ʻO Boron Carbide Ceramics: Hoʻolauna i ka ʻImi ʻepekema, Waiwai, a me nā noi kipi o kahi mea ʻoi loa ka paʻakikī
1. Hoʻomaka i ka Boron Carbide: He Mea ma na Kiekie
Boron carbide (B ₄ C) ke kū nei ʻo ia kekahi o nā huahana artificial maikaʻi loa i ʻike ʻia i nā huahana o kēia wā noiʻi ʻepekema, hoʻokaʻawale ʻia e kona kau ʻana i waena o nā mea paʻakikī loa ma ka Honua, ʻoi aku ma mua o ke daimana a me cubic boron nitride.
(ʻO Boron Carbide Ceramic)
Hoʻokumu mua ʻia i ke kenekulia 19, Ua ulu maoli ka boron carbide mai kahi ʻimi noiʻi hale hana i mea pono i nā ʻōnaehana hoʻolālā kiʻekiʻe., nā mea hou palekana, a me nā noi nuklea.
ʻO kāna hui kūikawā o ka paʻa loa, hoemi emi, kiʻekiʻe neutron absorption cross-section, a he mea koʻikoʻi ka paʻa kemika kūikawā i nā kaiapuni kahi e hāʻule ai nā mea maʻamau.
Hāʻawi kēia ʻatikala i kahi mākaʻikaʻi ākea akā hiki ke loaʻa i nā seramika boron carbide, luʻu ʻana i loko o kona ʻano ʻātoma, ʻenehana synthesis, hale noho a hale kalepa paha, a me ke ʻano o nā noi holomua e hoʻohana i kāna mau hiʻohiʻona kupaianaha.
ʻO ka pahuhopu ka hoʻopaʻa ʻana i ka hakahaka ma waena o ka ʻike lapaʻau a me ka hoʻohana pono, hāʻawi i ka poʻe heluhelu i kahi hohonu, i hoʻonohonoho pono ʻia i ke ʻano o ka hana ʻana o kēia mea seramika kupaianaha i ka ʻenehana hou.
2. Hoʻokumu Atomic a me ke Kemika Kumu
2.1 Nā ʻano Lattice Crystal a me nā ʻano hoʻopaʻa
ʻO Boron carbide crystallize i loko o kahi ʻano rhombohedral (hui wahi R3m) me kahi kelepona paʻakikī e hoʻokomo i kahi stoichiometry loli, mai B ₄ C a i B ₁₀. ELIMA C.
ʻO ke kumu kumu o kēia hale he 12-atom icosahedra i haku nui ʻia me nā ʻātoma boron., hoʻopili ʻia e nā kaulahao pololei ʻekolu-atoma e hoʻolōʻihi i ka latticework kristal.
ʻO ka icosahedra he mau puʻupuʻu paʻa loa ma muli o ka hoʻopaʻa ʻana o ka covalent ikaika i loko o ka pūnaewele boron., ʻoiai nā kaulahao inter-icosahedral– loaʻa nā hoʻonohonoho C-B-C a i ʻole B-B-B– he kuleana koʻikoʻi i ka hoʻokumu ʻana i nā ʻano hale noho mechanical a me nā kikohoʻe.
Ke alakaʻi nei kēia ʻano kūikawā i kahi huahana me kahi kiʻekiʻe o ka hoʻopili covalent (pau 90%), ʻo ia ka mea e mālama pono ana i kona kūpaʻa phenomenal a me ka paʻa wela.
ʻO ka ʻike ʻana o ke kalapona ma nā pae kaulahao e hoʻonui i ka paʻa o ka hale, akā naʻe, hiki i nā ʻokoʻa mai ka stoichiometry maikaʻi ke hoʻopuka i nā hemahema e pili ana i ka pono mechanical a me ka sinterability.
(ʻO Boron Carbide Ceramic)
2.2 ʻAʻole i maʻamau ka haku mele ʻana a me ke kemika hala
ʻAʻole like me kekahi mau seramika me ka mālama ʻana i ka stoichiometry, Hōʻike ka boron carbide i kahi ʻano like like ʻole, e ʻae ana i ka hoʻololi nui ʻana i ka ratio boron-to-carbon me ka ʻole o ke keakea ʻana i ka ʻāpana aniani holoʻokoʻa.
Hiki i kēia hoʻololi ke hiki i nā waiwai kūpono no nā noi kikoʻī, ʻoiai ke hōʻike nei ia i nā paʻakikī i ka hoʻoponopono ʻana a me ka hoʻohālikelike pono.
Nā hemahema e like me ka nele o ke kalapona, nā puka boron, a he mea maʻamau ka distortions icosahedral a hiki ke hoʻopili i ka paʻakikī, māwae ʻoʻoleʻa, a me ka conductivity uila.
ʻo kahi laʻana, make-up under-stoichiometric (waiwai borona) ʻoi aku ka ʻoi aku o ka paʻakikī akā e hōʻemi ʻia ka paʻakikī o ka haki, ʻoiai ʻo nā ʻano like ʻole o ka carbon-waiwai e hōʻike i ka hoʻomaikaʻi ʻana i ka sinterability i ka lilo o ka paʻakikī.
ʻO ka hoʻomaopopo ʻana a me ka hoʻoponopono ʻana i kēia mau hemahema he mea koʻikoʻi i ka noiʻi boron carbide holomua, kūikawā no ka hoʻonui ʻana i ka pono i ka pale a me nā noi nuklea.
3. Nā ʻenehana Synthesis a me ka Hana Hana
3.1 Nā Hana Hana Nui
Hana ʻia ka pauka Boron carbide ma o ka hoʻohaʻahaʻa carbothermal kiʻekiʻe, he kaʻina hana i loaʻa ai ka waika boric (H ₃ BO EKOLU) aiʻole boron oxide (B ELUA O ₃) pane ʻia me nā kumuwaiwai kalapona e like me ka aila coke a i ʻole ka lanahu i loko o ka umu uila.
Ke hoʻomau nei ka pane e like me ka hoʻokō:
B ELUA O ₃ + 7C → 2B ʻEHA C + 6CO (kinoea)
Hana ʻia kēia kaʻina hana i nā pae wela ma mua 2000 ° C, e kāhea ana i ka hoʻokomo ikehu nui.
ʻO ka hopena B ʻEhā C ma hope o ka wili ʻia a hoʻomaʻemaʻe ʻia no ka hoʻopau ʻana i ke kalapona hou a me nā oxide i hoʻokō ʻole ʻia..
ʻO nā ʻenehana ʻē aʻe e pili ana i ka hoʻemi magnesiothermic, ka hoʻopili ʻana i ka laser-kōkua, a me ka synthesis arc plasma, e hāʻawi i ka mana ʻoi aku ka maikaʻi ma luna o ka nui o ka ʻāpana a me ka maʻemaʻe akā ua kaupalena ʻia i ka hana liʻiliʻi a kikoʻī paha.
3.2 Paʻakikī i ka Densification a me ka Sintering
Ma waena o kekahi o nā paʻakikī koʻikoʻi loa i ka hana ʻana o ka boron carbide ceramic e loaʻa ana i ka densification piha ma muli o kāna paʻa covalent paʻa a me ka hoʻohaʻahaʻa ʻana i ka coefficient self-diffusion..
ʻO ka hoʻopaʻa ʻana maʻamau me ka ʻole o ka hoʻopaʻa ʻana i nā pae porosity ma luna 10%, hoʻopilikia nui i ka ikaika mechanical a me ka hana ballistic.
No ka lanakila ʻana i kēia, hoʻohana ʻia nā ʻenehana hoʻopaʻapaʻa holomua:
Puhi Wela (HP): Hoʻopili i ka hoʻohana like ʻana o ka mehana (maʻa mau 2000– 2200 ° C )a me ke kaomi uniaxial (20– 50 MPa) i loko o kahi ʻano inert, hana ana i ka mānoanoa kokoke-theoretical.
Pumi Isostatic Pumehana (HIP): Hoʻohana i ka wela kiʻekiʻe a me ke koʻikoʻi kinoea isotropic (100– 200 MPa), ka wehe ʻana i nā pores i loko a me ka hoʻonui ʻana i ke kūpaʻa mechanical.
Spark Plasma Sintering (SPS): Hoʻohana pololei i ka pulsed e hoʻomehana wikiwiki i ka pauda compact, hiki i ka hoʻopaʻa ʻana i nā pae wela haʻahaʻa a me nā manawa pōkole loa, ka mālama ʻana i ke ʻano o ka palaoa.
Nā mea hoʻohui e like me ke kalapona, silika, Hōʻike pinepine ʻia nā pahu metala hoʻololi e paipai i ka hoʻopuehu ʻana o ka palena palaoa a hoʻoikaika i ka sinterability, ʻoiai e hoʻoponopono pono ʻia lākou e pale aku i ka paʻa paʻa.
4. Noho Mechanical a me ke Kino
4.1 Paʻa kūʻokoʻa a me ka pale ʻana i ka lole
Kaulana ʻo Boron carbide no kona paʻakikī Vickers, ʻokoʻa maʻamau mai 30 i 35 Awelika helu papa, hoʻonoho iā ia i waena o nā mea paʻakikī loa i ʻike ʻia.
Hoʻololi kēia paʻa paʻa i ke kūpaʻa maikaʻi i ka lole abrasive, hana maikaʻi ʻo B FOUR C no nā noi e like me nā nozzles sandblasting, e hoemi ana i na mea paahana, a hoʻohana i nā pā i ka ʻeli ʻana a me nā mea hana ʻoluʻolu.
ʻO ka mea ʻaʻahu i loko o ka boron carbide e pili ana i ka microfracture a me ka huki ʻana i waho e kūʻē i ka deformation plastic, he ano o na porcelains palupalu.
Eia naʻe, kona paa paa haahaa (maʻamau 2.5– 3.5 MPa · m 1ST / ʻELUA) hiki ke hoʻopau i ka hoʻolaha ma lalo o ka hoʻouka ʻana, e koi ana i ka hoʻolālā akahele ma nā noi ikaika.
4.2 Haʻahaʻa haʻahaʻa a me nā kikoʻī kiʻekiʻe ikaika
Me ka mānoanoa o pili 2.52 g/cm EKOLU, ʻO ka boron carbide kekahi o nā porcelains hale māmā loa i loaʻa, ka hoʻohana ʻana i kahi pōmaikaʻi nui i nā noi paona.
ʻO kēia haʻahaʻa haʻahaʻa, hoʻohui pū ʻia me ka ʻoi loa o ka compressive (pau 4 GPa), alakaʻi i ka ikaika kikoʻī phenomenal (ka hoʻohālikelike ikaika-i-density), mea koʻikoʻi no ka aerospace a me nā ʻōnaehana pale kahi e pono ai ka emi ʻana o ka nuipaʻa.
ʻo kahi laʻana, ma ka pale kino a me ke kaʻa, Hāʻawi ʻo B FOUR C i ka palekana premium i kēlā me kēia kaumaha i hoʻohālikelike ʻia me ke kila a i ʻole alumina, ka ʻae ʻana i ka māmā, ʻoi aku ka nui o nā ʻōnaehana palekana kelepona.
4.3 ʻO ke kūpaʻa wela a me ke kemika
Hōʻike ka Boron carbide i ke kūpaʻa wela, ka malama ana i kona mau home mechanical e like me 1000 ° C i nā kaiapuni inert.
He wahi hehee kiekie kona a puni 2450 ° C a me kahi helu hoʻonui wela hoʻemi (~ 5.6 × 10 ⁻⁶/ K), hoʻohui ʻia i ka pale ʻana i ka haʻalulu wela.
Ma kemika, ua pale loa ia i ka waika (koe naʻe nā ʻakika oxidizing e like me HNO ₃) a me nā metala wai, kūpono ia no ka hoʻohana ʻana i nā lewa kemika koʻikoʻi a me nā mea kanu mana atomika.
Eia naʻe, ʻoi aku ka nui o ka oxidation 500 ° C i ka ea, hana ana i ka boric oxide a me carbon dioxide, ka mea hiki ke wawahi i ka pono o ka ili i ka manawa.
Pono pinepine ʻia nā papa pale a i ʻole ka mālama ʻana i ke kaiapuni i nā pilikia oxidizing kiʻekiʻe.
5. Nā noi huna a me ka hopena ʻenehana
5.1 Palekana Ballistic a me ka pale pale
ʻO Boron carbide kahi mea pōhaku kihi i ka pale māmā o kēia wā ma muli o kona hui like ʻole o ka paʻa a me ka mānoanoa hoʻemi..
Hoʻohana nui ʻia i ka in:
Nā pā seramika no ka pale kino (Pale III a me IV).
Pale kaʻa no ka pūʻali koa a me nā noi mākaʻi.
ʻO ka pale mokulele a me ka helicopter cockpit.
I nā ʻōnaehana pale hui, Kākoʻo mau ʻia nā tile B ₄ C e nā polymers i hoʻoikaika ʻia i ka fiber (e.g., Kevlar a i ʻole UHMWPE) e hoʻopau i ke koena o ka ikehu kinetic ma hope o ka haki ʻana o ka papa seramika i ka projectile.
Me ka nānā ʻole i kona paʻa kiʻekiʻe, Hiki iā B ʻEhā C ke hana “amorphization” ma lalo o ka hopena kiʻekiʻe, kahi hanana e kaupalena ana i kāna hana me nā pilikia ikaika loa, hoʻoikaika i ka hoʻopaʻa ʻana i nā hoʻololi hoʻohuihui a me nā porcelain hybrid.
5.2 Hoʻolālā Nukelea a me ka hoʻohana ʻana i ka neutron
Ma waena o nā hana koʻikoʻi o ka boron carbide e noho mau ana i ka mana reactor nuklea a me nā ʻōnaehana palekana a palekana..
Ma muli o ke kiʻekiʻe o ka neutron absorption cross-section o ka ¹⁰ B isotope (3837 hale papaa no nā neutron wela), Hoʻohana ʻia ʻo B ʻEhā C ma:
Nā lāʻau hoʻomalu no nā reactors wai kaomi (PWRs) a me ka paila wai reactors (Nā BWR).
Nā ʻāpana pale Neutron.
Pūnaehana pani pani pilikia.
ʻO kona hiki ke komo i nā neutrons me ka ʻole o ka pehu nui a i ʻole ka luku ʻia ma lalo o ka irradiation e lilo ia i huahana punahele i nā kaiapuni nuklea..
Eia naʻe, hana ʻea helium mai ka ¹⁰ B(n, a)⁷ Hiki i ka hopena Li ke hoʻoulu i ke kaomi o loko a me ka microcracking me ka manawa, pono i ka hoʻolālā akahele a me ka nānā ʻana i nā noi lōʻihi.
5.3 Nā mea ʻenehana a me nā mea pale lole
Ma waho aʻe o ka pale a me nā mākeke nuklea, Loaʻa ka boron carbide i ka hoʻohana piha ʻana i nā noi ʻoihana e kāhea ana i ke kūpaʻa ʻoi loa:
Nozzles no ka ʻoki ʻana i ka wai wai a me ke one.
ʻO nā lining no nā pamu a me nā pani pani e lawelawe ana i nā slurries ʻinoʻino.
Hoʻemi i nā mea hana no nā huahana non-ferrous.
ʻO kona ʻano kemika a me ka paʻa wela e hiki ai ke hoʻokō me ka hilinaʻi i loko o nā lewa hoʻoheheʻe kemika ʻino kahi e pau koke ai nā mea kila..
6. Nā Kūlana o ka wā e hiki mai ana a me ka noiʻi noiʻi mua
ʻO ka wā e hiki mai ana o nā porcelains boron carbide e pili ana i ka lanakila ʻana i kāna mau mea paʻa– ʻoi aku ka paʻa haʻahaʻa haʻahaʻa a me ka pale ʻana i ka oxidation– me ke ano o ka haku mele a me ka nanostructuring.
Aia nā kuhikuhi noiʻi noiʻi i kēia manawa:
Ka ulu ʻana o B ₄ C-SiC, B ₄ C-TiB ₂, a me B EHA C-CNT (carbon nanotube) nā pūhui e hoʻoikaika i ka ikaika a me ka conductivity thermal.
ʻO ka hoʻololi ʻana i ka ʻili a me ka hoʻopau ʻana i nā mea hou e hoʻoikaika i ka pale ʻana i ka oxidation.
Hana hoʻohui (3D paʻi ʻana) o nā ʻāpana B ʻEhā C me ka hoʻohana ʻana i nā hoʻolālā binder jetting a me SPS.
Ke hoʻomau nei ka ʻimi noiʻi ʻepekema i mea e ulu ai, Hoʻonohonoho ʻia ka boron carbide e pāʻani i kahi hana ʻoi aku ka maikaʻi i nā hana hou o ka hanauna e hiki mai ana, mai nā ʻāpana lorry hypersonic i nā mea hoʻouluulu nuklea hou.
E hoʻopau, ʻO nā seramika boron carbide ke kū nei i kahi kiʻekiʻe o ka pono o nā mea i hana ʻia, ka hoʻohui ʻana i ka paʻa paʻa, emi mānoanoa, a me nā waiwai noho nuklea kūikawā i loko o ka mea hoʻokahi.
Ma o ka holomua mau i ka synthesis, lawelawe ana, a me ka noi, ke hoʻomau nei kēia mea kupanaha i nā palena o ka mea hiki i ka hoʻolālā hana kiʻekiʻe.
Mea hoolaha
ʻO Advanced Ceramics i hoʻokumu ʻia ma ʻOkakopa 17, 2012, he ʻoihana ʻenehana kiʻekiʻe i hoʻopaʻa ʻia i ka noiʻi a me ka hoʻomohala ʻana, hana ʻana, hana ʻana, kūʻai a me nā lawelawe ʻenehana o nā mea pili a me nā huahana. Loaʻa kā mākou huahana akā ʻaʻole i kaupalena ʻia i nā Boron Carbide Ceramic Products, ʻO Boron Nitride Ceramic Products, Nā Huahana Seramika Silicon Carbide, ʻO nā huahana seramika Silicon Nitride, Zirconium Dioxide Ceramic Products, etc. Inā hoihoi ʻoe, e ʻoluʻolu e hoʻokaʻaʻike mai iā mākou.([email protected])
Nā huaʻōlelo: Boron Carbide, ʻO Boron Ceramic, ʻO Boron Carbide Ceramic
ʻO nā ʻatikala a me nā kiʻi a pau mai ka Pūnaewele. Inā loaʻa kekahi pilikia kope, e ʻoluʻolu e kelepona mai iā mākou i ka manawa e holoi ai.
E nīnau iā mākou