Yin simintin amsawa
Tsarin narkewar amsawayumbu mai siffar silicon carbideTsarin samarwa ya haɗa da haɗa yumbu, haɗa wakilin shigar ruwa cikin sintering, haɗa sintering na amsawa da samfurin yumbu, shirya yumbu na silicon carbide da sauran matakai.
bututun sintering na silicon carbide
Na farko, kashi 80-90% na foda na yumbu (wanda aka haɗa da foda ɗaya ko biyu nafoda mai siliki carbideda kuma foda boron carbide), kashi 3-15% na foda tushen carbon (wanda aka haɗa da ɗaya ko biyu na carbon black resin da phenolic) da kuma kashi 5-15% na mannewa (phenolic resin, polyethylene glycol, hydroxymethyl cellulose ko paraffin) ana haɗa su daidai gwargwado ta amfani da injin niƙa ƙwallo don samun foda mai gauraya, wanda aka fesa aka busar da shi aka kuma yayyafa shi da granulated, sannan a matse shi a cikin mold don samun ƙaramin yumbu mai siffofi daban-daban.
Abu na biyu, ana gauraya foda na silicon kashi 60-80%, foda na silicon carbide kashi 3-10% da foda na boron nitride kashi 37-10% a ko'ina, sannan a matse su a cikin wani tsari don samun wani sintering flux inflation accelerate.
Sannan a haɗa ƙaramin yumbu da ƙaramin infiltrant ɗin da aka yi da simintin, sannan a ɗaga zafin zuwa 1450-1750℃ a cikin tanda mai injin tururi tare da matakin injin tururi na akalla 5 × 10-1 Pa don yin simintin da kuma adana zafi na tsawon awanni 1-3 don samun samfurin simintin da aka yi da simintin. Ana cire ragowar da ke shiga saman yumbun da aka yi da simintin ta hanyar taɓawa don samun takardar yumbu mai yawa, kuma ana kiyaye siffar asali ta simintin.
A ƙarshe, ana amfani da tsarin haɗa sinadarin amsawa, wato, sinadarin silicon mai ruwa ko kuma sinadarin silicon mai aiki a yanayin zafi mai yawa yana shiga cikin sinadarin yumbu mai ramuka wanda ke ɗauke da carbon a ƙarƙashin tasirin ƙarfin capillary, kuma yana yin aiki da carbon ɗin da ke ciki don samar da sinadarin silicon carbide, wanda zai faɗaɗa a girma, kuma sauran ramukan za a cika su da sinadarin silicon. Ɓoyayyen sinadarin yumbu mai ramuka zai iya zama sinadarin carbon ko silicon carbide/wanda aka haɗa da carbon. Ana samun na farko ta hanyar warkar da sinadarai da kuma yin pyrolyzing da resin na halitta, wani abu mai kama da rami da kuma wani abu mai narkewa. Ana samun na ƙarshe ta hanyar yin pyrolyzing da ƙwayoyin silicon carbide/kayan haɗin da aka haɗa da resin don samun kayan haɗin silicon carbide/kayan haɗin da aka haɗa da carbon, ko kuma ta hanyar amfani da α-SiC da foda na carbon a matsayin kayan farawa da kuma amfani da tsarin matsi ko allura don samun kayan haɗin.
Yin siminti ba tare da matsi ba
Tsarin simintin silicon carbide mara matsi za a iya raba shi zuwa simintin sintering mai ƙarfi da sintering mai ruwa-mataki. A cikin 'yan shekarun nan, binciken da aka gudanar kanyumburan silicon carbideA gida da ƙasashen waje, an fi mai da hankali kan yin simintin ruwa-mataki. Tsarin shirya yumbu shine: niƙa kayan ƙwallo iri-iri -> feshi granulation -> busasshen matsi -> ƙarfafa jiki kore -> simintin vacuum.
Kayayyakin silicon carbide marasa matsi
Sai a zuba sassa 96-99 na garin silicon carbide ultrafine (50-500nm), sassa 1-2 na garin boron carbide ultrafine (50-500nm), sassa 0.2-1 na nano-titanium boride (30-80nm), sassa 10-20 na resin phenolic mai narkewa a ruwa, da sassa 0.1-0.5 na mai watsawa mai inganci a cikin injin niƙa ƙwallon don niƙa ƙwallon da haɗawa na tsawon awanni 24, sannan a zuba gaurayen slurry a cikin ganga don juyawa na tsawon awanni 2 don cire kumfa a cikin slurry.
Ana fesa cakuda da ke sama a cikin hasumiyar granulation, kuma ana samun foda granulation mai kyau a cikin yanayin barbashi, ruwa mai kyau, kunkuntar rarraba barbashi da matsakaicin danshi ta hanyar sarrafa matsin lamba na feshi, zafin shigar iska, zafin fitar iska da girman barbashi na feshi. Canza mitar centrifugal shine 26-32, zafin shigar iska shine 250-280℃, zafin fitar iska shine 100-120℃, kuma matsin lamba na slurry shine 40-60.
Ana sanya foda mai siffar da ke sama a cikin wani siminti mai siffar carbide don matsewa don samun jiki mai launin kore. Hanyar matsewa ita ce matsi mai kusurwa biyu, kuma tan ɗin matsin lamba na kayan aikin injin shine tan 150-200.
Ana sanya jikin kore da aka matse a cikin tanda don busarwa da kuma warkewa don samun jiki kore mai ƙarfi na jiki kore.
An sanya jikin kore mai laushi a cikingraphite Cruciblesannan a shirya shi da kyau kuma a tsare, sannan a sanya graphite crucible tare da jikin kore a cikin tanda mai zafi don yin wuta. Zafin wutar shine 2200-2250℃, kuma lokacin rufewa shine awanni 1-2. A ƙarshe, ana samun yumbu mai simintin silicon carbide mai ƙarfi wanda ba shi da matsin lamba.
Tsarin sintering mai ƙarfi
Tsarin simintin silicon carbide mara matsi za a iya raba shi zuwa simintin simintin solid-phase da simintin ruwa-phase. Simintin ruwa-phase yana buƙatar ƙara ƙarin simintin simintin, kamar ƙarin Y2O3 binary da ternary, don yin SiC da kayan haɗinsa suna samar da simintin ruwa-phase da kuma cimma yawan danshi a ƙananan zafin jiki. Hanyar shirya simintin simintin silicon carbide mai ƙarfi-phase ya haɗa da haɗa kayan aiki, feshi granulation, molding, da kuma simintin vacuum. Tsarin samarwa na musamman shine kamar haka:
Ana sanya kashi 70-90% na submicron α silicon carbide (200-500nm), 0.1-5% na boron carbide, 4-20% na resin, da 5-20% na Organic binder a cikin mahaɗin kuma a ƙara da ruwa mai tsabta don haɗawa da ruwa. Bayan awanni 6-48, ana ratsa gaurayen slurry ta cikin sieve na raga na 60-120;
Ana fesa sinadarin slurry ta hanyar fesawa ta hanyar amfani da hasumiyar fesawa. Zafin shiga na hasumiyar fesawa shine 180-260℃, kuma zafin fita shine 60-120℃; yawan kayan granulated shine 0.85-0.92g/cm3, ruwa shine 8-11s/30g; ana tace kayan granulated ta hanyar sieve na raga na 60-120 don amfani daga baya;
Zaɓi mold bisa ga siffar samfurin da ake so, ɗora kayan da aka yi wa granulated a cikin ramin mold, kuma yi molding zafin ɗaki a matsin lamba na 50-200MPa don samun jiki kore; ko sanya jikin kore bayan molding a cikin na'urar matsi ta isostatic, yi matsi ta isostatic a matsin lamba na 200-300MPa, kuma sami jiki kore bayan dannawa ta biyu;
Sanya jikin kore da aka shirya a matakan da ke sama a cikin tanda mai cire hayaki don yin sintering, kuma wanda ya cancanta shine yumbu mai hana harsashi na silicon carbide da aka gama; a cikin tsarin sintering da ke sama, da farko ku fitar da tanda mai cire hayaki, kuma lokacin da matakin injin ya kai 3-5 × 10-2 Bayan Pa, ana tura iskar gas mai hana hayaki zuwa cikin tanda mai cire hayaki zuwa matsin lamba na yau da kullun sannan a dumama ta. Alaƙar da ke tsakanin zafin jiki da lokaci shine: zafin ɗaki zuwa 800℃, awanni 5-8, adana zafi na awa 0.5-1, daga 800℃ zuwa 2000-2300℃, awanni 6-9, adana zafi na awa 1 zuwa 2, sannan a sanyaya da tanda sannan a sauke zuwa zafin ɗaki.
Tsarin microstructure da iyakar hatsi na silicon carbide da aka simintin a matsin lamba na al'ada
A takaice, yumbu da aka ƙera ta hanyar amfani da tsarin matsewa mai zafi suna da ingantaccen aiki, amma farashin samarwa ma yana ƙaruwa sosai; yumbu da aka shirya ta hanyar amfani da sintering mara matsi suna da buƙatun kayan masarufi mafi girma, zafin sintering mai yawa, manyan canje-canje a girman samfura, tsari mai rikitarwa da ƙarancin aiki; samfuran yumbu da aka samar ta hanyar amfani da sintering suna da yawan yawa, kyakkyawan aikin hana ballistic, da ƙarancin farashin shiri. Tsarin shirye-shiryen sintering daban-daban na sintering na sintering na silica carbide suna da nasu fa'idodi da rashin amfani, kuma yanayin aikace-aikacen zai bambanta. Mafi kyawun tsari shine zaɓar hanyar shiri mai dacewa bisa ga samfurin kuma nemo daidaito tsakanin ƙarancin farashi da babban aiki.
Lokacin Saƙo: Oktoba-29-2024