Abubuwan da ke cikin carbon na kowane nau'i na nau'i na nau'i na nau'i na nau'i daban-daban, tare da abun ciki na carbon A-2.5 awt.% a cikin wannan kewayon, yana samar da wani abu mai yawa wanda kusan babu pores, wanda ya ƙunshi nau'i-nau'i na silicon carbide da aka rarraba da kuma silicon kyauta. Tare da haɓakar ƙari na carbon, abun ciki na silicon carbide mai amsawa yana ƙaruwa sannu a hankali, girman ƙwayar siliki na siliki yana ƙaruwa, kuma ana haɗa silicon carbide tare da juna a cikin siffar kwarangwal. Duk da haka, yawan abin da ke cikin carbon zai iya haifar da saura carbon a cikin jikin da ba a so. Lokacin da aka ƙara baƙar fata na carbon zuwa 3a, ƙaddamarwar samfurin bai cika ba, kuma baƙar fata "interlayers" suna bayyana a ciki.
Lokacin da carbon ke amsawa tare da narkakkar siliki, ƙimar girman girmansa shine 234%, wanda ke sanya microstructure na silicon carbide mai amsawa mai alaƙa da abun cikin carbon a cikin billet. Lokacin da abun ciki na carbon a cikin billet ya yi ƙanƙara, siliki carbide da aka samar ta hanyar siliki-carbon dauki bai isa ya cika ramukan da ke kewaye da foda carbon ba, yana haifar da adadi mai yawa na silicon kyauta a cikin samfurin. Tare da karuwar abun ciki na carbon a cikin billet, silicon carbide mai ɗaukar hoto na iya cika pores a kusa da foda carbon kuma ya haɗa ainihin siliki carbide tare. A wannan lokacin, abun ciki na siliki na kyauta a cikin samfurin yana raguwa kuma yawan ƙwayar jikin da aka lalata yana ƙaruwa. Koyaya, lokacin da akwai ƙarin carbon a cikin billet ɗin, silicon carbide na biyu da aka haifar ta hanyar amsawa tsakanin carbon da silicon da sauri yana kewaye da toner, yana sa da wahala ga narkakkar siliki don tuntuɓar toner, yana haifar da ragowar carbon a cikin jikin da aka lalata.
Dangane da sakamakon XRD, abun da ke ciki na lokaci-lokaci na sic sic shine α-SiC, β-SiC da silicon kyauta.
A cikin aiwatar da yawan zafin jiki na zafin jiki, ƙwayoyin carbon suna ƙaura zuwa yanayin farko akan SiC surface β-SiC ta narkakkar siliki α-secondary samuwar. Tun da silica-carbon dauki shi ne na hali exothermic dauki tare da babban adadin dauki zafi, m sanyaya bayan wani ɗan gajeren lokaci na maras wata-wata high zafin jiki dauki ƙara da susaturation na carbon narkar da a cikin ruwa silicon, sabõda haka, β-SiC barbashi precipitated a cikin nau'i na carbon, don haka inganta kayan aikin injiniya na kayan. Saboda haka, na biyu β-SiC gyare-gyaren hatsi yana da amfani ga inganta ƙarfin lankwasawa. A cikin tsarin haɗin gwiwar Si-SiC, abubuwan da ke cikin siliki na kyauta a cikin kayan yana raguwa tare da karuwar abun ciki na carbon a cikin albarkatun kasa.
Ƙarshe:
(1) Danko na shirye-shiryen reactive sintering slurry yana ƙaruwa tare da karuwar adadin baƙar fata na carbon; Ƙimar pH shine alkaline kuma a hankali yana ƙaruwa.
(2) Tare da haɓakar abun ciki na carbon a cikin jiki, ƙima da ƙarfin lanƙwasawa na yumbura mai ɗaukar hoto wanda aka shirya ta hanyar latsawa ya fara ƙaruwa sannan ya ragu. Lokacin da adadin baƙar fata na carbon ya kasance sau 2.5 na adadin farko, ƙarfin lanƙwasawa mai maki uku da yawa mai yawa na billet kore bayan ɓacin rai yana da girma sosai, waɗanda sune 227.5mpa da 3.093g/cm3, bi da bi.
(3) Lokacin da jikin da ke da carbon da yawa ya ɓace, tsagewa da wuraren "sandwich" baƙar fata za su bayyana a jikin jiki. Dalilin fashewar shine iskar silicon oxide da ake samarwa a cikin tsarin amsawa ba ta da sauƙin fitarwa, sannu a hankali, matsa lamba yana tashi, kuma tasirin sa na jack yana haifar da tsagewar billet. A cikin baƙar fata "sanwici" a cikin sinter, akwai adadi mai yawa na carbon wanda ba ya shiga cikin amsawa.
Lokacin aikawa: Yuli-10-2023