Kev tshuaj xyuas cov hlau thiab alloys: nta, piav qhia thiab yuav tsum tau ua

2024 Tus sau: Howard Calhoun | [email protected]. Kawg hloov kho: 2023-12-17 10:28

Kev paub ntawm cov hlau yog siv rau hauv kev txiav txim plaub ntug, hauv kev tshawb xyuas qhov ua rau muaj xwm txheej, nrog rau kev txiav txim siab txog kev ua haujlwm hauv kev tsim khoom ntawm ntau yam khoom. Ib qho tshwj xeeb ntawm cov hlau thiab alloys yog tias lawv zoo "tshem" cov kev txwv ntawm lub xeev yav dhau los uas tau tshwm sim nyob rau hauv kev cuam tshuam ntawm cov khoom siv sab nraud (cov khoom siv tshuab, cov teebmeem thermal, thiab lwm yam). Cov cuab yeej no tso cai rau koj los teeb tsa cov xwm txheej uas tshwm sim ua ntej thiab txheeb xyuas qhov kev sib raug zoo.

Tasks

Txhua txoj haujlwm ntawm kev txawj ntse metallurgical tuaj yeem ua ke ua 3 pawg loj:

• Kev faib tawm - kev txiav txim siab ntawm txhua yam (hom hlau lossis hlau, qib, kev ua haujlwm; tso nyiaj los ntawm cov khoom raug rho tawm; ua raws li qhov yuav tsum tau ua ntawm daim duab kos thiab lwm yam ntaub ntawv qhia kev).
• Kev txheeb xyuas tus neeg: kev txiav txim siab ntawm tag nrho cov khoom hauv qhov chaw (los ntawm cov cim ntawm cov khoom muaj pes tsawg leeg thiab cov qauv, cov cim ntawm kev ua haujlwm thiab lwm yam tsis muaj), koom nrog cov khoom tsim tawm, tsim kom muajqhov chaw - khoom siv lossis chaw tsim khoom; pab pawg - txheeb xyuas cov khoom zoo ib yam ntawm cov hlau thiab alloys los ntawm cov yam ntxwv tshwj xeeb (cov yam ntxwv impurities, qauv siv lead ua, cov khoom siv kho tshuab, xwm txheej ntawm kev puas tsuaj, qhov chaw saum npoo: oxidation, corrosion, khawb, thiab lwm yam).
• Diagnostic: tsim kom muaj qhov tseeb ntawm kev sib cuam tshuam nrog ib feem ntawm cov hlau, qhov ua rau thiab cov yam ntxwv ntawm cov txheej txheem kev puas tsuaj, txiav txim siab cov cuab yeej tsim khoom, hom khoom siv uas cov khoom siv hlau tau tsim, txheeb xyuas qhov sib txawv ntawm qhov yuav tsum tau ua. kev cai lij choj.

khoom

Cov nram qab no micro- thiab macro-cov ncauj lus tuaj yeem ua cov khoom ntawm kev kuaj xyuas cov khoom hlau:

• hlau qhov chaw, qhov khoob, xaim thiab xaim, hlau hoses, cables, kav dej;
• melting ntawm cov xov hlau thiab lwm yam khoom hlau;
• nthuav dav ntawm lub tsheb thiab cov cuab yeej siv thev naus laus zis raug rhuav tshem vim qhov xwm txheej;
• riam (lub Hoobkas thiab ua hauv tsev) thiab lwm yam riam phom edged;
• tawg lossis ntu ntawm cov khoom tawg;
• solders;
• jewellery, precious hlau thiab ib txwm kub;
• metallization traces;
• khoom siv hauv tsev.

Kev tshuaj xyuas cov hlau thiab cov hlau yog ua raws li cov qauv hauv qab no los txiav txim cov yam ntxwv:

• khoom xwm (qhov ntom ntom, ferromagnetism, xim, hardness, metallic luster, hluav taws xob conductivity, cuam tshuam nrog acids);
• geometric thiabtsim nta (loj, puab, muaj hlau thiab non-metallic coatings);
• siv tshuab thiab khoom siv;
• kev ua haujlwm (hnav, corrosion, thiab lwm yam);
• kev puas tsuaj nta (melting, deformation, poob siab lossis zoo li qub loads, yaig, ua ke ntawm ntau yam);
• hom kev faib tawm thiab kev ua haujlwm;
• microstructure;
• lub cev thiab cov khoom siv kho tshuab, tshuaj muaj pes tsawg leeg.

Nyob ntawm cov lus nug twg tau muab tso ua ntej kev xeem, kev tsim kho cov txheej txheem kev xeem nyob ntawm. Txij li qee txoj kev kawm xav tau kev puas tsuaj ntawm cov khoom nyob rau hauv kev kawm, nws yog ib qho tsim nyog los tsim kom meej lub hom phiaj ntawm txoj kev kawm.

Metal Forensics

Kev tshuaj ntsuam xyuas yog ua los daws cov teeb meem ntau tshaj hauv qab no:

• txiav txim siab hom hlau los ntawm kev ua txhaum riam phom;
• txheeb xyuas hom kub - haiv neeg lossis kev lag luam;
• muaj hlau hais rau lwm yam khoom;
• txiav txim siab qhov tseeb ntawm npib lossis khoom plig, nrog rau lawv lub hnub nyoog;
• kuaj pom ntawm hom thiab lub sijhawm raug rau cov hlau;
• yog vim li cas rau kev puas tsuaj ntawm ib feem ntawm cov hlau los yog kev sib sau ua ke (kom xaus lus thaum muaj xwm ceev, hluav taws kub);
• txiav txim siab tus kheej ntawm ntu thiab lub ntsiab hlau / qauv, nrog rau cov qauv uas lawv tau sib cais thiab lwm tus.

kho qhov muag thiab tshuaj ntsuam xyuas microscopy

Kev tshuaj xyuas microscopic ntawm qhov chaw yog ua tiav ntawm thawj theem ntawm kev txawj ntse metallurgy. Kev soj ntsuam ntawm cov hlau thiab alloys qhia cov yam ntxwv tsim nyob rau hauv cov txheej txheem ntawm kev tsim khoom thiab kev ua haujlwm ntawm cov khoom thiab cov khoom sib dhos. Txhawm rau ua tiav txoj haujlwm no, siv cov tshuab ntsuas hluav taws xob thiab xa hluav taws xob xa mus.

Ib yam ntawm cov kev ntsuam xyuas no yog fractography - kev tshawb fawb me me ntawm cov pob txha tawg los tsim kom muaj kev sib raug zoo ntawm cov cim ntawm kev puas tsuaj thiab sab nraud lossis sab hauv uas ua rau kev puas tsuaj.

Tshuaj muaj pes tsawg leeg tshawb fawb

Txoj kev siv ntau tshaj plaws rau kev kawm cov tshuaj muaj pes tsawg leeg ntawm cov hlau thiab cov hlau yog emission spectral analysis (ESA), uas yog ua raws li cov yam ntxwv ntawm emission spectrum ntawm atoms ntawm cov teeb meem nyob rau hauv lub optical ntau yam ntawm electromagnetic tsis. Lub teeb emission zoo siab los ntawm lub txim tawm ntawm cov khoom siv hlau kawm thiab cov khoom siv hluav taws xob.

Txoj kev no tso cai rau koj los txiav txim siab txog tshuaj lom neeg nyob rau hauv qhov muaj nws qhov tsawg tshaj plaws (txog 10 -4 %), uas yog siv rau hauv kev tshuaj xyuas cov lej ntawm ob qho tib si metallic thiab non-metallic contacting khoom. Cov txheej txheem no kuj tseem siv rau hauv kev tshuaj xyuas qhov zoo ntawm cov hlau los txheeb xyuas cov microimpurities uas tsis raug tswj hwm los ntawm cov kev qhia tshwj xeeb rau kev tsim cov khoom no.

Txoj kev tshawb fawb tsis muaj kev puas tsuaj thiab classical

Yog xav tau kev tshawb fawbTxoj kev tsis muaj kev puas tsuaj, ces nws yog ua tiav siv X-ray fluorescence tsom xam. Cov thev naus laus zis no suav nrog cov khoom siv rau X-rays, uas ua rau muaj hluav taws xob fluorescent hauv txheej txheej saum npoo. Txhua tus lej atomic ntawm lub sijhawm ua haujlwm ntawm cov tshuaj lom neeg muaj nws tus kheej wavelength. Cov txheej txheem no yuav pab txiav txim siab qhov zoo thiab qhov muaj pes tsawg leeg.

Kev kuaj xyuas cov hlau tuaj yeem ua tiav hauv txoj kev classical. Lawv siv sij hawm ntev dua thiab xav tau ntau qhov qauv. Cov txheej txheem no suav nrog:

• zoo tshuaj tiv thaiv;
• tshuaj ntsuam colorimetric;
• polarography;
• conductometry (kev ntsuas ntawm hluav taws xob conductivity ntawm kev daws) thiab lwm yam.

Kev tshawb fawb Microstructure

Cov qauv metallography yog siv los txiav txim qhov xwm txheej thiab cov theem hauv kev kuaj xyuas cov hlau tsis muaj hlau, hlau, cam khwb cia hlau thiab lwm yam hlau. Txoj kev tshawb no yog ua los ntawm txoj kev ntawm cov hmoov x-ray diffraction. Cov qauv yog hauv av rau hauv cov hmoov, ib tug monochromatic X-ray beam yog qhia ntawm nws, thiab ib tug duab yog tau nyob rau hauv daim ntawv ntawm rings ntawm ib tug yees duab zaj duab xis dov ib ncig ntawm cov khoom nyob rau hauv kev kawm. Lub xub ntiag ntawm ib qho kev ntxhib los mos tau tshwm sim los ntawm kev hloov pauv ntawm qhov siv ntawm cov kab.

Tshwj xeeb X-ray diffractometers yog siv los kawm cov hmoov X-ray qauv. Lawv kuj tuaj yeem siv tau kom tau txais cov ntaub ntawv hais txog cov qauv siv lead ua ntawm cov hlau. ATHauv cov ntsiab lus siv tau, qhov no yog siv los txiav txim seb hom kev kho cua sov.

Kev txiav txim siab ntawm theem muaj pes tsawg leeg yog qhov tsim nyog los txheeb xyuas qhov dav dav ntawm cov khoom ntawm cov khoom hauv kev kawm. Xws li kev kawm, piv txwv li, tso cai rau koj kom tau txais cov ntaub ntawv hais txog dab tsi yog qhov tseem ceeb - luv luv Circuit Court lossis hluav taws kub (tooj liab hu), seb lub teeb nrog lub tungsten filament hlawv thaum lub sijhawm nws puas tsuaj, thiab daws lwm yam teeb meem.

txhawm rau txheeb xyuas cov yeeb yaj kiab nyias ntawm oxides, carbides, chlorides, sulfides thiab lwm yam ntsev ntawm cov khoom hlau, siv txoj kev diffraction electron. Nws yog nyob ntawm qhov sib txawv ntawm cov kwj ntawm cov hluav taws xob txav, lub wavelength uas luv dua li ntawm X-rays. Kev tsom xam ntawm cov hlau thiab alloys yog ua nyob rau hauv lub tshuab nqus tsev electron diffraction, uas tseem tuaj yeem tsim cov duab ntxoov ntxoo electron-optical.

Mechanical Properties

Txhawm rau txiav txim siab lub cev thiab lub zog ntawm cov hlau thiab cov hlau, cov kev sim hauv qab no yog siv:

• rau nro / compression (kev txiav txim siab ntawm tensile lub zog, elasticity, ntws thiab lwm yam ntxwv);
• bending;
• rau hardness thiab microhardness;
• cua sov kom pom qhov kub ntawm theem hloov pauv, thermal conductivity thiab linear expansion.

Cov kev zoo li no feem ntau yog siv ua ke thaum tshawb xyuas qhov ua rau muaj xwm txheej thiab kev puas tsuaj ntawm cov hlau thiab cov khoom sib dhos.

Kev xav

Tom qab kev tshuaj xyuas cov hlau, tus kws tshaj lij tshaj tawm cov lus xaus uas muaj cov ntaub ntawv hauv qab no:

• cov ntaub ntawv dav dav (npe ntawm cov ntawv tshawb fawb, hnub pib thiab hnub kawg, qhov chaw kuaj, thaj chaw rau nws ua tiav, cov ntaub ntawv hais txog tus kws tshaj lij, cov lus nug);
• txoj kev siv thiab cov qauv kev tshawb fawb dav dav raws li kev ua haujlwm tiav;
• cov ntaub ntawv tseem ceeb thiab lwm qhov chaw;
• cov ntaub ntawv tau txais thaum kawm ntawm cov khoom;
• xaus lus (lossis yog vim li cas vim li cas thiaj tsis tuaj yeem muab cov lus teb meej).

Examples

Piv txwv ntawm cov kws tshaj lij kev xav suav nrog cov hauv qab no:

• kev puas tsuaj ntawm qhov tshwm sim los ntawm qhov kev txiav txim ntawm qhov zoo li qub bending load ua ib txhij;
• qhov tsis ua tiav ntawm lub rooj sib txoos yog ob-theem: tom qab ib qho kev thauj khoom zoo ib yam, qhov tawg tau tsim, uas tau nce los ntawm 80% raws li qhov tshwm sim ntawm kev qaug zog; cov khoom raug muab faib ua ntu nyob rau hauv qhov kev txiav txim ntawm qhov zoo li qub tensile load raws thaj tsam tsis muaj zog los ntawm qhov tawg no;
• kev puas tsuaj ntawm lub nkoj tau tshwm sim raws li qhov vuam, uas tsis muaj zog los ntawm qhov tsis xws luag thaum vuam (tsis muaj qhov nkag ntawm lub hauv paus ntawm lub seam), thaum lub sijhawm pib ua haujlwm, cov khoom tsis muaj lawm. lub zog tsim nyog;
• qhov tsis ua tiav ntawm cov qauv yog tam sim ntawd, los ntawm riveting, yog vim li cas yog qhov cuam tshuam ntawm kev thauj khoom dynamic, tus nqi ntawm ntau tshaj lub zog nteg nyob rau hauv cov ntaub ntawv tsim.

Los ntawm rooj plaub ntawm kev txiav txim plaub ntug,piv txwv li daim ntawv thov kev ntsuam xyuas ntawm cov hlau, peb tuaj yeem hais cov hauv qab no: ib qho hlau tawg tau pom nyob rau hauv lub cev ntawm cov neeg tua neeg. Nws yog ib qho tsim nyog los tsim kom tau qhov twg ntawm 3 rab riam nws yog ib feem ntawm. Spectral tsom xam pom tias muaj pes tsawg leeg ntawm cov fragment coincided nrog rau ntawm ib tug riam. Lub microstructure ntawm daim hlau txawv ntawm txhua cov hniav, tab sis thaum lub sij hawm ntsuam xyuas nws tau ua pov thawj tias cov hniav yog sharpened rau ntawm ib tug hluav taws xob grinder tsis txias, vim hais tias ntawm cov kev hloov no tshwm sim.

Laboratories

Kev tshuaj xyuas tus kheej ntawm cov hlau tuaj yeem ua los ntawm cov chaw kuaj mob nrog lub xeev lees paub. Daim ntawv pov thawj kev lees paub yuav tsum qhia txog qhov kev tso cai ntawm kev ua haujlwm tau txais los ua kev tshawb fawb, kev sim thiab cov ntaub ntawv tswj hwm raws li lawv tau ua, nrog rau cov lus teev tseg ntawm lub rooj sib tham ntawm Pawg Neeg Saib Xyuas Kev lees paub.

Hauv cheeb tsam Moscow, cov kev pabcuam no yog muab los ntawm Metall-Expertise, Interregional Center for Expertise and Evaluation (ICEA), Federation of Forensic Experts thiab lwm lub koom haum.