ukuthi i-porosity ye-weld etholwe ngokusebenzisa i-Ar njengegesi evikelayo ingaphansi kwe-weld lapho ekhethwa njengegesi elivikelayo.

Ngesikhathi esifanayo, kufanele futhi sinake iqiniso lokuthi ukugeleza kwegesi kuncane kakhulu (<10L/min) kanye nenani elikhulu lama-plasma.eyenziwe nge-welding ayikwazi ukushaywa umoya,okuzokwenzai-welding pool ayizinzile kanye namathuba okwakheka kwe-porosity anda.Uma izinga lokugeleza kwegesi elimaphakathi (cishe i-15L/min) i-plasma ilawulwa ngokuphumelelayo futhi igesi evikelayo idlala umphumela omuhle wokulwa ne-oxidation ekuncibilikeni.ichibi,izokhiqiza i-porosity encane.Ukugeleza kwegesi ngokweqile kuhambisana nokucindezela kwegesi ngokweqile, ukuze ingxenye yegesi evikelayo ihlanganiswe ngaphakathi kwethangi, okwenza i-porosity ikhuphuke.

Ithintwe ukusebenza kwento ngokwayo, yonaangekegwema ngokuphelele ukuthi i-welding ngaphandle kokukhiqizai-porosityohlelweni lokushisela.Engakufeza wukuukunciphisa i-porosityisilinganiso.