Lub hauv paus ntsiab lus ntawm pob zeb diamond mulching txheej los txhim kho lub peev xwm ntawm pob ntxig

1. Kev tsim cov carbide-coated pob zeb diamond

Lub hauv paus ntsiab lus ntawm kev sib xyaw cov hmoov hlau nrog pob zeb diamond, cua sov rau qhov ntsuas kub thiab rwb thaiv tsev rau qee lub sijhawm hauv lub tshuab nqus tsev. Nyob rau ntawm qhov kub no, lub vapor siab ntawm cov hlau yog txaus los npog, thiab tib lub sijhawm, cov hlau yog adsorbed ntawm pob zeb diamond nto los tsim cov pob zeb diamond coated.

2. Kev xaiv cov hlau coated

Txhawm rau ua kom lub pob zeb diamond txheej ruaj khov thiab txhim khu kev qha, thiab kom nkag siab zoo dua ntawm cov txheej txheem txheej txheej ntawm cov txheej txheem quab yuam, cov txheej hlau yuav tsum tau xaiv. Peb paub tias pob zeb diamond yog ib qho alloomorphism ntawm C, thiab nws cov lattice yog ib txwm tetrahedron, yog li lub hauv paus ntsiab lus ntawm txheej txheej hlau yog tias cov hlau muaj kev sib raug zoo rau carbon. Nyob rau hauv txoj kev no, nyob rau hauv tej yam kev mob, tshuaj lom neeg kev sib raug zoo tshwm sim nyob rau hauv lub interface, tsim ib tug ruaj khov daim ntawv cog lus, thiab ib tug Me-C membrane yog tsim. Lub infiltration thiab adhesion txoj kev xav nyob rau hauv lub pob zeb diamond-hlau system taw qhia hais tias cov tshuaj sib cuam tshuam tshwm sim tsuas yog thaum lub adhesion ua hauj lwm AW> 0 thiab ncav cuag ib tug tej yam nqi. Lub sij hawm luv luv ntawm pawg B hlau ntsiab lus nyob rau hauv lub sij hawm lub sij hawm, xws li Cu, Sn, Ag, Zn, Ge, thiab lwm yam. muaj tsis zoo affinity rau C thiab tsis adhesion ua hauj lwm, thiab cov bonds tsim yog molecular bonds uas tsis muaj zog thiab yuav tsum tsis txhob xaiv; cov hlau hloov pauv nyob rau hauv lub sij hawm ntev, xws li Ti, V, Cr, Mn, Fe, thiab lwm yam, muaj cov adhesion loj ua hauj lwm nrog cov kab ke ntawm C. Kev sib cuam tshuam ntawm C thiab cov hlau hloov pauv tau nce nrog cov d txheej electrons, yog li Ti thiab Cr yog qhov tsim nyog rau kev npog cov hlau.

3. Kev sim teeb

Thaum qhov kub ntawm 8500C, pob zeb diamond tsis tuaj yeem ncav cuag lub zog dawb ntawm cov pa roj carbon atoms ntawm lub pob zeb diamond nto thiab cov hmoov hlau los ua cov hlau carbide, thiab tsawg kawg 9000C kom ua tiav lub zog xav tau rau kev tsim cov hlau carbide. Txawm li cas los xij, yog tias qhov kub thiab txias dhau lawm, nws yuav ua rau thermal burning poob rau pob zeb diamond. Xav txog qhov cuam tshuam ntawm kev ntsuas qhov ntsuas kub thiab lwm yam, cov txheej txheem ntsuas kub yog teem rau ntawm 9500C. Raws li tuaj yeem pom los ntawm kev sib raug zoo ntawm lub sijhawm rwb thaiv tsev thiab cov tshuaj tiv thaiv ceev (hauv qab),? Tom qab ncav cuag lub zog dawb ntawm cov hlau carbide tiam, cov tshuaj tiv thaiv pib sai sai, thiab nrog rau tiam ntawm carbide, cov tshuaj tiv thaiv yuav maj mam qeeb. Tsis muaj qhov tsis ntseeg tias nrog lub sijhawm txuas ntxiv ntawm rwb thaiv tsev, qhov ntom thiab zoo ntawm txheej yuav raug txhim kho, tab sis tom qab 60 feeb, qhov zoo ntawm txheej tsis cuam tshuam zoo heev, yog li peb teem lub sijhawm rwb thaiv tsev li 1 teev; qhov siab dua lub tshuab nqus tsev, qhov zoo dua, tab sis txwv rau qhov kev sim, peb feem ntau siv 10-3mmHg.

Package inset peev xwm txhim kho txoj cai

Cov txiaj ntsig ntawm kev sim qhia tau hais tias lub cev xeeb tub muaj zog dua rau cov pob zeb diamond coated dua li cov pob zeb diamond uas tsis muaj coated. Yog vim li cas rau qhov muaj peev xwm muaj peev xwm ntawm lub cev xeeb tub rau lub pob zeb diamond coated yog tias, tus kheej, muaj qhov tsis xws luag thiab micro-cracks ntawm qhov chaw lossis sab hauv ntawm cov pob zeb tsis muaj pob zeb diamond. Vim tias muaj cov microcracks no, lub zog ntawm pob zeb diamond txo qis, ntawm qhov tod tes, C lub ntsiab ntawm pob zeb diamond tsis tshua muaj tshwm sim nrog cov khoom hauv lub cev hauv plab. Yog li ntawd, lub log tsheb lub cev ntawm lub pob zeb diamond uncoated yog purely ib tug neeg kho tshuab extrusion pob, thiab hom ntawm pob ntxig no tsis tshua muaj zog. Thaum lub load, cov saum toj no microcracks yuav ua rau lub concentration ntawm kev ntxhov siab, uas ua rau poob ntawm lub pob insert muaj peev xwm. Cov ntaub ntawv ntawm overburden pob zeb diamond sib txawv, vim yog plating ntawm ib tug hlau zaj duab xis, lub pob zeb diamond lattice defects thiab micro tawg tau sau, ntawm ib sab, lub zog ntawm coated pob zeb diamond yog nce, ntawm qhov tod tes, ntim nrog micro tawg, tsis muaj kev ntxhov siab concentration tshwm sim. Qhov tseem ceeb tshaj, qhov infiltration ntawm cov hlau bonded nyob rau hauv lub log tsheb yog hloov dua siab tshiab rau hauv cov pa roj carbon ntawm lub pob zeb diamond nto. Qhov tshwm sim yog cov hlau sib txuas ntawm pob zeb diamond wetting lub kaum ntse ntse los ntawm ntau dua 100 o mus rau tsawg dua 500, zoo heev txhim kho cov hlau sib txuas rau pob zeb diamond wetting, ua rau lub log tsheb ntawm cov pob zeb diamond npog teeb tsa los ntawm thawj extrusion mechanical pob rau hauv cov pob zeb sib txuas, uas yog lub npog pob zeb diamond thiab lub log lub cev daim ntawv cog lus, yog li txhim kho lub fetal lub cev.

Pob insetting muaj peev xwm. Nyob rau tib lub sijhawm, peb kuj ntseeg hais tias lwm yam xws li sintering tsis, coated pob zeb diamond particle loj, qib, fetal lub cev particle loj thiab thiaj li nyob rau muaj tej yam cuam tshuam rau lub pob ntxig quab yuam. Qhov tsim nyog sintering siab tuaj yeem ua rau kom nrawm nrawm thiab txhim kho qhov nyuaj ntawm lub cev hauv plab. Tsim nyog sintering kub thiab rwb thaiv tsev lub sij hawm yuav txhawb lub siab kub tshuaj tiv thaiv ntawm lub log tsheb lub cev muaj pes tsawg leeg thiab coated hlau thiab pob zeb diamond, yog li ntawd lub pob zeb diamond daim ntawv cog lus yog ruaj khov, lub pob zeb diamond qib yog zoo, cov siv lead ua qauv zoo sib xws, cov theem zoo sib xws yog soluble, thiab cov pob teeb yog zoo dua.

Sau los ntawm Liu Xiaohui