Tus txiv neej niaj hnub yog ib puag ncig los ntawm ntau yam hlau hauv nws lub neej txhua hnub. Feem ntau ntawm cov khoom peb siv muaj cov tshuaj no. Qhov no tshwm sim vim tib neeg pom ntau txoj hauv kev kom tau txais hlau.
Dab tsi yog hlau
Inorganic chemistry cuam tshuam nrog cov khoom tseem ceeb no rau tib neeg. Tau txais cov hlau tso cai rau ib tus neeg los tsim cov cuab yeej zoo tshaj plaws uas txhim kho peb lub neej. Lawv yog dab tsi? Ua ntej xav txog cov txheej txheem dav dav kom tau txais cov hlau, nws yog qhov yuav tsum tau nkag siab tias lawv yog dab tsi. Cov hlau yog ib pab pawg ntawm cov tshuaj nyob rau hauv daim ntawv ntawm cov khoom yooj yim nrog cov yam ntxwv:
• thermal thiab hluav taws xob conductivity;
• siab ductility;
• glitter.
Ib tug neeg tuaj yeem paub qhov txawv ntawm lwm yam khoom. Ib tug yam ntxwv feature ntawm tag nrho cov hlau yog lub xub ntiag ntawm ib tug tshwj xeeb brilliance. Nws tau txais los ntawm kev cuam tshuam qhov teeb meem teeb pom kev zoo rau ntawm qhov chaw uas tsis xa lawv. Ci yog ib qho cuab yeej cuab tam ntawm tag nrho cov hlau, tab sis nws yog feem ntau hais nyob rau hauv silver.
NyobTxog rau tam sim no, cov kws tshawb fawb tau tshawb pom 96 cov tshuaj xws li tshuaj, txawm tias tsis yog txhua tus ntawm lawv tau lees paub los ntawm kev tshawb fawb. Lawv muab faib ua pawg nyob ntawm lawv cov yam ntxwv. Cov hlau hauv qab no raug cais raws li no:
• alkaline – 6;
• alkaline ntiaj teb – 6;
• kev hloov pauv – 38;
• teeb – 11;
• semimetals – 7;
• Lanthanides – 14;
• actinides – 14.
Tau txais cov hlau
Yuav ua kom cov hlau nplaum, koj yuav tsum xub tau txais hlau los ntawm ntuj ore. Native cov ntsiab lus yog cov khoom uas muaj nyob rau hauv cov xwm nyob rau hauv ib tug dawb lub xeev. Cov no muaj xws li platinum, kub, tin, mercury. Lawv raug cais los ntawm impurities mechanically lossis nrog kev pab ntawm cov tshuaj reagents.
Lwm cov hlau yog mined los ntawm kev ua lawv cov tebchaw. Lawv muaj nyob rau hauv ntau yam fossils. Ores yog cov ntxhia thiab pob zeb, uas suav nrog cov hlau sib txuas hauv daim ntawv oxides, carbonates lossis sulfides. Yuav kom tau txais lawv, kev ua tshuaj lom neeg yog siv.
Txoj kev kom tau txais cov hlau:
• txo cov oxides nrog thee;
• tau tin los ntawm pob zeb;
• hlau ore smelting;
• burning sulfur compounds hauv qhov cub tshwj xeeb.
Txhawm rau pab kom tshem tawm cov hlau los ntawm cov pob zeb ore, ntau yam tshuaj hu ua fluxes ntxiv rau lawv. Lawv pab tshem tawm pliaj impurities xws li av nplaum, limestone, xuab zeb. Raws li qhov tshwm sim ntawm cov txheej txheem no, fusible compounds tau txais,hu ua dross.
Nyob rau hauv lub xub ntiag ntawm ib tug tseem ceeb npaum li cas ntawm impurities, cov ore yog enriched ua ntej smelting cov hlau los ntawm tshem tawm ib tug loj ib feem ntawm cov khoom tsis tsim nyog. Txoj kev siv dav tshaj plaws rau kev kho mob no yog flotation, sib nqus thiab nqus.
Alkali hlau
Kev tsim cov hlau alkali ntau yog txheej txheem nyuaj dua. Qhov no yog vim lub fact tias lawv muaj nyob rau hauv cov xwm tsuas yog nyob rau hauv daim ntawv ntawm tshuaj compounds. Txij li thaum lawv txo cov neeg ua haujlwm, lawv cov khoom tsim tau nrog cov nqi zog siab. Muaj ntau txoj hauv kev los rho tawm cov hlau alkali:
• Lithium tuaj yeem tau txais los ntawm nws cov oxide hauv lub tshuab nqus tsev lossis los ntawm electrolysis ntawm yaj ntawm nws cov chloride, tsim thaum lub sij hawm ua cov spodumene.
• Sodium yog muab rho tawm los ntawm calcining soda nrog thee nyob rau hauv nruj kaw crucibles los yog los ntawm electrolysis ntawm ib tug chloride yaj nrog ntxiv ntawm calcium. Thawj txoj hauv kev yog siv sijhawm ntau tshaj.
• Potassium yog tau los ntawm electrolysis ntawm yaj ntawm nws cov ntsev los yog dhau sodium vapor los ntawm nws cov chloride. Nws kuj yog tsim los ntawm kev sib cuam tshuam ntawm molten potassium hydroxide thiab kua sodium ntawm qhov kub ntawm 440 ° C.
• Cesium thiab rubidium yog mined los ntawm kev txo lawv cov chlorides nrog calcium ntawm 700-800 ° C los yog zirconium ntawm 650 ° C. Tau txais alkali hlau nyob rau hauv txoj kev no yog lub zog siv zog thiab kim heev.
Qhov sib txawv ntawm cov hlau thiab alloys
Ib qhov tseeb ntawm ciam teb ntawm cov hlau thiab lawv cov alloys xyaum tsis muaj nyob, txij li txawm tias cov khoom ntshiab, yooj yim tshaj plaws muajqee qhov ntawm impurities. Yog li dab tsi yog qhov txawv ntawm lawv? Yuav luag tag nrho cov hlau siv nyob rau hauv kev lag luam thiab nyob rau hauv lwm yam sectors ntawm lub teb chaws kev khwv nyiaj txiag yog siv nyob rau hauv daim ntawv ntawm alloys tau lub hom phiaj los ntawm kev ntxiv lwm yam Cheebtsam rau lub ntsiab tshuaj.
Alloys
Technology xav tau ntau yam khoom siv hlau. Nyob rau tib lub sijhawm, cov ntsiab lus tshuaj ntshiab yog siv tsis tau, vim lawv tsis muaj cov khoom tsim nyog rau tib neeg. Rau peb cov kev xav tau, peb tau tsim ntau txoj hauv kev kom tau txais cov alloys. Lo lus no yog hais txog cov khoom siv macroscopically homogeneous uas muaj 2 los yog ntau yam tshuaj. Nyob rau hauv cov ntaub ntawv no, hlau Cheebtsam predominate nyob rau hauv lub alloy. Cov tshuaj no muaj nws tus kheej qauv. Hauv cov alloys, cov khoom hauv qab no yog qhov txawv:
• puag muaj ib lossis ntau dua hlau;
• me me ntxiv ntawm kev hloov kho thiab alloying ntsiab;
• non-removed impurities (technological, natural, random).
Hlau alloys yog cov khoom siv tseem ceeb. Hauv kev siv tshuab, muaj ntau dua 5000 ntawm lawv.
Nyob ntawm alloys
Txawm hais tias muaj ntau yam alloys, cov khoom raws li cov hlau thiab txhuas yog qhov tseem ceeb tshaj plaws rau tib neeg. Lawv yog cov feem ntau nyob rau hauv lub neej txhua hnub. Hom alloys txawv. Ntxiv mus, lawv tau muab faib ua ntau yam. Yog li ntau txoj kev ntawm kev tsim cov alloys yog siv. Raws li cov txheej txheem no, lawv muab faib ua:
• Cast, uastau los ntawm yaj crystallization ntawm cov khoom sib xyaw.
• hmoov, tsim los ntawm nias ib tug sib tov ntawm hmoov thiab ces sintering ntawm kub. Ntxiv mus, feem ntau cov khoom ntawm xws li alloys tsis yog tsuas yog cov tshuaj yooj yim, tab sis kuj muaj ntau yam sib txuas, xws li titanium lossis tungsten carbides hauv cov alloys nyuaj. Lawv qhov sib ntxiv hauv qee qhov kev hloov pauv cov khoom ntawm cov khoom siv hlau.
Txoj hauv kev kom tau txais cov alloys nyob rau hauv daim ntawv ntawm cov khoom tiav lossis qhov khoob tau muab faib ua:
• foundry (silumin, cam khwb cia hlau);
• wrought (steels);
• hmoov (titanium, tungsten).
Nyob ntawm alloys
Txoj kev kom tau txais cov hlau sib txawv, thaum cov ntaub ntawv ua tsaug rau lawv muaj cov khoom sib txawv. Nyob rau hauv lub xeev ntawm aggregation, alloys yog:
• Homogeneous (uniform), muaj cov muaju ntawm tib hom. Lawv feem ntau hu ua ib theem.
• Heterogeneous (heterogeneous), hu ua multiphase. Thaum lawv tau txais, ib qho kev daws teeb meem (matrix theem) yog coj los ua lub hauv paus ntawm cov hlau. Qhov muaj pes tsawg leeg ntawm cov tshuaj heterogeneous ntawm hom no nyob ntawm qhov muaj pes tsawg leeg ntawm nws cov tshuaj lom neeg. Cov hlau zoo li no yuav muaj cov khoom nram qab no: cov kev daws teeb meem ntawm interstitial thiab hloov pauv, cov tshuaj sib txuas (carbides, intermetallides, nitrides), crystallites ntawm cov khoom yooj yim.
Alloy khoom
Txawm hais tias txoj kev twg thiaj li tau txais cov hlau thiab alloys siv, lawv cov khoom raug txiav txim siab los ntawm crystalline.theem qauv thiab microstructure ntawm cov ntaub ntawv no. Txhua tus nyias txawv nyias. Cov khoom macroscopic ntawm alloys nyob ntawm lawv cov microstructure. Nyob rau hauv txhua rooj plaub, lawv txawv ntawm cov yam ntxwv ntawm lawv cov theem, uas yog nyob ntawm tus qauv siv lead ua ntawm cov khoom. Lub macroscopic homogeneity ntawm heterogeneous (multiphase) alloys yog tau los ntawm ib tug uniform faib ntawm theem nyob rau hauv cov hlau matrix.
Cov khoom tseem ceeb tshaj plaws ntawm cov hlau yog weldability. Txwv tsis pub, lawv zoo tib yam rau cov hlau. Yog li, alloys muaj thermal thiab hluav taws xob conductivity, ductility thiab reflectivity (luster).
Ntau yam alloys
Txoj kev sib txawv ntawm kev tau txais cov alloys tau tso cai rau tib neeg los tsim cov khoom siv hlau ntau nrog cov khoom sib txawv thiab cov yam ntxwv. Raws li lawv lub hom phiaj, lawv tau muab faib ua pawg hauv qab no:
• Cov qauv (steel, duralumin, cam khwb cia hlau). Cov pab pawg no kuj suav nrog cov alloys nrog cov khoom tshwj xeeb. Yog li ntawd, lawv txawv ntawm qhov kev nyab xeeb ntawm lub cev lossis kev sib txhuam cov khoom. Cov no suav nrog tooj dag thiab tooj.
• Rau cov kabmob (babbit).
• Rau cov khoom siv hluav taws xob cua sov thiab ntsuas (nichrome, manganin).
• Rau kev tsim cov cuab yeej txiav (yeej).
Hauv kev tsim khoom, tib neeg kuj siv lwm yam khoom siv hlau, xws li fusible, kub-resistant, corrosion-resistant thiab amorphous alloys. Magnets thiab thermoelectrics (telurides thiab selenides ntawm bismuth, lead, antimony thiab lwm yam) kuj tau siv dav.
hlau alloys
Xyaum txhua yam hlau smelted hauv ntiaj teb yog qhia rau kev tsim cov hlau yooj yim thiab alloyed. Nws kuj yog siv rau hauv kev tsim cov hlau. Hlau alloys tau txais lawv cov koob meej vim tias lawv muaj cov khoom muaj txiaj ntsig zoo rau tib neeg. Lawv tau txais los ntawm kev ntxiv ntau yam khoom siv rau cov tshuaj lom neeg yooj yim. Yog li, txawm tias muaj ntau yam hlau alloys yog tsim los ntawm ib yam khoom, steels thiab cam khwb cia hlau muaj cov khoom sib txawv. Yog li ntawd, lawv pom ntau yam kev siv. Cov hlau feem ntau nyuaj dua li cov hlau cam khwb cia. Ntau txoj hauv kev kom tau txais cov hlau no tso cai rau koj kom tau txais cov qib sib txawv (hom) ntawm cov hlau alloys.
Txhim kho cov khoom siv hlau
Los ntawm kev sib xyaw qee cov hlau thiab lwm yam tshuaj, cov khoom siv nrog cov yam ntxwv zoo tuaj yeem tau txais. Piv txwv li, lub zog tawm los ntawm ntshiab txhuas yog 35 MPa. Thaum tau txais ib qho hlau ntawm cov hlau no nrog tooj liab (1.6%), zinc (5.6%), magnesium (2.5%), daim duab no tshaj 500 MPa.
Los ntawm kev sib xyaw sib txawv ntawm cov tshuaj sib txawv, cov khoom siv hlau nrog cov khoom sib nqus, thermal lossis hluav taws xob zoo tuaj yeem tau txais. Lub luag haujlwm tseem ceeb hauv cov txheej txheem no yog ua los ntawm cov qauv ntawm cov hlau, uas yog kev faib tawm ntawm nws cov muaju thiab hom kev sib txuas ntawm atoms.
Hlau thiab hlau
Cov alloys no tau los ntawm kev sib xyaw hlau thiab carbon (2%). Hauv kev tsim cov khoom siv alloyed, lawv ntxivnickel, chrome, vanadium. Tag nrho cov hlau zoo tib yam tau muab faib ua hom:
• tsawg carbon (0.25% carbon) siv rau ntau yam qauv;
• Cov pa roj carbon ntau (ntau dua 0.55%) tsim los rau cov cuab yeej txiav.
Cov qib sib txawv ntawm cov hlau alloy yog siv hauv kev tsim kho tshuab thiab lwm yam khoom.
Cov hlau hlau nrog cov pa roj carbon, feem pua ntawm cov uas yog 2-4%, yog hu ua cam khwb cia hlau. Cov khoom no kuj muaj silicon. Ntau yam khoom uas muaj cov khoom siv zoo yog cam khwb cia hlau.
Non-ferrous hlau
Dhau li ntawm hlau, lwm yam tshuaj lom neeg kuj siv los ua ntau yam khoom siv hlau. Raws li qhov tshwm sim ntawm lawv kev sib xyaw ua ke, cov hlau tsis muaj hlau tau txais. Hauv tib neeg lub neej, cov ntaub ntawv raws li:tau pom qhov siv tau zoo tshaj plaws
• Tooj, hu ua tooj dag. Lawv muaj 5-45% zinc. Yog tias nws cov ntsiab lus yog 5-20%, ces tooj dag hu ua liab, thiab yog 20-36% - daj. Muaj cov alloys ntawm tooj liab nrog silicon, tin, beryllium, aluminium. Lawv hu ua bronzes. Muaj ob peb hom ntawm cov alloys.
• Lead, uas yog ib qho khoom siv (tretnik). Nyob rau hauv no alloy, 2 seem ntawm tin poob rau 1 feem ntawm cov tshuaj no. Bearings yog tsim los siv babbitt, uas yog ib qho hlau lead, tin, arsenic thiab antimony.
• Txhuas, titanium, magnesium thiab beryllium, uas yog lub teeb tsis-ferrous alloys nrog lub zog siab thiab zoo heev txhua yamkhoom.
Txoj kev tau txais
Txoj hauv kev tseem ceeb kom tau txais cov hlau thiab cov hlau:
• Foundry, nyob rau hauv uas ib tug homogeneous sib tov ntawm txawv molten Cheebtsam solidifies. Yuav kom tau txais cov alloys, pyrometallurgical thiab electrometallurgical txoj kev tau txais hlau yog siv. Hauv thawj qhov sib txawv, thermal zog tau txais hauv cov txheej txheem ntawm cov roj combustion yog siv los ua kom sov cov khoom siv raw. Txoj kev pyrometallurgical tsim cov hlau nyob rau hauv qhib-hearth furnaces thiab cam khwb cia hlau nyob rau hauv blast furnaces. Nrog rau txoj kev electrometallurgical, cov ntaub ntawv raw yog rhuab hauv induction lossis hluav taws xob arc rauv. Tib lub sijhawm, cov khoom siv raw yog softened sai heev.
• hmoov, uas cov hmoov ntawm nws cov khoom siv los ua cov hlau. Ua tsaug rau nias, lawv tau muab ib qho duab, thiab tom qab ntawd sintered hauv qhov cub tshwj xeeb.
