(1) Halayen brazing matsalolin da ke cikin graphite da lu'u-lu'u brazing polycrystalline sun yi kama da waɗanda aka ci karo da su a cikin brazing yumbu.Idan aka kwatanta da ƙarfe, solder yana da wahala a jika kayan graphite da lu'u-lu'u polycrystalline, kuma ƙimarsa na faɗaɗa thermal ya bambanta da na kayan gini na gabaɗaya.Biyu suna mai tsanani kai tsaye a cikin iska, kuma hadawan abu da iskar shaka ko carbonization zai faru lokacin da zafin jiki ya wuce 400 ℃.Don haka, dole ne a karɓi injin brazing, kuma matakin injin ba zai zama ƙasa da 10-1pa ba.Saboda ƙarfin duka biyu ba shi da yawa, idan akwai damuwa na thermal a lokacin brazing, fashewa na iya faruwa.Yi ƙoƙarin zaɓar ƙarfe mai filler brazing tare da ƙarancin haɓakar haɓakar zafi kuma sarrafa ƙimar sanyaya sosai.Tun da saman irin waɗannan kayan ba sauƙi ba ne a jika ta hanyar ƙarfe na brazing na yau da kullun, ƙaramin 2.5 ~ 12.5um lokacin farin ciki W, Mo da sauran abubuwan za'a iya ajiye su akan saman graphite da kayan polycrystalline lu'u-lu'u ta hanyar gyara shimfidar wuri (shafi mai laushi). , ion sputtering, plasma spraying da sauran hanyoyin) kafin brazing da samar da daidai carbide tare da su, ko high aiki brazing filler karafa za a iya amfani da.
Graphite da lu'u-lu'u suna da maki da yawa, waɗanda suka bambanta da girman barbashi, yawa, tsabta da sauran fannoni, kuma suna da halaye daban-daban na brazing.Bugu da kari, idan yawan zafin jiki na polycrystalline lu'u-lu'u kayan ya wuce 1000 ℃, da polycrystalline lalacewa rabo fara ragewa, da lalacewa rabo rage da fiye da 50% a lokacin da zazzabi ya wuce 1200 ℃.Don haka, lokacin da lu'u-lu'u na lu'u-lu'u, zazzabin brazing dole ne a sarrafa shi ƙasa da 1200 ℃, kuma matakin injin ba zai zama ƙasa da 5 × 10-2Pa ba.
(2) Zaɓin ƙarfe filler brazing ya dogara ne akan amfani da sarrafa saman.Lokacin da aka yi amfani da shi azaman abu mai jurewa zafi, za a zaɓi ƙarfe filler brazing tare da babban zafin brazing da kyakkyawan juriya na zafi;Don kayan da ke jure lalata sinadarai, an zaɓi karafa na filler brazing tare da ƙarancin zafin jiki da ingantaccen juriya na lalata.Ga graphite bayan surface metallization jiyya, m jan karfe solder da high ductility da kyau lalata juriya za a iya amfani da.tushen Azurfa da jan ƙarfe na tushen aiki mai solder suna da ingantaccen wettability da ruwa zuwa graphite da lu'u-lu'u, amma zafin sabis na haɗin gwiwa brazed yana da wahala ya wuce 400 ℃.Don kayan aikin graphite da kayan aikin lu'u-lu'u da aka yi amfani da su tsakanin 400 ℃ da 800 ℃, gindin zinari, tushe na palladium, tushe na manganese ko ƙarfe na tushen tushen titanium galibi ana amfani da su.Don gidajen abinci da aka yi amfani da su tsakanin 800 ℃ da 1000 ℃, za a yi amfani da ƙarfe na tushen nickel ko ma'aunin rawar soja.Lokacin da aka yi amfani da kayan aikin graphite sama da 1000 ℃, ana iya amfani da ƙarfe mai cike da ƙarfe mai tsafta (Ni, PD, Ti) ko ƙarafa mai cike da ƙarfe wanda ke ɗauke da molybdenum, Mo, Ta da sauran abubuwan da zasu iya ƙirƙirar carbide tare da carbon.
Don graphite ko lu'u-lu'u ba tare da jiyya na saman ba, ana iya amfani da karafa masu aiki a cikin tebur 16 don brazing kai tsaye.Yawancin waɗannan karafa na filler sune tushen binaryar titanium ko alloys na ternary.Titanium mai tsabta yana amsawa da ƙarfi tare da graphite, wanda zai iya samar da Layer na carbide mai kauri sosai, kuma ƙimar faɗaɗawar layinsa ta bambanta da na graphite, wanda ke da sauƙin samar da fasa, don haka ba za a iya amfani da shi azaman mai siyarwa ba.Bugu da ƙari na Cr da Ni zuwa Ti na iya rage ma'anar narkewa da inganta jimiri tare da yumbu.Ti wani allo ne na ternary, galibi ya ƙunshi Ti Zr, tare da ƙari na TA, Nb da sauran abubuwa.Yana da ƙananan ƙayyadaddun ƙayyadaddun faɗaɗa na layi, wanda zai iya rage damuwa na brazing.Gilashin ternary wanda ya ƙunshi Ti Cu ya dace da brazing na graphite da karfe, kuma haɗin gwiwa yana da juriya na lalata.
Tebur 16 brazing filler karafa don brazing kai tsaye na graphite da lu'u-lu'u
(3) Brazing tsari da brazing hanyoyin na graphite za a iya raba biyu Categories, daya ne brazing bayan surface metallization, da kuma sauran ne brazing ba tare da surface jiyya.Ko da wane irin hanyar da aka yi amfani da shi, za a riga an riga an riga an shirya welding kafin haɗuwa, kuma za a goge gurɓataccen kayan graphite mai tsabta da barasa ko acetone.A cikin yanayin ƙarfe na ƙarfe na ƙarfe, Layer na Ni, Cu ko Layer na Ti, Zr ko molybdenum disilicide za a yi amfani da shi a saman graphite ta hanyar fesa plasma, sannan a yi amfani da ƙarfe na tushen jan ƙarfe ko ƙarfe mai cike da azurfa don brazing. .brazing kai tsaye tare da mai aiki shine hanyar da aka fi amfani da ita a halin yanzu.Za a iya zaɓin zafin jiki na brazing bisa ga mai siyar da aka bayar a cikin tebur 16. Za'a iya danne mai siyar a tsakiyar haɗin haɗin gwiwa ko kusa da ƙarshen ɗaya.Lokacin yin brazing tare da ƙarfe tare da ƙaƙƙarfan ƙayyadaddun haɓakar haɓakar zafi, Mo ko Ti tare da ƙayyadaddun kauri ana iya amfani da shi azaman tsaka-tsakin buffer.Matsakaicin canji na iya haifar da nakasar filastik yayin dumama brazing, shawo kan zafin zafi da kuma guje wa fashewar hoto.Misali, Mo ana amfani da shi azaman haɗin gwiwa na canji don ɓacin rai na graphite da abubuwan hastelloyn.B-pd60ni35cr5 solder tare da kyakkyawan juriya ga narkakkar gishiri lalata da radiation ana amfani.Zazzabi na brazing shine 1260 ℃ kuma ana adana zafin jiki na 10min.
Lu'u lu'u lu'u-lu'u za a iya yi wa kai tsaye tare da b-ag68.8cu16.7ti4.5, b-ag66cu26ti8 da sauran masu siyarwa masu aiki.Za a gudanar da brazing a ƙarƙashin vacuum ko ƙananan kariyar argon.Zazzabi na brazing bai kamata ya wuce 850 ℃ ba, kuma yakamata a zaɓi ƙimar dumama mai sauri.Lokacin riƙewa a zafin jiki na brazing bai kamata ya yi tsayi da yawa ba (gaba ɗaya kusan 10s) don gujewa samuwar ci gaba na tic Layer a wurin dubawa.Lokacin brazing lu'u-lu'u da kuma gami karfe, roba interlayer ko low fadada gami Layer ya kamata a kara domin miƙa mulki don hana lalacewar da wuce kima da zafi danniya.Kayan aiki mai juyayi ko kayan aiki mai ban sha'awa don mashin ingantaccen mashin ɗin ana ƙera shi ta hanyar brazing, wanda ke lalata 20 ~ 100mg ƙaramin lu'u-lu'u akan jikin ƙarfe, kuma ƙarfin haɗin gwiwa na haɗin gwiwa na brazing ya kai 200 ~ 250mpa
Lu'u lu'u lu'u-lu'u ana iya murɗa shi ta hanyar harshen wuta, babban mita ko vacuum.Babban mitar brazing ko brazing na harshen wuta za a karɓi don lu'u-lu'u madauwari saw ruwan yankan ƙarfe ko dutse.Ag Cu Ti mai aiki brazing filler karfe tare da ƙarancin narkewar za a zaɓi.Za a sarrafa zafin jiki na brazing a ƙasa da 850 ℃, lokacin dumama ba zai daɗe da yawa ba, kuma za a karɓi ƙimar sanyaya jinkirin.Gilashin lu'u-lu'u na polycrystalline da ake amfani da su a cikin man fetur da hakowa na ƙasa ba su da ƙarancin yanayin aiki kuma suna ɗaukar nauyi mai yawa.Za'a iya zaɓar ƙarfe na tushen nickel brazing kuma za'a iya amfani da tsantsar foil na jan karfe azaman interlayer don injin brazing.Misali, 350 ~ 400 capsules Ф 4.5 ~ 4.5mm columnar polycrystalline lu'u-lu'u an brazed a cikin perforations na 35CrMo ko 40CrNiMo karfe don samar da yankan hakora.Vacuum brazing da aka karɓa, kuma injin digiri ba kasa da 5 × 10-2Pa, da brazing zafin jiki ne 1020 ± 5 ℃, da riƙe lokaci ne 20 ± 2min, da karfi ƙarfi na brazing hadin gwiwa ne mafi girma fiye da 200mpa.
A lokacin brazing, za a yi amfani da nauyin kai na walda don haɗuwa da matsayi gwargwadon yiwuwa don sanya ɓangaren ƙarfe ya danna graphite ko kayan polycrystalline a ɓangaren sama.Lokacin amfani da madaidaicin don sakawa, kayan haɓaka zai zama kayan da ke da haɓakar haɓakar thermal mai kama da na walda.
Lokacin aikawa: Juni-13-2022