Sil\u012bcija karb\u012bds, ko bie\u017e\u0101k d\u0113v\u0113 par karborundu jeb SiC, ir \u0101rk\u0101rt\u012bgi ciets (9 balles p\u0113c Mosa skalas) materi\u0101ls ar lielisk\u0101m termiskaj\u0101m \u012bpa\u0161\u012bb\u0101m, ko ieg\u016bst, elektriskaj\u0101 kr\u0101sn\u012b kars\u0113jot augstas kvalit\u0101tes sil\u012bcija smiltis ar smalki samaltu ogli.<\/p>\n
Var\u0161 ir daudzpus\u012bgi izmantojams r\u016bpniec\u012bb\u0101 un ikdien\u0101, piem\u0113ram, abraz\u012bvajam smil\u0161pap\u012bram un sl\u012bp\u0113\u0161anas diskiem, griez\u0113jinstrumentiem, cietiem keramikas materi\u0101liem un griez\u0113jinstrumentiem. Turkl\u0101t tas var iztur\u0113t \u013coti augstas temperat\u016bras, nek\u013c\u016bstot viegli uzliesmojo\u0161s, kas ir svar\u012bga \u012bpa\u0161\u012bba.<\/p>\n
Sil\u012bcija karb\u012bda fizik\u0101l\u0101s \u012bpa\u0161\u012bbas ir ciet\u012bba, stingr\u012bba un siltumvad\u012btsp\u0113ja. Tas var iztur\u0113t temperat\u016bru l\u012bdz 1600 gr\u0101diem p\u0113c Celsija, vienlaikus saglab\u0101jot apstr\u0101des sp\u0113ju p\u0113c intens\u012bva sa\u0137epin\u0101\u0161anas un sl\u012bp\u0113\u0161anas procesa. Sil\u012bcija karb\u012bds ir otrais \u0101rk\u0101rt\u012bgi cietais materi\u0101ls uz Zemes, un p\u0113c t\u0101diem d\u0101rgiem procesiem k\u0101 sa\u0137epin\u0101\u0161ana un sl\u012bp\u0113\u0161ana to var prec\u012bzi apstr\u0101d\u0101t ar prec\u012bz\u0101m pielaid\u0113m.<\/p>\n
Moisan\u012bts dab\u0101 sastopams k\u0101 \u0101rk\u0101rt\u012bgi rets miner\u0101ls, un to masveid\u0101 ra\u017eo pulvera un krist\u0101lu veid\u0101, lai izmantotu abraz\u012bvos materi\u0101los, keramikas pl\u0101ksn\u0113s bru\u0146uvest\u0113m, automobi\u013cu bremz\u0113s un saj\u016bgos, pusvad\u012bt\u0101ju ier\u012bc\u0113s un d\u0101rgakme\u0146os.<\/p>\n
SiC kristaliz\u0113jas da\u017e\u0101d\u0101s strukt\u016br\u0101s ar at\u0161\u0137ir\u012bgu sil\u012bcija un oglek\u013ca atomu sak\u0101rtojumu, no kur\u0101m visizplat\u012bt\u0101k\u0101 ir dimanta kubisk\u0101 f\u0101ze (b-SiC), kas ir \u013coti stabila l\u012bdz\u012bgu atomu radiusu d\u0113\u013c un nodro\u0161ina lielisku siltumvad\u012btsp\u0113ju. SiC ne\u0161\u0137\u012bst \u016bden\u012b, bet \u0161\u0137\u012bst izkaus\u0113tos s\u0101rmos un dzelz\u012b. K\u0101 krist\u0101liska viela t\u0101 kr\u0101sa ir no za\u013cas l\u012bdz zilgani melnai.<\/p>\n
Sil\u012bcija karb\u012bds (SiC) ir \u0101rk\u0101rt\u012bgi iztur\u012bgs materi\u0101ls - \u0137\u012bmiski inerts, termiski stabils un pla\u0161i izmantojams da\u017e\u0101d\u0101s jom\u0101s, s\u0101kot no abraz\u012bvu, siltuma vad\u012bbas sist\u0113mu un modernas elektronikas ra\u017eo\u0161anas l\u012bdz pat met\u0101lu sakaus\u0113jumu stipr\u012bbas palielin\u0101\u0161anai. K\u0101 v\u0113rt\u012bga metalur\u0123iska piedeva tas samazina ugunsiztur\u012bbas zudumus, vienlaikus iev\u0113rojami uzlabojot met\u0101lu sakaus\u0113jumu stipr\u012bbu.<\/p>\n
SiC var atrast dab\u0101 k\u0101 miner\u0101lu moisan\u012btu meteor\u012btos, bet bie\u017e\u0101k to sintez\u0113, izmantojot A\u010dsona procesu, kas kop\u0161 19. gadsimta beig\u0101m ir nosaukts t\u0101 izgudrot\u0101ja Edvarda Goodri\u010da A\u010dsona v\u0101rd\u0101. Tas ietver t\u012bra sil\u012bcija dioks\u012bda (sil\u012bcija dioks\u012bda) un smalki samalta oglek\u013ca mais\u012bjuma kars\u0113\u0161anu elektrisk\u0101 kr\u0101sn\u012b l\u012bdz temperat\u016brai 1700-2500 gr\u0101dos p\u0113c Celsija.<\/p>\n
SiC eksist\u0113 k\u0101 vair\u0101ki polimorfi, kas at\u0161\u0137iras atkar\u012bb\u0101 no t\u0101, k\u0101 tiek sakrauti sil\u012bcija un oglek\u013ca atomi, un komerci\u0101los apst\u0101k\u013cos visbie\u017e\u0101k sastopams alfa sil\u012bcija karb\u012bds (a-SiC), kam rakstur\u012bga se\u0161st\u016braina krist\u0101lisk\u0101 strukt\u016bra, l\u012bdz\u012bga virtc\u012btam. Beta modifik\u0101cijas ar uz seju centr\u0113tu kubisku krist\u0101lisko strukt\u016bru, piem\u0113ram, cinka blende vai sfeller\u012bts, l\u012bdz nesenam laikam tika reti izmantotas, bet to liel\u0101kas virsmas laukuma d\u0113\u013c t\u0101s aizvien bie\u017e\u0101k izmanto k\u0101 heterog\u0113no katalizatoru nes\u0113jus.<\/p>\n
Sil\u012bcija karb\u012bds var lepoties ar izcilu \u012bpatn\u0113jo siltuma v\u0113rt\u012bbu un siltumvad\u012btsp\u0113ju, kas ir tr\u012bs reizes augst\u0101ka nek\u0101 vara, ar maz\u0101ku termisko izple\u0161anos nek\u0101 met\u0101liem vai keramikas materi\u0101liem, padarot to par lielisku materi\u0101lu izv\u0113li lietojumiem, kas saist\u012bti ar ekstr\u0113m\u0101m temperat\u016br\u0101m vai vibr\u0101cij\u0101m.<\/p>\n
Savienojums, ko ieg\u016bst, sil\u012bcija smiltis (SiO2) un koksu kars\u0113jot elektriskaj\u0101 kr\u0101sn\u012b \u013coti augst\u0101 temperat\u016br\u0101, veidojot dzeltenza\u013cus l\u012bdz zilganza\u013cus l\u012bdz zilgani melnus p\u0101rsteidzo\u0161us krist\u0101lus ar dzelteniem l\u012bdz za\u013ciem l\u012bdz za\u013ciem to\u0146iem un kop\u0113jo dzeltenza\u013cu-zilganza\u013cu-meln\u012bgi melnu nokr\u0101su atkar\u012bb\u0101 no temperat\u016bras iestat\u012bjumiem. R\u016bpnieciskie produkti var satur\u0113t dzelzs piemais\u012bjumus, kas Fe2O3 kl\u0101tb\u016btnes d\u0113\u013c izraisa br\u016bnu vai melnu kr\u0101sojumu.<\/p>\n
T\u012brs sil\u012bcija karb\u012bds darbojas k\u0101 elektriskais izolators, bet t\u0101 pla\u0161\u0101s joslas spraugas pusvad\u012bt\u0101ju \u012bpa\u0161\u012bbas padara to piem\u0113rotu energoelektronikas lietojumiem. Lai pan\u0101ktu met\u0101lisko vad\u012btsp\u0113ju, var pievienot sl\u0101pekli vai fosforu, savuk\u0101rt beriliju, boru, alum\u012bniju vai galliju var pievienot, lai palielin\u0101tu darba spriegumu - ide\u0101li piem\u0113rots t\u0101diem lietojumiem k\u0101 elektrisko transportl\u012bdzek\u013cu invertori.<\/p>\n
Sil\u012bcija karb\u012bds sp\u0113j iztur\u0113t \u013coti augstas temperat\u016bras, padarot to par lielisku materi\u0101lu ugunsiztur\u012bgo oder\u0113jumu un keramikas materi\u0101lu izgatavo\u0161anai. Turkl\u0101t no sil\u012bcija karb\u012bda var izgatavot ar\u012b abraz\u012bvus materi\u0101lus, piem\u0113ram, smil\u0161pap\u012bru, griez\u0113jinstrumentus un sl\u012bpripas, ko izmanto augsta spiediena\/augstas temperat\u016bras lietojumos, piem\u0113ram, automobi\u013cu deta\u013c\u0101s un ra\u0137e\u0161u sprausl\u0101s.<\/p>\n
Izkaus\u0113tas s\u0101ls ciet\u012bbas r\u0101d\u012bt\u0101js p\u0113c Mosa skalas ir 9, t\u0101p\u0113c t\u0101 ir iztur\u012bgs materi\u0101ls. Turkl\u0101t t\u0101 \u0137\u012bmisk\u0101 inertums noz\u012bm\u0113, ka to nemaina sk\u0101bes, s\u0101rmi vai citi \u0161\u0137\u012bdumi, piem\u0113ram, sk\u0101bes. Turkl\u0101t temperat\u016bras l\u012bdz 2700 gr\u0101diem p\u0113c C nek\u0101di neapdraud un nemaina t\u0101 \u012bpa\u0161\u012bbas.<\/p>\n
Sil\u012bcija karb\u012bda pulveri var kombin\u0113t ar neoksid\u0113tu saistvielu, veidojot pastu, ko p\u0113c tam var sabl\u012bv\u0113t un veidot, izmantojot auksto izostatisko pres\u0113\u0161anu vai ekstr\u016bziju. Bie\u017ei tiek izv\u0113l\u0113ts m\u0101ls, jo tas nov\u0113r\u0161 SiO2 iztvaiko\u0161anu kakli\u0146u apgabalos starp da\u013ci\u0146\u0101m, vienlaikus veicinot bl\u012bv\u0113\u0161anu, t\u0101d\u0113j\u0101di padarot \u0161o metodi gan ekonomisku, gan efekt\u012bvu bl\u012bvu sil\u012bcija karb\u012bda izstr\u0101d\u0101jumu ra\u017eo\u0161an\u0101.<\/p>","protected":false},"excerpt":{"rendered":"
Silicon carbide, more commonly referred to as Carborundum or SiC, is an extremely hard (9 on Mohs scale) material with excellent thermal properties that is created by heating high-grade silica sand with finely ground carbon in an electric furnace. Copper has multiple applications in industry and everyday life, such as abrasive sandpaper and grinding wheels, …<\/p>\n