Kuyini ukuncibilika kwe-vacuum induction?

Ukuncibilika kwe-vacuum kuyindlela yokuncibilikisa insimbi ne-alloy eyenziwa endaweni yevacuum.

Lobu buchwepheshe bungavimbela izinsimbi ezingavamile ukuthi zingangcoliswa umkhathi kanye nezinto eziphikisayo, futhi zinomsebenzi wokuhlanza nokuhlanza. Ngokuncibilika kwe-vacuum, izinsimbi zekhwalithi ephezulu nama-alloys anokuqukethwe kwegesi ephansi, ukufakwa okumbalwa, nokuhlukaniswa okuncane kungatholakala. Le ndlela ibalulekile ekutholeni izinto zensimbi ezihlanzekile nezisezingeni eliphezulu, ezifanele ikakhulukazi ama-alloys noma izinsimbi okunzima ukuzincibilikisa futhi ezidinga ubumsulwa obuphezulu kakhulu. Izindlela zokuncibilika kwe-vacuum zihlanganisa ukuncibilika kwe-electron beam, ukuncibilika kwe-vacuum induction, ukuncibilika kwesithando somlilo se-arc, kanye nokuncibilika kwesithando somlilo se-plasma. Isibonelo, ukuncibilika kwe-electron beam kusebenzisa imishayo yama-electron enamandla amakhulu ukuze kuqhunyiswe izinto ezincibilikisiwe, kuziguqule ngokushesha zibe amandla ashisayo futhi kuzincibilikise. Le ndlela ifanele ukuncibilika kobunzima obuphezulu kanye nama-alloys noma izinsimbi zokuhlanzeka okuphezulu kakhulu.

Ngaphezu kwalokho, ukuncibilika kwe-vacuum kusiza futhi ukuthuthukisa ukuqina, amandla okukhathala, ukumelana nokugqwala, ukusebenza kwe-high-temperature creep, kanye nokungena kazibuthe kwezinto zensimbi.

Ukuncibilika kwesithando somlilo se-vacuum kuyinqubo yokusebenzisa ukungeniswa kwe-electromagnetic ukukhiqiza ama-eddy currents kumakhondaktha ensimbi ngaphansi kwezimo ze-vacuum ukushisa impahla yesithando somlilo. Inezici zevolumu yekamelo elincane elincibilikayo, isikhathi esifushane sokupompa i-vacuum kanye nomjikelezo wokuncibilika, izinga lokushisa elikahle nokulawula ingcindezi, ukuphinda kusetshenziswe izinto eziguqukayo, nokulawula okunembile kokubunjwa kwe-alloy. Ngenxa yalezi zici ezingenhla, manje isithuthuke yaba umshini obalulekile wokukhiqiza ama-alloys akhethekile njengensimbi ekhethekile, ama-alloys anembayo, ama-alloys okushisa kagesi, ama-alloys asezingeni eliphezulu, nama-alloys angagqwali.

1. Yini i-vacuum?

Esitsheni esivaliwe, ngenxa yokuncipha kwenani lama-molecule egesi, ingcindezi ekhishwa ama-molecule egesi endaweni yeyunithi iyancipha. Ngalesi sikhathi, ingcindezi ngaphakathi esitsheni i yehlisa kunokucindezela okuvamile. Lolu hlobo lwesikhala esinegesi esingaphansi kunomfutho ojwayelekile lubizwa ngokuthi i-vacuum.

2. Uyini umgomo wokusebenza wesithando sokungenisa ivacuum?

Indlela eyinhloko ukusebenzisa i-electromagnetic induction ukuze ukhiqize okwamanje kushaje yensimbi ngokwayo, bese uncika ekuphikiseni ukushaja kwensimbi ngokwayo ukuguqula amandla kagesi abe amandla ashisayo ngokomthetho we-Joule Lenz, osetshenziselwa ukuncibilikisa izinsimbi.

3. Kwenziwa kanjani ukunyakaziswa kwe-electromagnetic esithandweni sokungenisa ivacuum?

Insimbi encibilikisiwe ku-crucible ikhiqiza amandla kagesi endaweni kazibuthe ekhiqizwa ikhoyili yokungeniswa. Ngenxa yomphumela wesikhumba, ama-eddy currents akhiqizwa insimbi encibilikisiwe aphikisana nesiqondiso se-current edlula ikhoyili yokungeniswa, okuholela ekuhlaselweni okuhlangene; Amandla anyanyekayo ensimbi encibilikisiwe ahlala ekhomba ngase-axis ye-crucible, futhi insimbi encibilikisiwe nayo iphushwa ibheke maphakathi ne-crucible; Ngenxa yokuthi ikhoyili ye-induction iyikhoyili emfushane enemiphumela emifushane emikhawulweni yomibili, amandla kagesi ahambisanayo kuzo zombili iziphetho zekhoyili yokungeniswa ayancipha, futhi ukusatshalaliswa kwamandla kagesi kuncane ekugcineni nangaphansi futhi kukhudlwana phakathi. Ngaphansi kwala mandla, uketshezi lwensimbi kuqala lusuka maphakathi luye eksisi ye-crucible, bese lugeleza luye phezulu naphansi luye phakathi nendawo. Lesi simo siyaqhubeka sijikeleza, sakha ukunyakaza okunamandla koketshezi lwensimbi. Ngesikhathi sokuncibilika kwangempela, isenzakalo soketshezi lwensimbi oluqhuma luye phezulu futhi lubheke phezulu naphansi phakathi nendawo ye-crucible lungaqedwa, olubizwa ngokuthi i-electromagnetic stirring.

4. Uyini umsebenzi wokunyakazisa kazibuthe?

① Ingasheshisa izinga lokusabela ngokomzimba namakhemikhali phakathi nenqubo yokuncibilikisa; ② Hlanganisa ukwakheka koketshezi lwensimbi encibilikisiwe; ③ Izinga lokushisa lensimbi encibilikisiwe ku-crucible livame ukuhambisana, okuholela ekuqedweni okuphelele kokusabela ngesikhathi sokuncibilika; ④ Umphumela wokunyakazisa unqoba umphumela wokucindezela kwawo okumile, ukuphenya amabhamuza ancibilikisiwe ekujuleni kwe-crucible endaweni ewuketshezi, kube lula ukuphuma kwegesi kanye nokunciphisa ukufakwa kwegesi okuqukethwe kwe-alloy Ukugqugquzela okunamandla kuthuthukisa ukuguguleka komshini kwensimbi encibilikisiwe ku-crucible, okuthinta ukuphila kwayo; ⑥ Sheshisa ukubola kwezinto eziphikisayo kuma-crucibles emazingeni okushisa aphezulu, okuholela ekungcolisweni kabusha kwe-alloy encibilikisiwe.

5. Iyini i-vacuum degree?

Idigri ye-vacuum imelela ubuncane begesi ngaphansi komfutho womoya owodwa, ngokuvamile ovezwa njengokucindezela.

6. Lithini izinga lokuvuza?

Izinga lokuvuza libhekisela enanini lokwenyuka kwengcindezi ngesikhathi seyunithi ngayinye ngemva kokuvalwa komshini wokuvala.

7. Uyini umphumela wesikhumba?

Umthelela wesikhumba ubhekisela kwinto yokusatshalaliswa okungalingani kwamanje esigabeni esiphambanayo sekhondatha (kubhekiselwa eshadini yesithando somlilo ekuncibilikiseni) lapho ukushintshashintsha kwamandla kudlula kuso. Ukuphakama kwamanje kokuminyana kwekhondatha, kwehla ukuminyana kwamanje maqondana nendawo.

8. Kuyini ukungeniswa kwe-electromagnetic?

Amandla ashintshayo adlula ocingweni futhi akhiqize indawo kazibuthe eshintshanayo eyizungezile, kuyilapho ukubeka intambo evaliwe endaweni kazibuthe eshintshayo kukhiqiza amandla ashintshanayo ngaphakathi kwentambo. Lesi simo sibizwa ngokuthi i-electromagnetic induction.

10. Yiziphi izinzuzo zokuncibilikisa isithando se-vacuum induction?

① Akukho ukungcoliswa komoya ne-slag, ingxubevange encibilikisiwe ihlanzekile futhi inezinga eliphezulu lokusebenza;

② Ukuncibilika kwe-vacuum kudala izimo ezinhle zokususa umoya, okuholela ekuqukethwe kwegesi ephansi kunsimbi encibilikisiwe ne-alloy;

③ Ngaphansi kwezimo ze-vacuum, izinsimbi azifakwa i-oxidized kalula;

④ Ukungcola (Pb, Bi, njll.) okulethwe izinto zokusetshenziswa kungahwamuka kusimo se-vacuum, okuholela ekuhlanzekeni kwempahla;

⑤ Ngesikhathi sokuncibilikiswa kwesithando somlilo se-vacuum, i-carbon deoxidation ingasetshenziswa, futhi umkhiqizo we-deoxygenation uyigesi, okuholela ekuhlanzekeni okuphezulu kwe-alloy;

⑥ Ingakwazi ukulungisa kahle futhi ilawule ukwakheka kwamakhemikhali;

⑦ Izinto ezibuyiswayo zingasetshenziswa.

11. Yiziphi izithiyo zokuncibilikisa isithando somlilo se-vacuum?

① Izinto zokusebenza ziyinkimbinkimbi, ziyabiza, futhi zidinga ukutshalwa kwezimali okukhulu;

② Ukunakekela okungalungile, izindleko eziphezulu zokuncibilikisa, kanye nezindleko eziphakeme uma kuqhathaniswa;

③ Ukungcola kwensimbi okubangelwa izinto eziphikisayo emibhodweni ngesikhathi sokuncibilika;

④ Iqoqo lokukhiqiza lincane, futhi umsebenzi wokuhlola mkhulu.

12. Yiziphi izimiso eziyisisekelo nezincazelo zamaphampu evacuum?

① Idigri ye-vacuum eyeqile: Inani elincane lokucindezela elizinzile (okungukuthi idigri ye-vacuum ezinzile) engatholwa ngemva kwesikhathi eside sokuthulula lapho i-inlet yepompo ye-vacuum ivalwa ibizwa ngokuthi i-vacuum degree enkulu yephampu.

② Izinga lokuphuma: Ivolumu yegesi ekhishwa iphampu ngesikhathi seyunithi ibizwa ngokuthi izinga lokumpompa lephampu yevacuum.

③ Ingcindezi enkulu yokukhipha: Inani eliphezulu lokucindezela lapho igesi ikhishwa khona endaweni yokukhipha umoya yepompo yevacuum phakathi nokusebenza okuvamile.

④ Ingcindezi yangaphambili: Inani eliphezulu lokucindezela elidinga ukugcinwa endaweni yokukhipha umoya yephampu yevacuum ukuqinisekisa ukusebenza okuphephile.

13. Ungakhetha kanjani uhlelo lwepompo ye-vacuum enengqondo?

① Izinga lokumpompa lephampu yevacuum lihambisana nokucindezela okuthile kokungena kwephampu yevacuum;

② Amaphampu kagesi, amaphampu ezimpande, namaphampu akhuthaza uwoyela awakwazi ukuphumela ngqo emkhathini futhi kufanele athembele empompini yesiteji esingaphambili ukuze asungule futhi agcine ingcindezi yangaphambili enqunyiwe ukuze isebenze ngokujwayelekile.

14. Kungani ama-capacitor edinga ukwengezwa kumasekhethi kagesi?

Ngenxa yebanga elikhulu phakathi kwekhoyili yokungeniswa nezinto zesithando somlilo, ukuvuza kazibuthe kubi kakhulu, i-flux kazibuthe ewusizo iphansi kakhulu, namandla asebenzayo aphezulu. Ngakho-ke, kuma-circuits capacitive, i-current ihola i-voltage. Ukuze unciphise ithonya le-inductance futhi uthuthukise isici samandla, kuyadingeka ukufaka inombolo efanelekile yeziqukathi zikagesi kumjikelezo, ukuze i-capacitor ne-inductor ikwazi ukuzwakala ngokufana, ngaleyo ndlela ithuthukise isici samandla sekhoyili yokungeniswa.

15. Zingaki izingxenye zemishini eyinhloko yesithando sokungenisa ivacuum?

Igumbi elincibilikayo, igumbi lokuthulula, isistimu ye-vacuum, uhlelo lokuphakela amandla.

16. Yiziphi izinyathelo zokunakekela i-vacuum system ngesikhathi sokuncibilikiswa?

① Izinga likawoyela nezinga likawoyela lephampu yevacuum kujwayelekile;

② Isikrini sokuhlunga sibuyiselwa emuva ngokujwayelekile;

③ Ukuvalwa kwevalvu ngayinye yokuhlukanisa kujwayelekile.

17. Yiziphi izinyathelo zokunakekela uhlelo lokuphakelwa kukagesi ngesikhathi senqubo yokuncibilikisa?

① Izinga lokushisa lamanzi okupholisa le-capacitor lijwayelekile;

② Izinga lokushisa likawoyela we-transformer lijwayelekile;

③ Izinga lokushisa lamanzi okupholisa lekhebula livamile.

18. Yiziphi izidingo zeziphambano zokuncibilika kwesithando se-vacuum induction?

① Inokuqina okushisayo okuphakeme ukugwema ukuqhekeka okubangelwa ukupholisa okusheshayo nokushisisa;

② Inokuqina okuphezulu kwamakhemikhali ukuvimbela ukungcoliswa kwe-crucible ngezinto eziphikisayo;

③ Ukuba nokumelana nomlilo okwanele kanye namandla esakhiwo asezingeni eliphezulu ukumelana namazinga okushisa aphezulu kanye nomthelela wempahla yesithando somlilo;

④ I-crucible kufanele ibe nokuminyana okuphezulu kanye nendawo yokusebenza ebushelelezi ukuze kuncishiswe indawo yokuxhumana phakathi kwe-crucible noketshezi lwensimbi, nokunciphisa izinga lokunamathela kwezinsalela zensimbi ebusweni be-crucible.

⑤ Inezici eziphakeme zokuhlukanisa;

⑥ Ukuncipha kwevolumu encane ngesikhathi senqubo yokucwilisa;

⑦ Inokuqina okuphansi futhi imelana kahle ne-hydration;

⑧ Impahla e-crucible inenani elincane lokukhishwa kwegesi.

⑨ I-crucible inezinsiza eziningi zezinto zokwakha namanani aphansi.

19. Ungathuthukisa kanjani ukusebenza kwezinga lokushisa eliphezulu kwama-crucibles?

① Yehlisa okuqukethwe kwe-CaO kanye nesilinganiso se-CaO/SiO2 kusihlabathi se-MgO ukuze kwehliswe inani lesigaba soketshezi futhi kukhuphule izinga lokushisa okukhiqizwa ngalo isigaba soketshezi.

② Thuthukisa ukuzinza kwezinhlamvu zekristalu.

③ Ukuze kuzuzwe isimo esihle se-recrystallization ongqimbeni olunamanzi, ukunciphisa i-porosity, ukunciphisa ububanzi bomngcele wokusanhlamvu, futhi kwakhiwe isakhiwo se-mosaic, kwakha inhlanganisela eqondile yezigaba eziqinile neziqinile, ngaleyo ndlela kuncishiswe imiphumela eyingozi yesigaba se-liquid.

20. Ungakhetha kanjani usayizi wejometri ofanele we-crucible?

① Ubukhulu bodonga lwe-crucible ngokuvamile bungu-1/8 kuya ku-1/10 wobubanzi be-crucible (eyakhiwe);

② Uketshezi lwensimbi lubalelwa ku-75% wevolumu ye-crucible;

③ I-engeli ka-R icishe ibe ngu-45 °;

④ Ubukhulu bephansi lesithando somlilo ngokuvamile izikhathi ezingu-1.5 zodonga lwesithando somlilo.

21. Yiziphi izinto ezinamathelayo ezivame ukusetshenziswa ezitsheni zokubopha amafindo?

① I-Organic matter: i-dextrin, i-pulp waste liquid, i-organic resin, njll;

② Izinto ezingaphili: i-sodium silicate, i-brine, i-boric acid, i-carbonate, ubumba, njll.

22. Uyini umsebenzi we-adhesive (H3BO3) we-knotting crucibles?

I-Boric acid (H3BO3) ingasusa wonke umswakama ngokufudumeza ngaphansi kuka-300 ℃ ngaphansi kwezimo ezijwayelekile, futhi ibizwa nge-boronic anhydride (B2O3).

① Emazingeni okushisa aphansi, enye i-MgO ne-Al2O3 ingancibilika ibe yi-B2O3 ewuketshezi ukuze yakhe uchungechunge lwemikhiqizo yoguquko, isheshise ukusakazeka kwesigaba esiqinile se-MgO · Al2O3 futhi ikhuthaze ukwenziwa kabusha kwekristalu, okubangela ungqimba olushisayo lwe-crucible ukuthi lwakheke emazingeni okushisa aphansi, ngaleyo ndlela kuncishiswe izinga lokushisa le-sintering.

② Ngokuthembela ekuncibilikeni nasekubopheni umphumela we-boric acid ezingeni lokushisa eliphakathi nendawo, isendlalelo se-semi sintered singaqiniswa noma amandla e-crucible ngaphambi kokunyuswa kwe-secondary sintering.

③ Esihlabathini se-magnesia esiqukethe i-CaO, ukusetshenziswa kwezibophezelo kungacindezela ukuguqulwa kwekristalu kwe-2CaO · SiO2 ngaphansi kuka-850 ℃.

23. Yiziphi izindlela ezehlukene zokubumba izimbambo?

Izindlela ezimbili.

① Ukwenziwa ngaphambilini ngaphandle kwesithando somlilo; Ngemva kokuxuba izinto zokusetshenziswa (i-magnesium ehlanganisiwe kagesi noma i-aluminium magnesium spinel refractory materials) ngesilinganiso esithile sosayizi wezinhlayiyana nokukhetha okunamathelayo okufanelekile, akhiwa ekubunjweni kwe-crucible ngokusebenzisa izinqubo zokudlidliza kanye ne-isostatic pressure. Umzimba we-crucible uyomiswa futhi ucutshungulwe ku-crucible eyenziwe ngaphambilini kuhhavini lokushisa eliphezulu lokushisa elinokushisa okuphezulu kokudubula okungu-≥ 1700 ℃ × 8 amahora.

② Ukushaya ngokuqondile ngaphakathi kwesithando somlilo; Engeza inani elifanele le-adhesive eqinile, njenge-boric acid, esilinganisweni esifanele sikasayizi wezinhlayiyana, hlanganisa ngokulinganayo, futhi usebenzise i-tamping ukuze ufeze ukugcwaliswa okuminyene. Ngesikhathi sokushisa, ama-microstructures ahlukene akhiwa amazinga okushisa ahlukene engxenye ngayinye.

24. Zingaki izingqimba ezakhiwe nge-sintering ye-crucible, futhi imuphi umthelela kwikhwalithi ye-crucible?

Isakhiwo se-sintering se-crucible sihlukaniswe izingqimba ezintathu: isendlalelo esincibilikayo, isendlalelo se-semi sintering, nesendlalelo esivulekile.

Isendlalelo se-Sintering: Ngesikhathi senqubo ye-ovini, usayizi wezinhlayiyana uthola ukubuyiswa kabusha. Ngaphandle kobukhulu bezinhlayiya zesihlabathi esimaphakathi ekugcineni kwezinga lokushisa eliphansi, isilinganiso sokuqala asikwazi ukubonwa nhlobo, futhi kuthulwa umfaniswano kanye nesakhiwo esihle. Imingcele yokusanhlamvu mincane kakhulu, futhi ukungcola kusakazwa kabusha emingceleni emisha yokusanhlamvu. Isendlalelo se-sintered igobolondo eliqinile elitholakala engxenyeni engaphakathi yodonga lwe-crucible, oluthinta ngokuqondile insimbi encibilikile futhi luthwala amandla ahlukahlukene, ngakho-ke lolu hlaka lubaluleke kakhulu ku-crucible.

Isendlalelo esixekethile: Ngesikhathi sokushisa, izinga lokushisa eliseduze nesendlalelo sokufakwa liphansi, futhi isihlabathi se-magnesium asikwazi ukucwiliswa noma ukuboshelwa isigaba sengilazi, sihlale sisesimweni esixekethile ngokuphelele. Lesi singqimba sitholakala engxenyeni engaphandle ye-crucible futhi sisebenzisa lezi zinhloso ezilandelayo: okokuqala, ngenxa yesakhiwo saso esixekethile kanye nokungahambi kahle kwe-thermal, ukushisa okudluliselwa odongeni lwangaphakathi lwe-crucible kuya ngaphandle kuyancishiswa, ukunciphisa ukulahlekelwa ukushisa, ukuhlinzeka nge-insulation, nokuthuthukisa ukusebenza kahle kokushisa ngaphakathi kwe-crucible; Okwesibili, ungqimba oluvulekile luphinde lube ungqimba oluvikelayo. Ngenxa yokuthi ungqimba lwe-sintered lwenze igobolondo futhi luhlangana ngqo nensimbi ewuketshezi, lujwayele ukuqhekeka. Uma isiqhekekile, insimbi ewuketshezi encibilikisiwe izophuma emfantwini, kanti ungqimba oluxekethile alujwayele ukuqhekeka ngenxa yesakhiwo sayo esixegayo. Uketshezi lwensimbi oluphuma kungqimba lwangaphakathi luvinjwe yilo, lunikeze ukuvikeleka kwendandatho yokuzwa; Okwesithathu, ungqimba oluxekethile luseyibhafa. Ngenxa yokuthi ungqimba lwe-sintered seluyigobolondo eliqinile, ukunwetshwa kwevolumu iyonke kanye nokufinyela kwenzeka lapho kushisa futhi kupholile. Ngenxa yesakhiwo esixegayo sesendlalelo esixekethile, sidlala indima yokuphazamisa ekushintsheni kwevolumu ye-crucible.

Isendlalelo esine-semi sintered (esaziwa nangokuthi isendlalelo soguquko): sitholakala phakathi kwesendlalelo esine-sintered kanye nesendlalelo esixekethile, sihlukaniswe izingxenye ezimbili. Eduze kwesendlalelo esisikiwe, ukungcola kuyancibilika futhi kusabalalise kabusha noma kuhlanganiswe nezinhlayiya zesihlabathi se-magnesium. Isihlabathi se-Magnesium sithola kabusha ingxenye, futhi izinhlayiya zesihlabathi ezinkulu zibonakala ziminyene kakhulu; Izingxenye eziseduze nongqimba oluvulekile zihlanganiswe ngokuphelele nge-adhesive. Isendlalelo esine-semi sintered sisebenza njengokubili isendlalelo esine-sintered kanye nesendlalelo esixekethile.

25. Ungakhetha kanjani uhlelo lwenqubo ye-ovini?

① Izinga lokushisa eliphezulu likahhavini: Uma ugqinsi longqimba lwe-insulation crucible lungu-5-10mm, ku-magnesia ehlanganisiwe kagesi, isendlalelo esihlanganisiwe sibala kuphela u-13-15% wogqinsi lwe-crucible uma kubhakwa ku-1800 ℃. Uma kubhakwa kuhhavini ongu-2000 ℃, kubalelwa ku-24-27%. Uma ucabangela amandla okushisa aphezulu e-crucible, kungcono ukuba nokushisa kwe-oven ephakeme, kodwa akulula ukuphakama kakhulu. Uma izinga lokushisa lingaphezu kuka-2000 ℃, lakha ikhekheba lezinyosi njengesakhiwo ngenxa yokuncishiswa kwe-magnesium oxide noma ukuncishiswa kwe-magnesium oxide ngekhabhoni, kanye nokuqiniswa kabusha kwe-magnesium oxide. Ngakho-ke, izinga lokushisa eliphezulu lehhavini kufanele lilawulwe ngaphansi kuka-2000 ℃.

② Izinga lokushisa: Esigabeni sokuqala sokushisa, ukuze kukhishwe kahle umswakama ezintweni eziphikisayo, ukufudumala okwanele kufanele kwenziwe. Ngokuvamile, izinga lokushisa kufanele lihambe kancane libe ngaphansi kuka-1500 ℃; Lapho izinga lokushisa lomlilo lifinyelela ngaphezu kuka-1500 ℃, isihlabathi se-magnesia esihlanganisiwe sikagesi siqala ukucwila. Ngalesi sikhathi, amandla aphezulu kufanele asetshenziselwe ukushisa ngokushesha kuze kufike ezingeni lokushisa eliphezulu elilindelekile lehhavini.

③ Isikhathi sokufakwa kwe-insulation: Ngemuva kokuthi izinga lokushisa lomlilo lifinyelele izinga lokushisa eliphakeme kakhulu likahhavini, ukwahlukanisa kufanele kwenziwe kulelo zinga lokushisa. Isikhathi sokufakelwa siyahlukahluka kuye ngokuthi uhlobo lwesithando somlilo kanye nezinto ezibonakalayo, njengemizuzu engu-15-20 ye-magnesium crucibles encane encibilika kagesi kanye nemizuzu engu-30-40 ye-magnesium crucibles kagesi encibilika enkulu.

Ngakho-ke, izinga lokushisa ngesikhathi sehhavini kanye nokubhaka ekushiseni okuphezulu kokubhaka kufanele kulungiswe ngokufanele