Thaum tshav kub kub resistant alloy, tseem hu ua superalloy, yog qhov tseem ceeb heev rau kev lag luam department thiab daim ntawv thov technology teb nyob rau hauv kub kub.
Feem ntau hais lus, qhov siab dua qhov melting point ntawm cov ntaub ntawv hlau, qhov siab dua qhov ntsuas kub uas tuaj yeem siv tau. Qhov no yog vim qhov nce ntawm qhov kub thiab txias, cov khoom siv hluav taws xob ntawm cov khoom siv hlau txo qis, thiab cov qauv ntawm oxidation corrosion nce raws li. Yog li, cov ntaub ntawv hlau dav tsuas tuaj yeem ua haujlwm ntawm 500 degree ~ 600 degree rau lub sijhawm ntev. Cov hlau uas tuaj yeem ua haujlwm ntawm qhov kub siab tshaj 700 degree feem ntau hu ua cov hlau tsis muaj cua sov. "Heat resistance" txhais tau hais tias nws tuaj yeem tuav lub zog txaus thiab oxidation zoo nyob rau hauv qhov kub thiab txias.
Muaj ob txoj hauv kev los txhim kho oxidation tsis kam ntawm hlau: ib qho yog ntxiv Cr, Si, Al thiab lwm yam alloying ntsiab rau hauv cov hlau, los yog nqa tawm Cr, Si, Al alloying kev kho mob ntawm cov hlau. Lawv tuaj yeem ua cov yeeb yaj kiab xim ceev nrawm hauv cov pa oxidizing thiab khov kho rau saum hlau, yog li tiv thaiv oxidation los ntawm txuas ntxiv. Lwm qhov yog tsim cov ntsiab lus siab melting oxide, carbide, nitride thiab lwm yam kub resistant coatings ntawm cov hlau nto los ntawm ntau txoj kev.
Muaj ntau txoj hauv kev los txhim kho qhov kub thiab txias zog ntawm cov hlau. Los ntawm cov tshuaj lom neeg pom ntawm cov qauv thiab cov cuab yeej, muaj kwv yees li ob txoj hauv kev tseem ceeb:
Ib qho yog txhawm rau ua kom lub zog sib txuas ntawm cov atoms hauv cov hlau ntawm qhov kub thiab txias. Nws tau taw qhia tias lub zog ntawm daim ntawv cog lus hauv cov hlau feem ntau cuam tshuam nrog cov xov tooj ntawm cov hluav taws xob tsis sib xws hauv atoms. Los ntawm lub sij hawm lub sij hawm, cov hlau daim ntawv cog lus ntawm lub caij VI B yog lub zog tshaj nyob rau hauv tib lub sij hawm. Yog li, ntxiv Cr, Mo, W atoms rau hauv cov hlau muaj qhov zoo tshaj plaws.
Lwm qhov yog ntxiv cov ntsiab lus uas tuaj yeem tsim ntau yam carbides lossis intermetallic compounds kom ntxiv dag zog rau cov hlau matrix. Carbides generated los ntawm ib tug xov tooj ntawm kev hloov pauv hlau thiab carbon atoms mus rau interstitial tebchaw. Lawv ntxiv covalent daim ntawv cog lus nyob rau hauv lub hauv paus ntawm hlau bonds, yog li ntawd lawv muaj zoo hardness thiab siab melting point. Piv txwv li, ntxiv W, Mo, V, Nb tuaj yeem tsim WC, W2C, MoC, Mo2C, VC, NbC thiab lwm yam carbides, yog li ua kom lub zog kub ntawm cov hlau.
Ntxiv nrog rau cov hlau raws li kub-resistant alloys, npib tsib xee raws li, molybdenum raws li, niobium raws li thiab tungsten raws li kub-resistant alloys kuj tau npaj los ntawm txoj kev alloy. Lawv muaj cov khoom siv zoo thiab tshuaj lom neeg ruaj khov ntawm qhov kub thiab txias. Ntawm lawv, npib tsib xee puag alloy yog qhov zoo tshaj plaws super kub resistant hlau khoom, thiab cov matrix hauv cov qauv yog Ni? Cr? Cov khoom tov ntawm Co thiab Ni3Al hlau compound tuaj yeem siv tau ntawm 1000 degree ~ 1100 degree tom qab kho.
