Duk wanda ya taɓa yin aiki a masana'antar goge-goge, ko kuma masana'antar refractories, ko kuma yumbu ya san cewakore silicon carbideMicropowder yana da matuƙar wahalar aiki da shi. Wannan kayan, wanda yake da tauri kusa da lu'u-lu'u da kuma kyakkyawan yanayin zafi da wutar lantarki, ya dace da niƙa daidai, ƙarfin juriya, da yumbu na musamman. Duk da haka, la'akari da taurinsa bai isa a yi amfani da shi yadda ya kamata ba - akwai abubuwa da yawa da suka fi wannan foda mai launin kore fiye da yadda aka zata. Mabuɗin shine "girman ƙwayoyin cuta."
Masana injiniyan kayan aiki masu ƙwarewa kan ce, "Lokacin da ake kimanta abu, da farko a duba foda; lokacin da ake kimanta foda, da farko a duba barbashi." Wannan gaskiya ne. Girman barbashi na micropowder na silicon carbide kore yana ƙayyade kai tsaye ko zai zama kadara mai ƙarfi ko babban cikas a aikace-aikacen ƙasa. A yau, za mu bincika yadda ake sarrafa wannan girman barbashi da ƙalubalen fasaha da ke tattare da cimma wannan iko.
I. "Nika" da "Rabuwa": Tsarin "Tiyata" na Matakin Micron-Level
Don samun kyakkyawan sakamakofoda mai siffar silicon carbide kore, mataki na farko shine a "rushe" manyan lu'ulu'u masu launin kore na silicon carbide. Wannan ba abu ne mai sauƙi ba kamar a buge su da guduma, amma tsari ne mai laushi wanda ke buƙatar cikakken daidaito.
Babban hanyar ita ce niƙa ta inji. Duk da cewa tana da ƙarfi, amma ta ƙunshi kulawa mai kyau. Injin niƙa ƙwallo shine "wurin horo" da aka fi amfani da shi, amma amfani da ƙwallan ƙarfe na yau da kullun na iya haifar da ƙazanta na ƙarfe cikin sauƙi. Hanyoyi masu ci gaba yanzu suna amfani da rufin yumbu da ƙwallan niƙa silicon carbide ko zirconia don tabbatar da tsarki. Niƙa ƙwallo kaɗai bai isa ba; don samun ƙaramin foda mai kyau da daidaito, musamman a cikin kewayon micrometer na ƙasa da 10 (µm), ana amfani da "niƙa ƙwallo mai saukar ungulu". Wannan dabarar tana amfani da iska mai sauri don sa barbashi su yi karo da karyewa, wanda ke haifar da ƙarancin gurɓatawa da kuma rarrabawar girman barbashi mai kunkuntar. Niƙa danshi yana shiga cikin aiki lokacin da ake buƙatar foda mai laushi (misali, ƙasa da µm). Yana hana haɗuwa da foda yadda ya kamata, yana haifar da slurries tare da mafi kyawun watsawa.
Duk da haka, kawai "rushewa" bai isa ba; ainihin fasahar asali tana cikin "rarrabawa." Foda da ake samarwa ta hanyar niƙawa ba makawa ta bambanta a girma, kuma burinmu shine mu zaɓi girman da ake so kawai. Wannan kamar ɗaukar ƙwayoyin yashi ne kawai waɗanda diamitansu ya kai milimita 0.5 zuwa 0.6 daga tarin yashi. Injinan rarraba busassun iska a halin yanzu sune aka fi amfani da su, suna amfani da ƙarfin centrifugal da aerodynamics don raba foda mai kauri da laushi tare da babban inganci da babban fitarwa. Amma akwai kama: lokacin da foda ya yi kyau sosai (misali, ƙasa da ƙananan micrometers), ƙwayoyin suna taruwa tare saboda ƙarfin van der Waals (agglomeration), wanda ke sa ya yi wa masu rarraba iska wahala su raba su daidai bisa ga girman barbashi ɗaya. A wannan yanayin, rarrabuwar danshi (kamar rarrabuwar centrifugal sedimentation) wani lokacin na iya zama da amfani, amma tsarin yana da rikitarwa kuma farashin yana ƙaruwa.
Don haka, ka gani, dukkan tsarin sarrafa girman barbashi a zahiri gwagwarmaya ce da sulhu tsakanin "rushewa" da "rarrabawa." Manufar murƙushe barbashi masu ƙanƙanta, amma barbashi masu ƙanƙanta suna da saurin taruwa, wanda ke hana rarrabuwa; rarrabuwa tana nufin mafi daidaito, amma sau da yawa tana fama da ƙurar da aka tara. Injiniyoyi suna ɓatar da mafi yawan lokacinsu suna daidaita waɗannan buƙatu masu karo da juna.
II. "Matsaloli" da "Mafita": Ƙayayuwa da Haske a Hanyar Sarrafa Girman Ƙwayoyin Cuku
Sarrafa girman ƙwayoyin cuta na ƙwayoyin cuta na silicon carbide mai launin kore ya ƙunshi fiye da kawai niƙawa da rarraba su. Akwai wasu "cikakkun" da ke hana hanya, kuma ba tare da magance su ba, ba zai yiwu a sarrafa su daidai ba.
Babban cikas na farko shine koma bayan da "taurin kai" ya haifar.Koren silicon carbideyana da matuƙar wahala, yana buƙatar kuzari mai yawa don murƙushewa, wanda ke haifar da lalacewar kayan aiki. A lokacin niƙa mai kyau, lalacewar kayan niƙa da linings yana haifar da adadi mai yawa na datti. Waɗannan ƙazanta suna haɗuwa cikin samfurin, suna lalata tsarkinsa. Duk aikinku na sarrafa girman barbashi ya zama ba shi da amfani idan matakan ƙazanta sun yi yawa. A halin yanzu, masana'antar tana haɓaka kayan niƙa da kayan linings masu jure lalacewa, da inganta tsarin kayan aiki, duk don magance wannan "damisar mai tauri."
Damisa ta biyu ita ce "dokar jan hankali" a duniyar foda mai kyau - haɗuwa. Mafi ƙanƙantar ƙwayoyin, mafi girman takamaiman yankin saman, kuma mafi girman kuzarin saman; a dabi'ance suna "ƙunƙulewa tare." Wannan haɗuwa na iya zama "ƙunƙulewa mai laushi" (wanda ƙarfin tsakanin ƙwayoyin halitta, kamar ƙarfin van der Waals, waɗanda suke da sauƙin wargajewa), ko kuma mafi girman "ƙunƙulewa mai ƙarfi" (inda a lokacin niƙa ko ƙunƙulewa, saman ƙwayoyin cuta yana narkewa kaɗan ko kuma yana fuskantar halayen sinadarai, yana haɗa su sosai). Da zarar ƙunƙulewa suka yi girma, suna bayyana a matsayin "manyan ƙwayoyin cuta" a cikin kayan aikin nazarin girman ƙwayoyin cuta, suna ɓatar da hukuncinka sosai; a aikace-aikace, kamar a cikin goge ruwa, waɗannan ƙunƙulewa sune "masu laifi" waɗanda ke goge saman aikin. Magance ƙunƙulewa ƙalubale ne na duniya. Bayan ƙara ƙarin abubuwa da inganta tsarin yayin niƙawa, wata hanya mafi ƙarfi ita ce a gyara saman foda, a ba shi "rufi" don rage kuzarin saman da kuma hana shi ci gaba da son "rufewa".
Ⅲ. Damisa ta uku ita ce rashin tabbas da ke tattare da "ma'auni."
Ta yaya ka san cewa girman barbashi da ka sarrafa shi ne abin da kake tsammani? Masu nazarin girman barbashi su ne idanunmu, amma ƙa'idodin aunawa daban-daban (diffraction na laser, sedimentation, nazarin hoto), har ma da hanyoyin watsawa daban-daban na samfura a ƙarƙashin ƙa'ida ɗaya, na iya haifar da sakamako daban-daban. Wannan gaskiya ne musamman ga foda waɗanda suka riga sun haɗu; idan ba a cimma ingantaccen watsawa ba kafin a auna (misali, ƙara masu watsawa, maganin ultrasonic), bayanan da aka samu ba za su yi kama da ainihin yanayin ba. Ba tare da ingantaccen ma'auni ba, cikakken iko kawai magana ce ta banza.
Duk da waɗannan ƙalubalen, masana'antar tana ci gaba da neman mafita. Misali, tsaftacewa da wayo na dukkan tsarin babban ci gaba ne. Ta hanyar kayan aikin sa ido kan girman barbashi ta yanar gizo, ra'ayoyin bayanai na ainihin lokaci da daidaitawar ma'aunin niƙa da rarrabuwa ta atomatik suna haifar da tsari mai ƙarfi. Bugu da ƙari, fasahar gyaran saman tana samun ƙarin kulawa, ba ta sake zama "magani" ba bayan gaskiya, amma an haɗa ta cikin dukkan tsarin shiri, tana hana haɗuwa daga tushe da inganta wargajewar foda da kuma dacewa da tsarin aikace-aikacen. III. Kiran Aikace-aikace: Ta Yaya Girman Barbashi Ya Zama "Dutsen Masanin"?
Me yasa ake yin irin wannan ƙoƙari don sarrafa girman barbashi? Idan aka duba aikace-aikacen da ake amfani da su a aikace, hakan ya bayyana sarai. A fannin niƙa da gogewa daidai, kamar allon goge sapphire da wafers na silicon, rarraba girman barbashi na ƙaramin foda na silicon carbide mai launin kore "layin rayuwa ne." Yana buƙatar rarraba girman barbashi mai kunkuntar da iri ɗaya, ba tare da "bambancin barbashi masu yawa" ba (wanda kuma ake kira "bambancin barbashi" ko "bambancin barbashi masu kisa"), in ba haka ba, karce mai zurfi ɗaya na iya lalata dukkan kayan aikin da ke da tsada. A lokaci guda, foda ba dole bane ya sami agglomerates masu tauri, in ba haka ba ingancin gogewa zai yi ƙasa, kuma ƙarewar saman ba zai gamsar ba. A nan, ana kiyaye sarrafa girman barbashi sosai a sikelin nano.
A cikin kayan da suka fi ƙarfin juriya, kamar kayan daki na yumbu da kuma rufin tanderu mai zafi, sarrafa girman barbashi yana mai da hankali kan "rarraba girman barbashi." Barbashi masu kauri da ƙanana suna haɗuwa a wani rabo; barbashi masu kauri suna samar da tsarin, kuma ƙananan barbashi suna cike gibin. Wannan yana ba da damar yin sintering mai yawa da ƙarfi a yanayin zafi mai yawa, wanda ke haifar da juriya mai kyau ga girgizar zafi. Idan rarraba girman barbashi bai dace ba, kayan zai zama mai ramuka kuma ba zai dawwama ba, ko kuma ya yi rauni sosai kuma yana iya fashewa. A fannin tukwane na musamman, kamar tukwane masu hana harsashi da zoben rufewa masu jure lalacewa, girman barbashi na foda yana shafar tsarin microstructure kai tsaye da aikin ƙarshe bayan sintering. Foda mai laushi da iri ɗaya suna da babban aikin sintering, yana ba da damar samun ƙarin yawa da tukwane masu ƙanƙanta a ƙananan yanayin zafi, don haka yana inganta ƙarfi da tauri sosai. A nan, girman barbashi shine sirrin da ke tattare da "ƙarfafa" kayan yumbu.