ʻO ke kola Kanthal AF 837 resistohm alchrome Y fecral alloy

He mea hoʻohuihui hao-chromium-aluminium ferritic ʻo Kanthal AF (FeCrAl alloy) no ka hoʻohana ʻana i nā mahana a hiki i 1300°C (2370°F). Hōʻike ʻia ka mea hoʻohuihui e ke kūpaʻa oxidation maikaʻi loa a me ke kūpaʻa ʻano maikaʻi loa e hopena ana i ke ola lōʻihi o nā mea.

Hoʻohana pinepine ʻia ʻo Kan-thal AF i nā mea hoʻomehana uila i loko o nā umu ʻoihana a me nā mīkini home.

ʻO kahi laʻana o nā noi ma ka ʻoihana mīkini hana aia i nā mea mica hāmama no nā toasters, nā mea hoʻomaloʻo lauoho, i nā mea ʻano meander no nā mea hoʻomehana peʻahi a ma ke ʻano he mau mea coil hāmama ma luna o ka mea hoʻokaʻawale fiber i loko o nā mea hoʻomehana aniani seramika ma nā ʻano, i nā mea hoʻomehana seramika no nā pā paila, nā coil ma luna o ka fiber seramika i hoʻoheheʻe ʻia no nā pā kuke me nā kapuahi seramika, i nā mea coil kau ʻia no nā mea hoʻomehana peʻahi, i nā mea uea pololei kau ʻia no nā radiators, nā mea hoʻomehana convection, i nā mea porcupine no nā pū ea wela, nā radiators, nā mea hoʻomaloʻo tumble.

ʻŌlelo Pōkole Ma ke aʻo ʻana i kēia manawa, ua wehewehe ʻia ke ʻano hana pala o ka hui FeCrAl kalepa (Kanthal AF) i ka wā o ka annealing i loko o ke kinoea nitrogen (4.6) ma 900 °C a me 1200 °C. Ua hana ʻia nā hoʻāʻo Isothermal a me thermo-cyclic me nā manawa hōʻike like ʻole, nā helu hoʻomehana, a me nā mahana annealing. Ua hana ʻia ka hoʻāʻo oxidation i ka ea a me ke kinoea nitrogen e ka nānā ʻana o ka thermogravimetric. Hōʻike ʻia ka microstructure e ka microscopy electron scanning (SEM-EDX), Auger electron spectroscopy (AES), a me ka nānā ʻana o ka beam ion i kālele ʻia (FIB-EDX). Hōʻike nā hopena e hana ʻia ka holomua o ka pala ma o ka hoʻokumu ʻana o nā wahi nitridation subsurface kūloko, i haku ʻia me nā ʻāpana pae AlN, kahi e hōʻemi ai i ka hana alumini a hoʻoulu i ka embrittlement a me ka spallation. ʻO nā kaʻina hana o ka hoʻokumu ʻana o Al-nitride a me ka ulu ʻana o ka unahi Al-oxide e pili ana i ka mahana annealing a me ka helu hoʻomehana. Ua ʻike ʻia ʻo ka nitridation o ka FeCrAl alloy he hana wikiwiki ia ma mua o ka oxidation i ka wā annealing i loko o kahi kinoea nitrogen me ke kaomi hapa oxygen haʻahaʻa a ke hōʻike nei i ke kumu nui o ka hōʻino ʻana o ka alloy.

Hoʻolauna Ua kaulana nā mea hoʻohuihui FeCrAl (Kanthal AF ®) no ko lākou kūpaʻa oxidation kiʻekiʻe i nā mahana kiʻekiʻe. Pili kēia waiwai maikaʻi loa i ka hoʻokumu ʻia ʻana o ka unahi alumina thermodynamically stabil ma luna o ka ʻili, kahi e pale ai i ka mea mai ka oxidation hou aʻe [1]. ʻOiai nā waiwai kūpaʻa corrosion kiʻekiʻe, hiki ke kaupalena ʻia ke ola o nā ʻāpana i hana ʻia mai nā mea hoʻohuihui FeCrAl inā hōʻike pinepine ʻia nā ʻāpana i ka thermal cycling ma nā mahana kiʻekiʻe [2]. ʻO kekahi o nā kumu no kēia, ʻo ia ka mea hoʻokumu unahi, alumini, i hoʻopau ʻia i loko o ka matrix alloy ma ka ʻāpana subsurface ma muli o ka haki ʻana o ka thermo-shock a me ka hoʻoponopono hou ʻana o ka unahi alumina. Inā emi ka nui o ka alumini i koe ma lalo o ka noʻonoʻo koʻikoʻi, ʻaʻole hiki i ka alloy ke hoʻoponopono hou i ka unahi pale, e hopena ana i ka oxidation breakaway catastrophic ma ka hoʻokumu ʻana o nā oxides hao e ulu wikiwiki ana a me nā oxides chromium [3,4]. Ma muli o ka lewa a puni a me ka permeability o nā oxides surface hiki i kēia ke hoʻomaʻamaʻa i ka oxidation kūloko a i ʻole nitridation a me ka hoʻokumu ʻana o nā pae i makemake ʻole ʻia ma ka ʻāpana subsurface [5]. Ua hōʻike ʻo Han lāua ʻo Young i loko o ka unahi alumina e hana ana i nā hui Ni Cr Al, kahi ʻano paʻakikī o ka oxidation kūloko a me ka nitridation e hoʻomohala ʻia [6,7] i ka wā o ke kaʻapuni wela ma nā mahana kiʻekiʻe i loko o ka lewa ea, ʻoi aku hoʻi i nā hui e loaʻa ana nā mea hana nitride ikaika e like me Al a me Ti [4]. ʻIke ʻia nā unahi oxide Chromium he nitrogen permeable, a hana ʻo Cr2 N ma ke ʻano he papa sub-scale a i ʻole he precipitate kūloko [8,9]. Hiki ke manaʻo ʻia kēia hopena e ʻoi aku ka koʻikoʻi ma lalo o nā kūlana kaʻapuni wela e alakaʻi ai i ka haki ʻana o ka unahi oxide a me ka hōʻemi ʻana i kona pono ma ke ʻano he pale i ka nitrogen [6]. No laila, hoʻomalu ʻia ke ʻano corrosion e ka hoʻokūkū ma waena o ka oxidation, kahi e alakaʻi ai i ka hoʻokumu ʻana/mālama ʻana o ka alumina pale, a me ka nitrogen ingress e alakaʻi ana i ka nitridation kūloko o ka matrix alloy ma ka hoʻokumu ʻana o ka pae AlN [6,10], kahi e alakaʻi ai i ka spallation o kēlā ʻāpana ma muli o ka hoʻonui ʻana o ka thermal o ka pae AlN i hoʻohālikelike ʻia me ka matrix alloy [9]. I ka wā e hōʻike ai i nā mea hoʻohuihui FeCrAl i nā mahana kiʻekiʻe i nā lewa me ka oxygen a i ʻole nā ​​mea hāʻawi oxygen ʻē aʻe e like me H2O a i ʻole CO2, ʻo ka oxidation ka hopena koʻikoʻi, a hoʻokumu ʻia ka unahi alumina, kahi mea impermeable i ka oxygen a i ʻole nitrogen i nā mahana kiʻekiʻe a hāʻawi i ka pale ʻana i ko lākou komo ʻana i loko o ka matrix alloy. Akā, inā hōʻike ʻia i ka lewa hoʻemi (N2 + H2), a me ka māwae unahi alumina pale, hoʻomaka kahi oxidation breakaway kūloko ma ka hoʻokumu ʻana o nā oxides Cr a me Ferich pale ʻole, e hāʻawi ana i kahi ala kūpono no ka hoʻolaha ʻana o ka nitrogen i loko o ka matrix ferritic a me ka hoʻokumu ʻana o ka pae AlN [9]. Hoʻopili pinepine ʻia ka lewa nitrogen pale (4.6) i ka noi ʻoihana o nā mea hoʻohuihui FeCrAl. No ka laʻana, ʻo nā mea hoʻomehana kū'ē i loko o nā umu mālama wela me ka lewa nitrogen pale he laʻana o ka hoʻohana ākea o nā mea hoʻohuihui FeCrAl i loko o ia ʻano. Hōʻike nā mea kākau ua lohi loa ka wikiwiki o ka oxidation o nā mea hoʻohuihui FeCrAlY i ka wā e annealing ai i loko o kahi lewa me nā kaomi hapa haʻahaʻa oxygen [11]. ʻO ka pahuhopu o ke aʻo ʻana, ʻo ia ke hoʻoholo inā paha e pili ana ka annealing i loko o ke kinoea (99.996%) nitrogen (4.6) (Messer® spec. impurity level O2 + H2O < 10 ppm) i ke kūpaʻa ʻana i ka pala o ka FeCrAl alloy (Kanthal AF) a me ka nui o kona hilinaʻi ʻana i ka mahana annealing, kona ʻano (thermal-cycling), a me ka wikiwiki o ka hoʻomehana ʻana.