Hlau thiab alloys. Cov rooj ntom ntom rau cov hlau thiab alloys

2024 Tus sau: Angel Austin | [email protected]. Kawg hloov kho: 2024-01-02 17:48

Txhua tus menyuam kawm ntawv uas paub txog lub sijhawm teem sijhawm paub tias cov hlau nyob hauv nws ua rau feem ntau ntawm cov tshuaj. Ib qho ntawm cov yam ntxwv tseem ceeb ntawm lub cev rau lawv yog qhov ntom ntom. Xav txog tus nqi no hauv kab lus thiab muab lub rooj ntawm qhov ntom ntom ntawm cov hlau thiab alloys.

Dab tsi yog qhov ceev

Yog tias koj nqa tib lub ntim ntawm cov yas thiab hlau, ces thawj zaug yuav yooj yim dua qhov thib ob. Hloov pauv, ib daim yas yuav muaj qhov hnyav tib yam li ib daim hlau yog tias nws loj dua hauv ntim. Yog vim li cas rau qhov sib txawv no yog xws li lub cev muaj nuj nqis raws li qhov ceev. Cov mis rau xam nws yog raws li nram no:

ρ=m/V.

Ntawm no yog qhov loj ntawm lub cev, V yog nws ntim. Lo lus Greek tsab ntawv ρ (rho) feem ntau siv los qhia qhov ntom ntom. Nws ua raws los ntawm cov qauv uas cov units ntawm kev ntsuas hauv SI yog kilograms ib cubic meter (kg/m³). Cov chav uas tsis yog lub cev kuj tseem siv tau, xws li g/cm^{3 lossis g/l (rau cov kua).}

Dab tsi yog hlau

Ua ntej muab lub rooj ntawm qhov ntom ntom ntawm cov hlau, cia peb piav qhia yam khoom uas peb tham txog. Cov khoom siv hlau sib txawv ntawm cov hlau tsis yog hlau hauv siab thermal thiab hluav taws xob conductivity thiab ductility. Cov no yog lawv cov yam ntxwv tseem ceeb. Kuj tseem muaj cov khoom me me, xws li muaj cov yam ntxwv ntawm cov hlau nplaum, kev ua kom zoo, thiab qis electronegativity rau lawv cov atoms.

Tag nrho cov hlau nyob rau hauv ib txwm muaj nyob rau hauv daim ntawv. Qhov tsuas yog qhov tshwj xeeb yog mercury, uas qhov kub ntawm crystallization yog -39oC. Khoom hlau muaj nyob rau hauv daim ntawv ntawm ib tug siv lead ua lattice. Cov tom kawg yog ib qho kev sau ntawm atoms uas tau teeb tsa hauv qhov chaw hauv ib txoj hauv kev geometric. Txhua yam khoom siv dawb huv (ib qho khoom siv) hlau muaj nyob rau hauv ib qho ntawm peb hom siv lead ua lattices nyob rau hauv cov xwm txheej. Cov no yog cov kab hauv qab no:

• Face Centered Cubic (FCC).
• Lub Cev Cubic (BCC).
• Hexagonal kaw-packed (hcp).

Yog tias cov xwm txheej (kub, siab) hloov, ces cov hlau tuaj yeem mus ntawm ib qho mus rau lwm lub xeev crystalline. Ib qho piv txwv classic yog kev hloov pauv ntawm bcc hlau rau fcc thaum kub poob qis dua 1392^oC, lossis thaum nws nce siab dua 911^oC.

Metal density table

Qhov ntom ntawm cov hlau yog txiav txim siab los ntawm ob yam tseem ceeb:

• hom siv lead ua lattice thiab interatomic nrug nyob rau hauv nws.
• Qhov loj ntawm ib lub atomChemical Element.

Cov lus ntawm cov hlau thiab lwm cov ntsiab lus tau muab hauv qab no.

Ntawm no yog cov duab hauv g/cm3. Nyob rau hauv thiaj li yuav cov hlau ntom cov lus qhia nyob rau hauv kg / m3, nws yog ib qhov tsim nyog yuav tau muab cov nqi sib xws los ntawm 1000. Cov lus qhia tias cov hlau muaj qhov sib txawv heev. Lawv tuaj yeem sib dua li dej (sodium, lithium, potassium) lossis hnyav heev (iridium, osmium, platinum, kub).

Density of alloys

Alloys yog cov khoom siv ntau yam, piv txwv li, hlau yog cov hlau thiab carbon. Cov qauv siv lead ua ntawm cov alloys yog ntau dua li cov hlau ntshiab. Rau cov hlau, uas muaj cov hlau thiab cov pa roj carbon atoms, muaj ntau txoj hauv kev rau lawv cov kev sib koom ua ke (khoom tov ntawm carbon hauv bcc los yog fcc hlau, tsim cov theem tshwj xeeb - cementite, tsim cov graphite inclusions, thiab lwm yam).

Raws li qhov ntom ntawm cov alloys, feem ntau nws tuaj yeem kwv yees siv cov qauv yooj yim hauv qab no:

ρ=∑_im_i/∑_iV _i.

Qhov twg kuv yog tus naj npawb ntawm cov khoom hauv cov hlau. Yog tias qhov kev qhia no tau siv rau ob lub ntsiab lus alloy, ces cov qauv hauv qab no tuaj yeem tau txais:

ρ=ρ₁ρ₂/(ρ₁+x(ρ₂-ρ_1)).

Qhov twg ρ₁ thiab ρ_{2 yog qhov ntom ntom ntawm cov khoom sib txuas, x yog qhov loj ntawm cov khoom hauv thawj zaug. hlau alloy. Nws yog txhaisyog li:}

x=m₁/(m₁+ m_2).

Table ntawm qhov ntom ntawm qee cov alloys hauv tons ib cubic meter tau muab hauv qab no.

Vim tias txhua lub alloy muaj feem ntau ib feem (steel - hlau, bronze - tooj liab, nichrome - npib tsib xee, thiab lwm yam), nws tsis yog qhov xav tsis thoob tias lawv qhov ntom ntom yog ze rau cov hlau ntshiab.