Cov nyhuv ntawm kev kho cryogenic ntawm microstructure ntawm cemented carbide

Cov txheej txheem cryogenic sib txawv ua rau muaj kev hloov pauv hauv cov khoom ntawmcemented carbide, thiab cov kev hloov hauv cov khoom muaj feem cuam tshuam nrog kev hloov pauv ntawm nws cov microstructure.Yog li ntawd, nws yog ib qho tsim nyog yuav tau soj ntsuam ntxiv qhov cuam tshuam ntawm kev kho cryogenic ntawm microstructure ntawm cemented carbide.

Cov txheej txheem microstructure ntawm WC-Co cemented carbide yog raws li nram no: ib theem - WC (theem nyuaj);β theem - Co (binder theem);y theem - (TaC, TiC, NbC, WC) equicubic lattice mixed carbides;eta-decarburized theem (CoW, C, Co. W. C).Gill et al.muab ib daim duab schematic ntawm a thiab β theem, raws li qhia hauv daim duab 6. Ntawm lawv, α theem-WC (theem nyuaj) occupies lub ntsiab ntawm lubcemented carbide khoomnyob rau hauv daim ntawv ntawm ib tug txhav pob txha, thaum lub sij hawm β-theem-Co (binder theem) yog sib txuas nrog tungsten carbide (WC) zoo li ib daim phiaj.

Thaum cov cemented carbide txias tom qab sintering, vim muaj ntau ntawm W thiab C yog yaj hauv Co, qhov kub-kub theem α-Co ntawm chav tsev kub tseem nyob ruaj khov.Thaum qhov kub thiab txias txuas ntxiv mus, lub martensitic theem transformation ntawm lub ntsej muag-centered cubic α-Co mus rau kaw-packed hexagonal ε-Co tshwm sim nyob rau hauv lub tsev cog khoom theem -Co.Nws tuaj yeem pom tias thaum kub hloov pauv, muaj kev hloov pauv hauv microstructure ntawmcemented carbide, uas muab qhov ua tau rau kev kho mob cryogenic los txhawb kev hloov pauv ntawm theemcemented carbide.Ntau qhov kev tshawb fawb tau tsom mus rau qhov kev hloov pauv hauv microstructure ntawmcemented carbideua ntej thiab tom qab kev kho mob cryogenic thiab tshawb xyuas lub tshuab microscopic evolution mechanism thaum lub macroscopic zog hloov.