Txoj kev rau cov hlau. Hom alloys. Kev npaj ntawm alkali hlau

Niaj hnub nimno tus txiv neej nyob rau hauv nws lub neej niaj hnub no yog surrounded los ntawm ib tug ntau yam ntawm hlau. Feem ntau cov khoom uas peb siv, cov tshuaj yog tam sim no. Nws tag nrho cov tshwm sim vim hais tias cov neeg tau pom ntau txoj kev los mus tsim hlau.

Yuav ua li cas yog ib tug hlau

Cov nqi tshuaj rau cov neeg koom nyob rau hauv inorganic Science News for KIDS. Muab co tso cai ib tug neeg los mus tsim ib tug ntau zoo meej cov txheej txheem, ua rau peb lub neej. Yuav ua li cas lawv sawv cev rau? Ua ntej peb xav txog cov kev ntawm cov hlau, nws yog tsim nyog los nkag siab txog dab tsi. Co yog ib pab pawg neeg ntawm cov tshuaj hais nyob rau hauv daim ntawv ntawm tej yam yooj yim tshuaj muaj yam ntxwv zog:

• thermal thiab hluav taws xob conductivity;

• siab ductility;

• ci.

Ib tug txiv neej yuav tau yooj yim qhov txawv lawv los ntawm lwm yam. Ib tug yam ntxwv feature ntawm tag nrho cov co yog cov xub ntiag ntawm ib tug tshwj xeeb ci. Nws los ntawm cov rog xav txog ntawm lub teeb rays ntog rau ntawm qhov chaw tsis nco lawv. Gloss - yog tus khoom teejtug uas yog tag nrho cov co, tab sis nws yog feem ntau kom meej meej manifested nyob rau hauv cov nyiaj.

Niaj hnub no, zaum sab 96 ntawm cov tshuaj hais, tab sis yog tsis yog txhua txhua ntawm lawv yog paub los ntawm hauj science. Lawv muab faib ua tej pawg nyob rau hauv lawv lub xam qhovkev yam ntxwv zog. Yog li co yog cov nram qab no:

• alkaline - 6;

• alkaline - 6;

• hloov - 38;

• Hnav - 11;

• semimetals - 7;

• lanthanides - 14;

• actinides - 14.

muab co

Nyob rau hauv kev txiav txim mus fabricate lub alloy yuav tsum xub tau txais lub hlau los ntawm tej yam ntuj tso ore. Neeg ntsiab - cov no yog cov tshuaj uas muaj nyob rau hauv qhov nyob rau hauv lub dawb lub xeev. Cov no muaj xws platinum, kub, tin thiab mercury. Lawv sib cais los ntawm impurities mechanically los yog los ntawm cov tshuaj reagents.

Qhov seem co yog muab rho tawm los ntawm kev kho mob nrog lub tebchaw. Lawv muaj nyob rau hauv ntau yam minerals. Ore - qhov no minerals thiab cov pob zeb, uas muaj hlau tebchaw li oxides, carbonates, los yog sulfides. Rau lawv cov khoom siv tshuaj kho mob.

Txoj kev tau txais co:

• rov qab los ntawm cov pa roj carbon oxides;

• tin ntawm tin txais pob zeb;

• zus tau tej cov cam khwb cia hlau los ntawm hlau ore ;

• burning ntawm cov leej faj tebchaw nyob rau hauv tshwj xeeb furnaces.

Yuav kom pab txhawb tau co ntawm ore pob zeb no ntxiv rau lawv ntau yam tshuaj hu ua fluxes. Lawv pab tshem pliaj impurities xws li av nplaum, limestone, xuab zeb. Raws li ib tug tshwm sim ntawm txoj kev no ua fusible tebchaw hu ua slag.

Nyob rau hauv lub xub ntiag ntawm tseem ceeb cov nqi ntawm cov impurities ua ntej hlau ore smelting enriched los ntawm qhov kev tshem tawm ntawm ib tug loj feem ntawm ruaj Cheebtsam. Cov feem ntau lug siv txoj kev rau qhov kev kho no - flotation, magnetic thiab gravitational txoj kev.

alkali hlau

Pawg tau txais alkali hlau - ib tug complex txheej txheem. Qhov no yog vim lub fact tias lawv muaj nyob rau hauv cov xwm tsuas nyob rau hauv daim ntawv ntawm cov tshuaj lub tebchaw. Txij li thaum lawv txo cov neeg ua hauj, lawv npaj nrog siab cov nqi zog. Muaj ob peb txoj kev ntawm tau alkali hlau:

• Li yuav tsum npaj kom txhij los ntawm nws cov oxide nyob rau hauv vacuo los yog los ntawm yaj electrolysis nws chloride tsim thaum lub sij hawm ua spodumene.

• Sodium rho los ntawm ci nrog thee tshauv nyob rau hauv kaw crucibles los yog chloride electrolysis ntawm lub qhuav nrog tas li ntawd ntawm calcium. Tus thawj txoj kev yog lub feem ntau lub sij hawm-siv.

• Potassium tau qhuav electrolysis los yog nws cov ntsev, sodium vapor dua los ntawm nws cov chloride. Tsis tas li ntawd nws yog tsim los ntawm reacting ib tug molten poov tshuaj hydroxide thiab kua sodium ntawm ib tug kub ntawm 440 ° C.

• cesium thiab rubidium rho los es lawv calcium chloride ntawm 700-800 ° C los yog zirconium ntawm 650 ° C. Kev npaj ntawm cov alkali hlau nyob rau hauv no txoj kev yog heev zog intensive thiab kim.

Sib txawv ntawm cov hlau thiab alloys

Nyob rau hauv hauv paus ntsiab lus, ib tug ntshiab ciam ntawm hlau thiab lawv cov alloys zoo uas tsis yog-existent, txij li thaum txawm lub feem ntau ntshiab, yooj yim tshuaj yog ib feem ntawm impurities. Yog li ntawd dab tsi yog qhov txawv ntawm lawv? Yuav luag tag nrho cov co siv nyob rau hauv kev lag luam thiab nyob rau hauv lwm yam ceg ntawm kev khwv nyiaj txiag, yog siv nyob rau hauv daim ntawv ntawm cov alloys tau los ntawm kev ntxiv tej hom phiaj rau lub ntsiab tshuaj caij lwm yam.

alloys

Technology xav tau ib tug ntau yam ntawm cov hlau cov ntaub ntawv. Nyob rau hauv cov ntaub ntawv no, ntshiab tshuaj ntsiab yog tsis suab siv vim lawv tsis muaj qhov tsim nyog zog rau cov neeg. Rau lawv xav tau kev pab peb muaj invented ntau txoj kev rau cov alloys. Qhov no lub sij hawm yog hais txog ib tug macroscopically homogenous khoom, uas muaj ob los yog ntau tshaj tshuaj ntsiab. Wherein lub nws yog xim hlau Cheebtsam yog predominant nyob rau hauv lub hlau. Qhov no tshuaj nws muaj nws tus kheej qauv. Nyob rau hauv alloys paub qhov txawv cov nram qab no Cheebtsam:

• lub hauv paus, muaj raws ntawm ib tug los yog ntau tshaj co;

• me me ntxiv ntawm modifying thiab alloying ntsiab;

• undeleted impurities (txheej txheem, tej yam ntuj tso, random).

Uas hlau alloys yog lub ntsiab yam ntxwv khoom. Nyob rau hauv technology, muaj ntau tshaj li 5,000.

hom ntawm alloys

Dua li no ntau yam ntawm alloys, feem ntau cov neeg ua si tus nqi rau cov neeg uas yog raws li nyob rau hauv hlau thiab txhuas. Nws yog lawv uas yog feem ntau pom muaj nyob rau hauv lub neej txhua hnub. Hom alloys yog cov sib txawv. Ntxiv mus, lawv muab faib raws li ob peb kev. Txij li thaum muaj ntau txoj kev rau cov alloys. Raws li qhov no txog kev paub, lawv muab faib ua:

• alloy, uas yog tau ua los ntawm crystallization ntawm lub qhuav zoo Cheebtsam.

• Hmoov, los ntawm kev siv lub compression ntawm sib tov ntawm hmoov thiab tom ntej sintering thaum muaj kev kub kub. Thiab feem ntau yam ntawm tej alloys yog tsis tsuas yooj yim tshuaj hais, tab sis lawv ntau yam tebchaw xws li carbides ntawm titanium los yog tungsten alloys nyob rau hauv cov khoom. Ntxiv lawv nyob rau hauv txawv ntau hloov thaj chaw ntawm nws yog xim hlau cov ntaub ntawv.

Txoj kev rau qhov kev npaj ntawm alloys nyob rau hauv daim ntawv ntawm ib tug tiav lawm tsab xov xwm los yog lub workpiece yog sib cais rau hauv:

• casting (silumin, cam khwb cia hlau);

• deformable (hlau);

• hmoov (titanium tungsten).

hom alloys

Txoj kev rau cov co yog sib txawv, thiab yog li manufactured tshuav rau lawv cov ntaub ntawv muaj ntau zog. Nyob rau hauv lub khoom hauv lub xeev alloys yog:

• homogenous (uniform), muaj raws ntawm muaju ntawm tib hom. Lawv feem ntau xa mus rau raws li ib-theem.

• ua kev (heterogeneous), xa mus rau raws li multi-theem. Thaum lawv tau txais nyob rau hauv lub hauv paus ntawm lub alloy yog muab raws li ib tug khoom tov (matrix theem). Muaj pes tsawg leeg ua kev tshuaj ntawm no hom nyob rau nyob tus yeees ntawm nws cov tshuaj hais. Tej alloys yuav muaj xws li cov nram qab no Cheebtsam: interstitial thiab substitutional khoom dlaws, tshuaj tebchaw (carbides, intermetallic tebchaw, nitrides), crystallites ntawm tej yam yooj yim tshuaj.

alloy zog

Tsis hais dab tsi txoj kev ua hlau thiab alloys siv, lawv lub zog yog kiag li txiav txim los ntawm tus siv lead ua qauv ntawm cov theem thiab microstructure ntawm cov ntaub ntawv. Txhua yam ntawm lawv yog cov sib txawv. Lub macroscopic thaj chaw ntawm alloys nyob ntawm seb lawv microstructure. Lawv yog cov nyob rau hauv txhua rooj plaub txawv los ntawm lawv cov theem yam ntxwv nyob thiaj tau tuaj rau tus siv lead ua qauv ntawm cov khoom. Macroscopic homogeneity ntawm heterogeneous (multiphase) alloys tau los ntawm teeb tis ntawm theem nyob rau hauv lub hlau matrix.

Qhov tseem ceeb tshaj thaj chaw ntawm lub alloy yog pom tias yuav weldability. Txwv tsis pub, lawv yeej zoo tib yam hlau. Yog li, lub alloys muaj thermal thiab hluav taws xob conductivity, ductility thiab reflectivity (gloss).

ntau ntau yam alloys

Ntau txoj kev rau cov alloys tau tso cai ib tug neeg mus npaj ib tug loj tus naj npawb ntawm nws yog xim hlau ntaub ntawv muaj ntau zog thiab cov yam ntxwv. Raws li lub hom phiaj lawv muab faib mus rau hauv lub nram qab no pab pawg:

• Lub Khoos Loos Tsev (steel, duralumin, hlau). Qhov no pab pawg neeg no muaj xws li, alloys nrog tshwj xeeb. Yog li ntawd lawv txawv intrinsically zoo los yog anti-kev sib txhuam zog. Cov no muaj xws dag thiab bronze.

• Yuav kom sau cov bearings (babbitt).

• Rau hluav taws xob cua sov thiab ntsuas cov cuab yeej siv (nichrome, manganin).

• Rau qhov ntau lawm ntawm tej cuab yeej (yeej).

Nyob rau hauv zus tau tej cov neeg siv lwm yam nws yog xim hlau ntaub ntawv xws li tsawg-melting, Thaum tshav kub kub-resistant, corrosion-resistant thiab amorphous alloys. Tsis tas li ntawd yog siv lug hlau nplaum thiab thermoelectrics (teluridy selenide thiab Bismuth, hmoov txhuas, antimony thiab lwm tus).

ferroalloy

Yuav luag tag nrho cov ntawm smelted hlau nyob rau hauv lub ntiaj teb no yog raws kev coj kom lub zus tau tej cov yooj yooj yim thiab hlau steels. Nws kuj yog siv nyob rau hauv qhuav ntawm npua hlau. hlau alloys tau nws tej chaw vim lub fact uas muaj pab zog rau tib neeg. Lawv twb tau los ntawm kev ntxiv mus rau lub yooj yim tshuaj caij ntawm lub ntau yam. Yog li, txawm lub fact tias ntau yam hlau alloys manufactured nyob rau hauv lub hauv paus ntawm ib tug yeeb tshuaj, steels thiab cam khwb cia irons muaj ntau zog. Vim li no lawv yog cov sib txawv spheres ntawm daim ntawv thov. Feem ntau cov steels nyuaj tshaj hlau. Ntau txoj kev npaj cov co cia li yuav nrhiav tau ntau qib (qib) ntawm cov hlau alloys.

Paub thaj chaw ntawm lub alloys

Los ntawm alloying co thiab ib co lwm yam hais yuav tau ntaub ntawv nrog paub yam ntxwv. Piv txwv li, tus tawm lub dag lub zog ntawm ntshiab txhuas yog 35 MPa. Nyob rau hauv qhov kev npaj ntawm cov hlau hlau nrog tooj liab (1.6%), ZN (5.6%), magnesium (2.5%) lub Performance index tshaj 500 MPa.

Vim compound ntau yam ratios sib txawv ntawm cov tshuaj yuav tsum tau nws yog xim hlau ntaub ntawv nrog paub magnetic, thermal los yog hluav taws xob zog. Lub ntsiab lub luag hauj lwm nyob rau hauv tus txheej txheem no yog lub alloy qauv sawv cev ib tug muab faib rau nws cov muaju thiab hom bonds ntawm cov atoms.

Steel thiab hlau

Cov alloys yog ua los ntawm sib txuas ntawm hlau thiab carbon (2%). Nyob rau hauv zus tau tej cov alloyed ntaub ntawv ntxiv rau lawv ib tug npib tsib xee, chromium, vanadium. Tag nrho ntawm lub niaj zaus hom steel yog muab faib mus rau hauv:

• cov uas tsis muaj (0.25% carbon) siv rau qhov siv thiab ua ntau yam Siv;

• siab carbon (ntau tshaj 0,55%) yog npaj rau zus tau tej cov txiav cov cuab yeej.

Ntau hom ntawm alloy steels yog siv nyob rau hauv mechanical engineering, thiab lwm yam khoom.

ib tug hlau hlau carbon, uas yog qhov feem pua ntawm 2-4% yog hu ua npua hlau. Muaj pes tsawg leeg ntawm no cov ntaub ntawv uas muaj xws li silicon. Ntawm ntau yam cam khwb cia hlau cov khoom muaj zoo txhua yam khoom.

Tsis-ferrous co

Nyob rau hauv tas li ntawd mus hlau, thiab lwm yam hais siv tau los ua ib tug ntau yam ntawm cov hlau cov ntaub ntawv. Raws li ib tug tshwm sim ntawm lawv lub tebchaw no tsis yog-ferrous alloys. Nyob rau hauv lub neej, cov neeg tau pom tus loj tshaj cov ntaub ntawv thov rau lub hauv paus ntawm:

• Tooj, tooj dag hu ua. Lawv muaj 5-45% zinc. Yog hais tias cov ntsiab lus yog 5-20%, lub dag hu ua liab, thiab yog hais tias 20-36% - daj. Muaj tooj liab alloys nrog pob zeb ntais, tin, beryllium, txhuas. Lawv yog cov hu ua bronzes. Muaj ob peb hom ntawm cov alloys.

• Coj cov sawv cev ib pa solder (tretnik). Nyob rau hauv no alloy, mus rau 1 ib feem ntawm cov tshuaj pripadaet 2 qhov chaw tin. Nyob rau hauv zus tau tej cov bearings siv babbitt uas yog ib tug hlau lead, tin, arsenic thiab antimony.

• txhuas, titanium, magnesium thiab beryllium, uas yog sib tsis-ferrous alloys muaj siab zog thiab yav tom ntej txhua yam khoom.

Txoj kev rau cov kev npaj

Lub ntsiab txoj kev tau hlau thiab alloys:

• foundry uas tus solidification ntawm ib tug homogeneous sib tov ntawm txawv molten Cheebtsam. Rau alloys siv pyrometallurgical txoj kev nrhiav thiab electrometallurgical hlau. Tus thawj embodiment yog siv los ua cua sov nyoos thermal zog ua thaum lub sij hawm lub combustion txheej txheem. Tau los ntawm pyrometallurgical steel nyob rau hauv qhib-hearth furnaces thiab hlau nyob rau hauv lub moj tej tawg furnaces. Thaum electrometallurgical txheej txheem feedstock yog rhuab nyob rau hauv lub electric arc los yog induction furnaces. Nyob rau hauv cov ntaub ntawv no, lub raw khoom rasslavlyaetsya heev sai sai.

• Hmoov, nyob rau lub hmoov ntawm nws cov Cheebtsam siv rau cov ib alloy. Vim nias lawv muab ib tug tej yam zoo, thiab ces sintered nyob rau hauv tshwj xeeb furnaces.