Alumina foda nasara a cikin 3D bugu kayan
Tafiya cikin dakin gwaje-gwaje na Jami'ar Polytechnic ta Arewa maso Yamma, mai haske3D printer yana ɗan huɗa kaɗan, kuma katakon Laser yana tafiya daidai a cikin yumbura slurry. Bayan 'yan sa'o'i kadan bayan haka, an gabatar da babban yumbu mai mahimmanci kamar maze - za a yi amfani da shi don jefa turbine na injunan jirgin sama. Farfesa Su Haijun, wanda ke kula da aikin, ya yi nuni ga sassa masu laushi kuma ya ce: "Shekaru uku da suka wuce, ba mu kuskura mu yi tunanin irin wannan madaidaicin ba. Babban nasarar da aka samu yana ɓoye a cikin wannan foda na alumina da ba a sani ba."
Da zarar wani lokaci, alumina yumbura sun kasance kamar "dalibi mai matsala" a fagen3D bugu- ƙarfi mai ƙarfi, juriya mai zafi, haɓaka mai kyau, amma da zarar an buga shi, yana da matsaloli da yawa. A karkashin tsarin al'ada, alumina foda yana da rashin ruwa mara kyau kuma sau da yawa yana toshe shugaban buga; raguwar raguwa a lokacin sintiri zai iya kaiwa 15% -20%, kuma sassan da aka buga tare da ƙoƙari sosai za su lalace kuma su tsage da zarar an ƙone su; hadaddun tsarin? Har ma ya fi na alatu. Injiniyoyin sun damu: “Wannan abu kamar mai zane ne mai taurin kai, mai ra’ayin daji amma bai isa ba.”
1. Tsarin Rasha: Sanya "maganin yumbu" a kanaluminummatrix
Juyawar farko ta fito ne daga juyin juya hali a cikin ƙirar kayan aiki. A cikin 2020, masana kimiyyar kayan abu daga Jami'ar Kimiyya da Fasaha ta Kasa (NUST MISIS) ta Rasha sun ba da sanarwar fasahohin da ke dagula lamarin. Maimakon kawai haɗuwa da foda na aluminum oxide, sun sanya foda mai tsabta mai tsabta a cikin autoclave kuma sun yi amfani da hydrothermal oxidation don "girma" wani Layer na fim din aluminum oxide tare da daidaitaccen kauri mai sarrafawa a saman kowane nau'in aluminum, kamar sanya wani Layer na nano-matakin makamai a kan ƙwallon aluminum. Wannan "tsarin tsarin harsashi" foda yana nuna aikin ban mamaki a lokacin bugu na 3D na laser (fasaha na SLM): taurin shine 40% mafi girma fiye da na kayan aluminium mai tsabta, kuma kwanciyar hankali mai zafi yana inganta sosai, kai tsaye yana saduwa da bukatun jirgin sama.
Farfesa Alexander Gromov, shugaban aikin, ya yi kwatanci mai ma'ana: "A da, kayan haɗin gwiwar sun kasance kamar salatin - kowannensu yana kula da kasuwancinsa; fodanmu kamar sandwiches - aluminum da alumina suna cizon juna ta hanyar Layer, kuma ba zai iya yin ba tare da ɗayan ba." Wannan haɗin gwiwa mai ƙarfi yana ba da damar kayan don nuna ƙarfinsa a cikin sassan injin jirgin sama da firam ɗin jiki mai haske, har ma ya fara ƙalubalantar ƙasa na gami da titanium.
2. Hikimar kasar Sin: sihirin "saitin" yumbu
Babban abin jin zafi na bugu na yumbura na alumina shine raguwar raguwa - yi tunanin cewa kun cuku a hankali wani adadi na yumbu, kuma ya ragu zuwa girman dankalin turawa da zarar ya shiga cikin tanda. Nawa ne zai rushe? A farkon 2024, sakamakon da ƙungiyar Farfesa Su Haijun ta buga a Jami'ar Kimiyya da Fasaha ta Arewa maso Yamma a cikin Journal of Materials Science & Technology ya kashe masana'antar: sun sami kusan sifili-shrinkage alumina yumbu core tare da raguwar ƙimar 0.3% kawai.
Sirrin shine ƙarawaaluminum fodazuwa alumina sannan kuma kunna madaidaicin "sihiri yanayi".
Add aluminum foda: Mix 15% na kyau aluminum foda a cikin yumbu slurry
Sarrafa yanayi: Yi amfani da kariyar iskar argon a farkon sintering don hana aluminum foda daga oxidizing
Canjin wayo: Lokacin da zafin jiki ya tashi zuwa 1400C, ba zato ba tsammani canza yanayin zuwa iska
In-situ oxidation: Aluminum foda nan take narke cikin droplets kuma oxidizes zuwa aluminum oxide, da girma girma dillalan kwangila.
3. Juyin Juyin Halitta: Aluminum foda ya juya zuwa "manne marar ganuwa"
Yayin da ƙungiyoyin Rasha da na Sin suna aiki tuƙuru akan gyare-gyaren foda, wata hanyar fasaha ta balaga cikin nutsuwa - ta yin amfani da foda na aluminum a matsayin mai ɗaure. yumbu na gargajiya3D bugumasu ɗaure su ne galibin resins na halitta, waɗanda za su bar cavities lokacin da aka ƙone su a lokacin lalata. Tambarin ƙungiyar cikin gida ta 2023 tana ɗaukar wata hanya ta daban: yin foda na aluminium a cikin binder na tushen ruwa47.
A lokacin bugu, bututun ƙarfe yana fesa daidai "manne" mai ɗauke da 50-70% aluminium foda akan Layer oxide foda. Lokacin da ya zo mataki na ragewa, ana zana injin kuma ana wucewa ta oxygen, kuma foda na aluminum yana da oxidized zuwa aluminum oxide a 200-800 ° C. Halin haɓaka ƙarar ƙarar fiye da 20% yana ba shi damar cika pores na rayayye kuma ya rage ƙimar raguwa zuwa ƙasa da 5%. "Ya yi daidai da wargaza tarkace da gina sabon bango a lokaci guda, cike ramukan ku!" wani injiniya ya bayyana haka.
4. The art na barbashi: nasarar mai siffar zobe foda
"Bayyana" na alumina foda ya zama ba zato ba tsammani ya zama mabuɗin ga nasara - wannan bayyanar yana nufin siffar barbashi. Wani bincike a cikin mujallar "Open Ceramics" a cikin 2024 idan aka kwatanta da aikin alumina foda mai siffar zobe da na yau da kullun a cikin abin da aka haɗa (CF³) bugu5:
Spherical foda: yana gudana kamar yashi mai kyau, ƙimar cikawa ya wuce 60%, kuma bugu yana da santsi da siliki
Foda mara daidaituwa: makale kamar sukari mai laushi, danko ya ninka sau 40 mafi girma, kuma an toshe bututun don shakkar rayuwa.
Har ma mafi kyau, yawancin sassan da aka buga ta hanyar foda mai siffar zobe sauƙi ya wuce 89% bayan sintering, kuma ƙarshen saman ya dace da daidaitattun. "Wane ne har yanzu yana amfani da "mummunan" foda a yanzu? Fluidity shine tasirin yaki!" Wani technician yayi murmushi ya k'arashe5.
Gaba: Taurari da tekuna suna rayuwa tare da ƙanana da kyau
Juyin bugu na 3D na foda alumina bai ƙare ba. Masana'antar soji ta dauki gaba wajen yin amfani da ma'adinan da ke kusa-kusa da sifili don kera ruwan turbofan; Filin nazarin halittu ya ɗauki zato ga kwatancensa kuma ya fara buga na'urar dasa ƙashi na musamman; masana'antun lantarki sun yi niyya ga abubuwan da ke haifar da zafi - bayan haka, yanayin zafi da rashin wutar lantarki na alumina ba za a iya maye gurbinsu ba.