Ka hoʻopaʻa ʻana
ʻO ka sintering panesilika carbide keramikaʻO ke kaʻina hana e pili ana i ka hoʻopili ʻana i ka ceramic, sintering flux infiltration agent compacting, reaction sintering ceramic product preparation, silicon carbide wood ceramic preparation a me nā ʻanuʻu ʻē aʻe.
ʻO ka hoʻoheheʻe ʻana i ka nozzle silicon carbide
ʻO ka mua, 80-90% o ka pauka seramika (i haku ʻia me hoʻokahi a ʻelua paha pauka oka pauda kalapona silikaa me ka pauka boron carbide), 3-15% o ka pauka kumu kalapona (i haku ʻia i hoʻokahi a ʻelua paha o ke kalapona ʻeleʻele a me ka resin phenolic) a me 5-15% o ka mea hoʻoheheʻe ʻia (phenolic resin, polyethylene glycol, hydroxymethyl cellulose a i ʻole paraffin) i hui like ʻia. e hoʻohana ana i ka wili poepoe e loaʻa ai ka pauka i hui ʻia, i hoʻomaloʻo ʻia a hoʻomaloʻo ʻia, a laila kaomi ʻia i loko o kahi ʻōpala no ka loaʻa ʻana o kahi paʻi ceramic me nā ʻano kikoʻī like ʻole.
ʻO ka lua, 60-80% silika pauka, 3-10% silicon carbide pauka a me 37-10% boron nitride pauka i hui like ʻia, a paʻi ʻia i loko o kahi mold e kiʻi i kahi sintering flux infiltration agent compact.
Hoʻopili pū ʻia ka pāpaʻi ceramic a me ka infiltrant compact sintered, a hoʻokiʻekiʻe ʻia ka mahana i 1450-1750 ℃ i loko o ka umu ahi me kahi degere ʻole ma lalo o 5 × 10-1 Pa no ka sintering a me ka mālama wela no 1-3 mau hola e loaʻa ai kahi hopena sintered ceramic huahana. Hoʻopau ʻia ke koena infiltrant ma luna o ka ʻili o ka ceramic sintered ma ke kaomi ʻana e kiʻi i kahi pepa seramika paʻa, a mālama ʻia ke ʻano kumu o ka compact.
ʻO ka hope loa, ua apono ʻia ke kaʻina hana sintering, ʻo ia hoʻi, ka wai silikona a i ʻole nā mea hoʻoheheʻe ʻia me ka hana ʻana i ke kiʻekiʻe wela infiltrates i loko o ka porous ceramic blank i loaʻa i ke kalapona ma lalo o ka hana o ka ikaika capillary, a hoʻopili me ke kalapona i loko e hana i ka carbide silicon, ka mea. e hoʻonui i ka leo, a hoʻopiha ʻia nā pores i koe me ka silika elemental. Hiki ke kalapona maʻemaʻe a i ʻole silika carbide/carbon-based composite material. Loaʻa ka mea mua ma ka catalytically curing a me ka pyrolyzing i kahi resin organik, kahi pore mua a me kahi mea hoʻoheheʻe. Loaʻa ka mea hope ma ka pyrolyzing silicon carbide particles/resin-based composite material e kiʻi ai i ka silicon carbide/carbon-based composite material, a i ʻole ma ka hoʻohana ʻana i ka α-SiC a me ka pauka kalapona e like me nā mea hoʻomaka a me ka hoʻohana ʻana i kahi kaʻina hana kaomi a injection paha e loaʻa ai ka composite. mea waiwai.
ʻO ka hoʻopaʻa paʻa ʻole
Hiki ke hoʻokaʻawale ʻia ke kaʻina hana hoʻoheheʻe ʻole o ka silicon carbide i loko o ka sintering solid-phase a me ka wai-phase sintering. I nā makahiki i hala iho nei, ʻo ka noiʻi masilika carbide seramikama ka home a me nā ʻāina ʻē i kālele nui ʻia i ka sintering wai-phase. ʻO ke kaʻina hana hoʻomākaukau seramika: hui ʻia nā mea wili pōleʻa–> hoʻoheheʻe granulation–> kaomi maloʻo–> paʻa kino ʻōmaʻomaʻo–> hoʻoheheʻe ʻia.
ʻO nā huahana carbide silika i hoʻopaʻa ʻole ʻia
Hoʻohui i nā ʻāpana 96-99 o ka pauka ultrafine silicon carbide (50-500nm), 1-2 ʻāpana o ka pauka boron carbide ultrafine (50-500nm), 0.2-1 ʻāpana o ka nano-titanium boride (30-80nm), 10-20 ʻāpana o ka wai-soluble phenolic resin, a me 0.1-0.5 mau hapa o ke kiʻekiʻe-efficiency dispersant i ka poepoe. wili no ka wili poepoe a hui pu no 24 mau hora, a hookomo i ka slurry i huiia i loko o ka pahu hui no ka hooulu ana no 2 hora e wehe i na ohu i loko o ka slurry.
Hoʻopili ʻia ka hui ʻana i luna i loko o ka hale kiaʻi granulation, a ʻo ka pauka granulation me ka morphology particle maikaʻi, ka wai maikaʻi, ka laulā haʻahaʻa haʻahaʻa a me ka wai maʻemaʻe e loaʻa ma ka kāohi ʻana i ke kaomi ʻana, ka wela inlet ea, ka wela o ka ea a me ka nui o ka nui. ʻO ka hoʻololi ʻana o ka centrifugal frequency he 26-32, ʻo ka mahana inlet ea he 250-280 ℃, ʻo ka ea puka makani he 100-120 ℃, a ʻo ke kaomi inlet slurry he 40-60.
Hoʻokomo ʻia ka pauka granulation i luna i loko o kahi mold carbide cemented no ke kaomi ʻana e loaʻa kahi kino ʻōmaʻomaʻo. ʻO ke ʻano kaomi ʻana he bidirectional pressure, a ʻo ka mīkini paʻi kaomi ʻana he 150-200 tons.
Hoʻokomo ʻia ke kino ʻōmaʻomaʻo i paʻi ʻia i loko o kahi umu maloʻo no ka hoʻomaloʻo ʻana a me ka hoʻōla ʻana no ka loaʻa ʻana o ke kino ʻōmaʻomaʻo me ka ikaika o ke kino ʻōmaʻomaʻo maikaʻi.
Hoʻokomo ʻia ke kino ʻōmaʻomaʻo i hoʻōla ʻia ma luna aʻegraphite cruciblea hoʻonohonoho pono a maʻemaʻe, a laila hoʻokomo ʻia ka graphite crucible me ke kino ʻōmaʻomaʻo i loko o kahi umu hoʻoheheʻe kiʻekiʻe kiʻekiʻe no ke kī ʻana. ʻO ka mahana ahi ka 2200-2250 ℃, a ʻo ka manawa insulation he 1-2 mau hola. ʻO ka mea hope loa, loaʻa nā seramika carbide silika kiʻekiʻe.
Sintering pae paʻa
Hiki ke hoʻokaʻawale ʻia ke kaʻina hana hoʻoheheʻe ʻole o ka silicon carbide i loko o ka sintering solid-phase a me ka wai-phase sintering. Pono ka hoʻohui ʻana i nā mea hoʻohui sintering, e like me Y2O3 binary a me nā mea hoʻohui ternary, e hana ai i ka SiC a me kāna mau mea hoʻohuihui e hōʻike i ka wai-phase sintering a loaʻa ka densification ma kahi haʻahaʻa haʻahaʻa. ʻO ke ʻano o ka hoʻomākaukau ʻana i nā ceramics silicon carbide paʻa paʻa i hoʻohui ʻia i ka hui ʻana o nā mea maka, ka hoʻoulu ʻana i ka granulation, ka hoʻoheheʻe ʻana, a me ka sintering vacuum. ʻO ke kaʻina hana kūikawā penei:
ʻO 70-90% o ka submicron α silicon carbide (200-500nm), 0.1-5% o ka boron carbide, 4-20% o ka resin, a me 5-20% o ka mea hoʻopili organik i hoʻokomo ʻia i loko o kahi hui hui a hoʻohui ʻia me ka wai maʻemaʻe no ka pulu. huikau. Ma hope o 6-48 mau hola, hele ʻia ka slurry i hui ʻia ma kahi sieve 60-120 mesh;
Hoʻopili ʻia ka sieved slurry ma o ka hale kiaʻi spray granulation. ʻO ka wela inlet o ka hale kiaʻi granulation spray he 180-260 ℃, a ʻo ka mahana o waho he 60-120 ℃; ʻo ka nui o ka nui o ka mea granulated he 0.85-0.92g / cm3, ʻo 8-11s / 30g ka fluidity; ua kānana ʻia ka mea granulated ma kahi kānana 60-120 mesh no ka hoʻohana hope ʻana;
E koho i ka mold e like me ka makemake o ka huahana, e hoʻouka i ka mea granulated i loko o ka mold cavity, a hana i ka hoʻoheheʻe ʻana i ka lumi wela ma ke kaomi o 50-200MPa e loaʻa ai kahi kino ʻōmaʻomaʻo; a i ʻole e kau i ke kino ʻōmaʻomaʻo ma hope o ka hoʻoheheʻe ʻia ʻana i loko o kahi mea kaomi isostatic, e hana i ke kaomi isostatic ma ke kaomi o 200-300MPa, a loaʻa kahi kino ʻōmaʻomaʻo ma hope o ke kaomi lua;
E hoʻokomo i ke kino ʻōmaʻomaʻo i hoʻomākaukau ʻia ma nā ʻanuʻu ma luna aʻe i loko o kahi umu hoʻoheheʻe ʻia no ka sintering, a ʻo ka mea kūpono ʻo ia ka silicon carbide bulletproof ceramic; i ke kaʻina hana hoʻoheheʻe ma luna, e hoʻokuʻu mua i ka umu hoʻoheheʻe, a i ka wā i hiki ai ke degere o ka vacuum i ka 3-5 × 10-2 Ma hope o Pa, ua hele ke kinoea inert i loko o ka umu sintering i ke kaomi maʻamau a laila wela. ʻO ka pilina ma waena o ka mahana wela a me ka manawa: ka lumi wela i 800 ℃, 5-8 mau hola, mālama wela no 0.5-1 hola, mai 800 ℃ a 2000-2300 ℃, 6-9 mau hola, mālama wela no 1 a 2 mau hola, a laila hoʻomaloʻo me ka umu ahi a hāʻule i kahi mahana wela.
Hoʻopili ʻia ka microstructure a me ka palena palaoa o ka carbide silika ma ke kaomi maʻamau
I ka pōkole, ʻoi aku ka maikaʻi o ka hana ʻana o nā ceramics i hana ʻia e ke kaʻina hana sintering wela, akā hoʻonui nui ʻia ke kumukūʻai hana; ʻO nā ceramics i hoʻomākaukau ʻia e ka pressureless sintering ʻoi aku ka kiʻekiʻe o nā koi maka, ke kiʻekiʻe o ka sintering wela, nā loli nui o ka huahana, ka hana paʻakikī a me ka hana haʻahaʻa; ʻO nā huahana keramika i hana ʻia e ke kaʻina hana sintering he kiʻekiʻe kiʻekiʻe, hana anti-ballistic maikaʻi, a me ke kumukūʻai hoʻomākaukau haʻahaʻa. ʻO nā kaʻina hana hoʻomākaukau sintering o ka silicon carbide ceramics i ko lākou pono ponoʻī a me nā hemahema, a ʻokoʻa hoʻi nā hiʻohiʻona noi. ʻO ia ke kulekele maikaʻi loa e koho i ke ʻano hoʻomākaukau kūpono e like me ka huahana a loaʻa i kahi kaulike ma waena o ke kumukūʻai haʻahaʻa a me ka hana kiʻekiʻe.
Ka manawa hoʻouna: Oct-29-2024