Reaction sintering
The reaction sinteringsilicon carbide ceramickugadzirwa kwemaitiro kunosanganisira ceramic compacting, sintering flux infiltration agent compacting, reaction sintering ceramic chigadzirwa kugadzirira, silicon carbide huni kugadzirira ceramic uye mamwe matanho.
Reaction sintering silicon carbide nozzle
Kutanga, 80-90% yekeramic poda (inoumbwa neimwe kana maviri poda yesilicon carbide podauye boron carbide powder), 3-15% yekabhoni source powder (inoumbwa nekabhoni imwe chete kana mbiri dzekabhoni nhema uye phenolic resin) uye 5-15% ye molding agent (phenolic resin, polyethylene glycol, hydroxymethyl cellulose kana parafini) inosanganiswa zvakaenzana. kushandisa chigayo chebhora kuwana hupfu hwakavhenganiswa, inopfapfaidzwa yakaomeswa uye ine granulated, uye yobva yatsikwa muforoma kuti iwane ceramic compact ine dzakasiyana siyana. shapes.
Chechipiri, 60-80% silicon poda, 3-10% silicon carbide poda uye 37-10% boron nitride poda inosanganiswa zvakaenzana, uye inotsikirirwa muforoma kuti iwane sintering flux infiltration agent compact.
Iyo ceramic compact uye iyo sintered infiltrant compact inoiswa pamwe chete, uye tembiricha inosimudzwa kusvika 1450-1750 ℃ muchoto chevacuum ine vacuum degree isingasviki 5 × 10-1 Pa yekupisa uye kuchengetedza kupisa kwe1-3. maawa ekuwana reaction sintered ceramic chigadzirwa. Iyo infiltrant yakasara pamusoro peiyo sintered ceramic inobviswa nekudzvanya kuti iwane dense ceramic sheet, uye chimiro chepakutanga chekombiki chinochengetwa.
Chekupedzisira, iyo reaction sintering process inogamuchirwa, kureva, liquid silicon kana silicon alloy ine reaction chiitiko pakupisa kwakanyanya inopinda mukati me porous ceramic blank ine kabhoni pasi pechiito che capillary force, uye inopindirana nekabhoni irimo kuti igadzire silicon carbide, iyo. ichawedzera muhuwandu, uye ma pores akasara anozadzwa ne elemental silicon. Iyo porous ceramic isina chinhu inogona kuve yakachena kabhoni kana silicon carbide/carbon-based composite zvinhu. Iyo yekutanga inowanikwa necatalytically kurapa uye pyrolyzing organic resin, pore yekare uye solvent. Iyo yekupedzisira inowanikwa ne pyrolyzing silicon carbide particles / resin-based composite zvinhu kuwana silicon carbide/carbon-based composite zvinhu, kana kushandisa α-SiC uye kabhoni poda sekutanga zvinhu uye kushandisa kudzvanya kana jekiseni kuumba maitiro kuti uwane iyo inoumbwa. zvinhu.
Pressureless sintering
Iyo isina kudzvanywa sintering process yesilicon carbide inogona kukamurwa kuita solid-phase sintering uye liquid-phase sintering. Mumakore achangopfuura, tsvakurudzo pamusorosilicon carbide ceramicskumba nekune dzimwe nyika yakanyanya kutarisisa pane liquid-phase sintering. Iyo Ceramic kugadzirira maitiro ndeiyi: yakasanganiswa zvinhu bhora kugaya-> spray granulation-> yakaoma kudzvanya-> green body solidification-> vacuum sintering.
Pressureless sintered silicon carbide zvigadzirwa
Wedzera 96-99 zvikamu zvesilicon carbide ultrafine powder (50-500nm), 1-2 zvikamu zve boron carbide ultrafine powder (50-500nm), 0.2-1 zvikamu zve nano-titanium boride (30-80nm), 10-20 zvikamu yemvura-soluble phenolic resin, uye 0.1-0.5 zvikamu zvepamusoro-kushanda dispersant kune chigayo chebhora chekugaya bhora uye kusanganisa kwemaawa makumi maviri nemana, uye isa slurry yakasanganiswa mudhiramu yekusanganisa yekukurudzira kwemaawa maviri kuti ubvise mabubble mune slurry.
Musanganiswa wepamusoro unopfapfaidzwa mukati meiyo granulation tower, uye iyo granulation poda ine yakanaka particle morphology, yakanaka fluidity, yakatetepa particle yekugovera huwandu uye hunyoro hunyoro hunowanikwa nekudzora kupfapfaidza kupfapfaidza, tembiricha yekupinza mhepo, tembiricha yekubuda kwemhepo uye saizi yespray sheet. Iyo centrifugal frequency conversion ndeye 26-32, tembiricha yekupinza mhepo i250-280 ℃, tembiricha yekubuda kwemhepo iri 100-120 ℃, uye slurry inlet pressure iri 40-60.
Iyo yepamusoro granulation poda inoiswa mune simende carbide mold yekutsikirira kuwana muviri wakasvibira. Iyo yekutsikirira nzira ndeye bidirectional kudzvanywa, uye muchina chishandiso kumanikidza tonnage ndeye 150-200 matani.
Muviri wegirinhi wakadzvanywa unoiswa muhovhoni yekuomeswa nekuomeswa kuti uwane muviri wegirinhi une simba rakasvibira remuviri.
Muviri wegirinhi wakarapwa pamusoro unoiswa mu agraphite crucibleuye yakarongedzwa zvakanyatsonaka uye zvakatsvinda, uye ipapo girafu crucible ine yakasvibira muviri inoiswa mune yakakwira-tembiricha vacuum sintering muchoto wekupfura. Iyo tembiricha yekupisa ndeye 2200-2250 ℃, uye nguva yekudzivirira ndeye 1-2 maawa. Pakupedzisira, yakakwirira-inoshanda isina kudzvanywa sintered silicon carbide ceramics inowanikwa.
Solid-phase sintering
Iyo isina kudzvanywa sintering process yesilicon carbide inogona kukamurwa kuita solid-phase sintering uye liquid-phase sintering. Liquid-phase sintering inoda kuwedzerwa kwe sintering additives, senge Y2O3 mabhinari uye ternary additives, kugadzira SiC uye zvinhu zvayo zvinoumbwa zvivepo mvura-phase sintering uye kuwana densification pane yakaderera tembiricha. Iyo nzira yekugadzirira yakasimba-chikamu sintered silicon carbide ceramics inosanganisira kusanganiswa kwezvinhu zvakabikwa, spray granulation, kuumba, uye vacuum sintering. Iyo chaiyo yekugadzira maitiro ndeaya anotevera:
70-90% ye submicron α silicon carbide (200-500nm), 0.1-5% ye boron carbide, 4-20% ye resin, uye 5-20% ye organic binder inoiswa mumusanganisi uye inowedzerwa nemvura yakachena yekunyorova. kusanganisa. Mushure memaawa 6-48, slurry yakasanganiswa inopfuudzwa ne 60-120 mesh sieve;
Iyo sieved slurry inopfapfaidza granulated kuburikidza nespray granulation tower. Tembiricha yekupinza yespray granulation tower ndeye 180-260 ℃, uye tembiricha yekubuda ndeye 60-120 ℃; iyo yakawanda density ye granulated material ndeye 0.85-0.92g/cm3, fluidity is 8-11s/30g; iyo granulated material inosefa kuburikidza ne 60-120 mesh sieve kuti ishandiswe gare gare;
Sarudza mold inoenderana neinodiwa chigadzirwa chimiro, takura iyo granulated zvinhu mugomba, uye ita tembiricha yekumisikidza yekamuri pakumanikidza kwe50-200MPa kuti uwane muviri wakasvibira; kana kuisa muviri wakasvibira mushure mekumanikidza kuumbwa kuita isostatic yekutsikirira mudziyo, ita isostatic kudzvanya pakumanikidza kwe200-300MPa, uye uwane muviri wakasvibira mushure mekudzvanya kwechipiri;
Isa muviri wakasvibira wakagadzirirwa mumatanho ari pamusoro muchoto chevacuum sintering yekupisa, uye iyo inokwanisa ndiyo yakapedzwa silicon carbide bulletproof ceramic; mune iri pamusoro apa sintering process, tanga wabvisa muchoto unopisa, uye kana iyo vacuum degree yasvika 3-5 × 10-2 Mushure mePa, iyo inert gasi inopfuudzwa muchoto chekunyungudutsa kune yakajairwa kumanikidza uye yozopisa. Hukama huri pakati pekupisa tembiricha nenguva ndeiyi: tembiricha yekamuri kusvika 800 ℃, maawa 5-8, kuchengetedza kupisa kweawa 0.5-1, kubva 800 ℃ kusvika 2000-2300 ℃, maawa 6-9, kuchengetedza kupisa kweawa 1 kusvika 2, uye wozotonhodzwa nechoto uye ndokudonhera kune tembiricha yekamuri.
Microstructure uye zviyo muganho wesilicon carbide sintered pane zvakajairika kumanikidza
Muchidimbu, ceramics inogadzirwa nekupisa yekutsikirira sintering process ine zvirinani kuita, asi mutengo wekugadzira unowedzerawo zvakanyanya; Ceramics yakagadzirirwa nekudzvanyirirwa sintering ine yakakwirira mbishi zvinhu zvinodiwa, yakakwirira sintering tembiricha, hombe chigadzirwa saizi shanduko, yakaoma maitiro uye yakaderera kuita; Zvigadzirwa zveceramic zvinogadzirwa nekuita sintering maitiro zvine hunyoro hwakanyanya, yakanaka anti-ballistic performance, uye yakaderera mutengo wekugadzirira. Yakasiyana-siyana sintering gadziriro yesilicon carbide ceramics ine zvayakanakira nezvayakaipira, uye mamiriro ekushandisa achave akasiyana. Ndiyo mutemo wakanakisisa wekusarudza nzira yekugadzirira yakakodzera maererano nechigadzirwa uye kuwana kuenzana pakati pemutengo wakaderera uye kushanda kwepamusoro.
Nguva yekutumira: Oct-29-2024