Muna amfani da kukis don inganta ƙwarewar ku.Ta ci gaba da bincika wannan rukunin yanar gizon, kun yarda da amfani da kukis.Ƙarin Bayani.
Ƙirƙirar ƙira (AM) ta ƙunshi ƙirƙirar abubuwa na 3D, Layer mai kauri ɗaya a lokaci guda, yana mai da shi tsada fiye da sarrafa kayan gargajiya.Duk da haka, kawai ƙaramin yanki na foda yana waldawa zuwa sashin yayin aikin haɗuwa.Sauran ba sa fuse, don haka za a iya sake amfani da su.Sabanin haka, idan an halicci abu ta hanyar gargajiya, yawanci yana buƙatar niƙa da injina don cire kayan.
Abubuwan da ke cikin foda suna ƙayyade sigogi na injin kuma dole ne a yi la'akari da su a farkon wuri.Kudin AM ba zai zama mai tattalin arziki ba saboda cewa foda da ba a narkewa ba ta gurɓace kuma ba za a iya sake yin amfani da ita ba.Rushewar foda yana haifar da al'amura guda biyu: gyare-gyaren sinadarai na samfurin da canje-canje a cikin kayan aikin injiniya kamar ilimin halittar jiki da rarraba girman barbashi.
A cikin akwati na farko, babban aikin shine ƙirƙirar ƙwararrun sifofi waɗanda ke ɗauke da tsattsauran allo, don haka muna buƙatar guje wa gurɓataccen foda, alal misali, tare da oxides ko nitrides.A cikin sabon abu na ƙarshe, waɗannan sigogi suna da alaƙa da ruwa da kuma yadawa.Sabili da haka, duk wani canji a cikin kaddarorin foda na iya haifar da rarrabawar samfuran da ba ta dace ba.
Bayanai daga wallafe-wallafen na baya-bayan nan sun nuna cewa na'urorin gargajiya na gargajiya ba za su iya samar da cikakkun bayanai game da rarraba foda a cikin AM bisa ga gadon foda.Game da halayen albarkatun kasa (ko foda), akwai hanyoyin aunawa da yawa masu dacewa akan kasuwa waɗanda zasu iya gamsar da wannan buƙatu.Yanayin damuwa da filin kwararar foda dole ne su kasance iri ɗaya a cikin saitin aunawa da kuma cikin tsari.Kasancewar abubuwan matsawa ba su dace ba tare da kwararar sararin samaniya kyauta da ake amfani da su a cikin na'urorin IM a cikin masu gwada ƙarfi da rheometer na gargajiya.
GranuTools ya haɓaka aikin aiki don siffanta foda AM.Babban burinmu shine samar da kowane nau'in lissafi tare da ingantaccen kayan aikin kwaikwayo na tsari, kuma ana amfani da wannan aikin don fahimta da bin diddigin haɓakar ingancin foda a cikin matakai daban-daban na bugu.An zaɓi madaidaitan allunan aluminum (AlSi10Mg) don lokuta daban-daban a nau'ikan zafi daban-daban (daga 100 zuwa 200 ° C).
Ana iya sarrafa lalatawar thermal ta hanyar nazarin ikon foda don tara cajin lantarki.An bincika foda don gudana (kayan GranuDrum), tattarawar motsin motsi (kayan GranuPack) da halayen lantarki (kayan aikin GranuCharge).Haɗin kai da ma'auni na kinetics na tattarawa sun dace don bin ingancin foda.
Foda da ke da sauƙin amfani za su nuna ƙananan alamar haɗin kai, yayin da foda tare da saurin cikawa da sauri za su samar da sassa na inji tare da ƙananan porosity idan aka kwatanta da mafi wuyar cika samfurori.
Bayan da yawa watanni na ajiya a cikin dakin gwaje-gwaje, uku aluminum gami powders tare da daban-daban barbashi size rarraba (AlSi10Mg) da kuma daya 316L bakin karfe samfurin aka zaba, a nan ake magana a kai a matsayin samfurori A, B da C. Abubuwan samfurori na iya bambanta da sauran masana'antun.An auna girman rarrabuwar samfurin ta hanyar nazarin diffraction laser/ISO 13320.
Saboda suna sarrafa ma'auni na na'ura, dole ne a fara la'akari da kaddarorin foda, kuma idan foda ba tare da narke ba ana la'akari da gurɓatacce kuma ba za a iya sake yin amfani da su ba, to masana'antun haɓaka ba su da tattalin arziki kamar yadda mutum zai iya fata.Sabili da haka, za a bincika sigogi guda uku: kwararar foda, haɓakar tattarawa da electrostatics.
Yadawa yana da alaƙa da daidaituwa da kuma "lalata" na foda Layer bayan aikin sake dawowa.Wannan yana da mahimmanci sosai saboda filaye masu santsi suna da sauƙin bugawa kuma ana iya bincika su tare da kayan aikin GranuDrum tare da ma'aunin ma'aunin mannewa.
Saboda pores sune maki masu rauni a cikin abu, zasu iya haifar da fashewa.Cika kuzari shine madaidaicin maɓalli na biyu kamar yadda saurin cika foda ke ba da ƙarancin porosity.Ana auna wannan hali tare da GranuPack tare da ƙimar n1/2.
Kasancewar cajin lantarki a cikin foda yana haifar da haɗin kai wanda ke haifar da samuwar agglomerates.GranuCharge yana auna ikon foda don samar da cajin lantarki lokacin da yake hulɗa da kayan da aka zaɓa yayin gudana.
Yayin aiki, GranuCharge na iya hasashen lalacewar kwarara, misali, lokacin ƙirƙirar Layer a cikin AM.Don haka, ma'aunin da aka samu yana da matukar damuwa ga yanayin ƙwayar hatsi (haɓaka, gurɓatawa da rashin ƙarfi).Za a iya ƙididdige tsufan foda da aka dawo da shi daidai (±0.5 nC).
GranuDrum tsari ne na ma'aunin ma'aunin foda wanda aka tsara bisa ka'idar ganga mai juyawa.Rabin samfurin foda yana ƙunshe a cikin silinda mai kwance tare da ganuwar gefen m.Drum ɗin yana jujjuya kusurwoyinsa a saurin kusurwa na 2 zuwa 60 rpm, kuma kyamarar CCD tana ɗaukar hotuna (daga hotuna 30 zuwa 100 a tazarar daƙiƙa 1).Ana gano ƙirar iska / foda akan kowane hoto ta amfani da algorithm gano gefen.
Yi ƙididdige matsakaicin matsakaicin matsakaicin ƙa'idar da kuma jujjuyawa a kusa da wannan matsakaicin matsayi.Ga kowane saurin juyi, kusurwar kwarara (ko “tsarin kusurwar hutawa”) αf ana ƙididdige shi daga madaidaicin madaidaicin wuri, kuma σf mai ƙarfi haɗin kai da ke hade da haɗin gwiwar intergrain ana nazarinsa daga jujjuyawar mu'amala.
Matsakaicin magudanar ruwa yana shafar ma'auni masu yawa: gogayya, siffa da haɗin kai tsakanin barbashi (van der Waals, electrostatic da capillary Forces).Ƙaƙƙarfan foda masu haɗaka suna haifar da raguwa mai tsaka-tsaki, yayin da foda mara kyau ya haifar da gudana na yau da kullum.Ƙananan dabi'u na kusurwar kwarara αf sun dace da kyakkyawan kwarara.Ma'anar mannewa mai ƙarfi kusa da sifili yayi daidai da foda mara daidaituwa, don haka yayin da mannewar foda ya karu, madaidaicin mannewa yana ƙaruwa daidai da haka.
GranuDrum yana ba ku damar auna kusurwar farko na avalanche da aeration na foda yayin gudana, da kuma auna ma'aunin mannewa σf da kusurwar kwarara αf dangane da saurin juyawa.
Girman girma na GranuPack, yawan taɓawa da ma'aunin rabo na Hausner (wanda kuma aka sani da "gwajin tapping") suna da kyau don halayyar foda saboda sauƙin su da saurin aunawa.Girman foda da ikon ƙara yawan adadinsa sune mahimman bayanai a lokacin ajiya, sufuri, agglomeration, da dai sauransu. An tsara hanyoyin da aka ba da shawarar a cikin Pharmacopoeia.
Wannan gwaji mai sauƙi yana da manyan lahani guda uku.Ma'auni ya dogara da mai aiki, kuma hanyar cikawa yana rinjayar ƙarar farko na foda.Auna jimlar ƙarar zai iya haifar da kurakurai masu tsanani a cikin sakamakon.Saboda sauƙi na gwajin, ba mu yi la'akari da ma'auni mai mahimmanci tsakanin ma'auni na farko da na ƙarshe ba.
An yi nazarin halayen foda da aka ciyar a cikin ci gaba da fitarwa ta amfani da kayan aiki na atomatik.Daidai auna ma'aunin Hausner coefficient Hr, ƙimar farko ρ(0) da ƙimar ƙarshe ρ(n) bayan n dannawa.
Yawan famfo yawanci yana daidaitawa a n=500.GranuPack wani ma'auni ne mai sarrafa kansa da ci-gaban ma'aunin taɓawa dangane da bincike mai ƙarfi na kwanan nan.
Ana iya amfani da wasu fihirisa, amma ba a bayar da su a nan ba.Ana sanya foda a cikin bututun ƙarfe ta hanyar ƙaƙƙarfan tsarin farawa mai sarrafa kansa.An cire madaidaicin siga mai ƙarfi n1/2 da matsakaicin girman ρ(∞) daga madaidaicin madaidaicin.
Silinda mara nauyi mai nauyi yana zaune a saman gadon foda don kiyaye matakin mu'amalar foda/ iska yayin dannewa.Bututun da ke dauke da samfurin foda ya tashi zuwa tsayin tsayin ΔZ kuma ya fadi da yardar kaina a tsayin da aka saba gyarawa a ΔZ = 1 mm ko ΔZ = 3 mm, wanda aka auna ta atomatik bayan kowane tabawa.Yi lissafin ƙarar V na tari daga tsayi.
Density shine ma'auni na ma'auni m zuwa ƙarar ƙwayar foda V. An san yawan adadin foda m, ana amfani da yawa ρ bayan kowane tasiri.
Hausner coefficient Hr yana da alaƙa da ma'auni mai mahimmanci kuma ana nazarin shi ta hanyar daidaitawa Hr = ρ (500) / ρ (0), inda ρ (0) shine farkon girma mai yawa kuma ρ (500) shine ƙididdigewa bayan 500 hawan keke.Matsa yawa.Lokacin amfani da hanyar GranuPack, ana iya samun sakamako ta amfani da ƙaramin foda (yawanci 35 ml).
Abubuwan da ke cikin foda da kaddarorin kayan da aka yi na'urar sune mahimman sigogi.A lokacin kwarara, ana haifar da cajin electrostatic a cikin foda saboda tasirin triboelectric, wanda shine musayar caji lokacin da daskararru biyu suka shiga cikin hulɗa.
Lokacin da foda ke gudana a cikin na'urar, tasirin triboelectric yana faruwa a lamba tsakanin barbashi da a lamba tsakanin barbashi da na'urar.
Bayan tuntuɓar kayan da aka zaɓa, GranuCharge ta atomatik yana auna adadin cajin lantarki da aka haifar a cikin foda yayin gudana.Samfurin foda yana gudana a cikin V-tube mai girgiza kuma ya faɗi cikin kofin Faraday da aka haɗa da na'urar lantarki wanda ke auna cajin da aka samu yayin da foda ke motsawa cikin V-tube.Don sakamako mai iya sakewa, yi amfani da na'urar juyawa ko girgiza don ciyar da bututun V akai-akai.
Sakamakon triboelectric yana haifar da wani abu ya sami electrons a samansa kuma ta haka ya zama mummunan caji, yayin da wani abu ya rasa electrons kuma ta haka ya zama mai cajin gaske.Wasu kayan suna samun electrons cikin sauƙi fiye da wasu, hakazalika, sauran kayan suna rasa electrons cikin sauƙi.
Wani abu ya zama mara kyau kuma wanda ya zama tabbatacce ya dogara da kusancin abubuwan da ke tattare da samun ko rasa electrons.Don wakiltar waɗannan halaye, an haɓaka jerin triboelectric da aka nuna a cikin Table 1.An jera kayan da ke da yanayin caji mai kyau da sauran waɗanda ke da yanayin caji mara kyau, kuma ana jera hanyoyin kayan da ba su nuna wani yanayin ɗabi'a a tsakiyar tebur ba.
A gefe guda, teburin kawai yana ba da bayanai kan abubuwan da ke faruwa a cikin halin caji na kayan, don haka an ƙirƙiri GranuCharge don samar da ingantattun ƙimar ƙima don halin caji na foda.
An gudanar da gwaje-gwaje da yawa don nazarin bazuwar zafi.An sanya samfurori a 200 ° C na sa'o'i daya zuwa biyu.Ana bincika foda nan da nan tare da GranuDrum (sunan zafi).An sanya foda a cikin akwati har sai ya kai ga yanayin zafi sannan a bincika ta amfani da GranuDrum, GranuPack da GranuCharge (watau "sanyi").
An yi nazarin samfurorin da aka yi amfani da su ta amfani da GranuPack, GranuDrum da GranuCharge a dakin zafi / yanayin zafi (watau 35.0 ± 1.5% RH da 21.0 ± 1.0 °C zafin jiki).
Ƙididdigar haɗin kai yana ƙididdige yawan gudana na foda kuma yana daidaitawa tare da canje-canje a cikin matsayi na dubawa (foda / iska), wanda shine kawai ƙungiyoyin sadarwa guda uku (van der Waals, capillary da electrostatic Forces).Kafin gwajin, an yi rikodin yanayin zafi na dangi (RH,%) da zazzabi (°C).Sa'an nan kuma aka zuba foda a cikin ganga, kuma an fara gwaji.
Mun kammala cewa waɗannan samfuran ba su da sauƙi ga haɓakawa yayin la'akari da sigogin thixotropic.Abin sha'awa shine, damuwa na thermal ya canza halayen rheological na foda na samfurori A da B daga girma mai girma zuwa raguwa mai laushi.A gefe guda kuma, Samfurori C da SS 316L ba su shafi yanayin zafi ba kuma sun nuna kauri kawai.Kowane foda yana da mafi kyawun yaduwa (watau ƙananan haɗin kai) bayan dumama da sanyaya.
Har ila yau, tasirin zafin jiki ya dogara da takamaiman yanki na barbashi.Mafi girman ma'auni na thermal conductivity na kayan, mafi girman tasiri akan zafin jiki (watau ???225°?=250??-1.?-1) da ???316?.225°?=19?Aluminum alloy foda suna da kyau don aikace-aikacen zafin jiki mai girma saboda haɓakar haɓakar su, har ma da sanyaya samfuran suna samun mafi kyawun kwarara fiye da foda na asali.
Ga kowane gwajin GranuPack, an rubuta adadin foda kafin kowane gwaji, kuma an buga samfurin sau 500 tare da tasirin tasirin 1 Hz tare da faɗuwar kyauta na 1 mm a cikin tantanin halitta (tasirin makamashi ∝).Ana rarraba samfurin a cikin tantanin aunawa bisa ga umarnin software mai zaman kansa.Sa'an nan kuma an maimaita ma'auni sau biyu don tantance sakewa da kuma bincika ma'anar ma'auni da ma'auni.
Bayan an kammala nazarin GranuPack, ƙimar girma na farko (ρ (0)), ƙarancin girma na ƙarshe (a yawancin taps, n = 500, watau ρ (500)), Hausner rabo / Carr index (Hr / Cr) da sigogin rajista guda biyu (n1/2 da τ) masu alaƙa da haɗin gwiwa.Hakanan ana nuna mafi kyawun ƙimar ρ(∞) (duba Shafi 1).Teburin da ke ƙasa yana sake tsara bayanan gwaji.
Figures 6 da 7 suna nuna jimlar haɗaɗɗiyar lanƙwasa (yawan yawa tare da adadin tasirin) da ma'aunin n1/2/Hausner.Ana nuna sandunan kurakurai da aka ƙididdige su ta amfani da ma'ana akan kowane lanƙwasa, kuma an ƙididdige madaidaicin sabani ta gwajin maimaitawa.
Samfurin bakin karfe na 316L shine samfurin mafi nauyi (ρ(0) = 4.554 g/mL).Dangane da yawan matsi, SS 316L ya kasance foda mafi nauyi (ρ (n) = 5.044 g/mL), sannan Samfurin A (ρ (n) = 1.668 g/mL), sannan Sample B (ρ (n) = 1.668 g/ml)./ml) (n) = 1.645 g/ml).Samfurin C shine mafi ƙanƙanta (ρ(n) = 1.581 g/mL).Dangane da girman girman foda na farko, mun ga cewa samfurin A shine mafi sauƙi, kuma la'akari da kurakurai (1.380 g / ml), samfuran B da C suna da kusan ƙimar ɗaya.
Yayin da foda ke zafi, rabonsa na Hausner yana raguwa, kuma wannan yana faruwa ne kawai tare da samfurori B, C, da SS 316L.Don samfurin A, ba zai yiwu a yi ba saboda girman sandunan kuskure.Don n1/2, yanayin jujjuyawar juzu'i ya fi rikitarwa.Don samfurin A da SS 316L, ƙimar n1 / 2 ya ragu bayan 2 h a 200 ° C, yayin da foda B da C ya karu bayan hawan thermal.
Anyi amfani da feeder mai girgiza don kowane gwajin GranuCharge (duba Hoto 8).Yi amfani da bututun bakin karfe 316L.An maimaita ma'auni sau 3 don tantance sake haifuwa.Nauyin samfurin da aka yi amfani da shi don kowane ma'auni ya kusan 40 ml kuma babu foda da aka dawo bayan aunawa.
Kafin gwajin, an yi rikodin nauyin foda (mp, g), yanayin zafi na dangi (RH,%), da zafin jiki (°C).A farkon gwajin, an auna yawan cajin foda na farko (q0 a cikin µC/kg) ta sanya foda a cikin kofin Faraday.A ƙarshe, an saita adadin foda kuma an ƙididdige ƙimar ƙimar ƙarshe (qf, µC / kg) da Δq (Δq = qf - q0) a ƙarshen gwajin.
Ana nuna danyen bayanan GranuCharge a cikin Tebura 2 da Hoto 9 (σ shine daidaitattun ƙididdiga da aka ƙididdige su daga sakamakon gwajin maimaitawa), kuma ana nuna sakamakon azaman histogram (q0 da Δq kawai aka nuna).SS 316L yana da mafi ƙarancin cajin farko;wannan na iya zama saboda gaskiyar cewa wannan samfurin yana da mafi girman PSD.Lokacin da ya zo na farko loading na primary aluminum gami foda, ba za a iya zana karshe saboda girman da kurakurai.
Bayan tuntuɓar bututun bakin karfe na 316L, samfurin A ya karɓi mafi ƙarancin cajin, yayin da powders B da C sun nuna irin wannan yanayin, idan an goge foda SS 316L akan SS 316L, an sami ƙarancin caji kusa da 0 (duba jerin triboelectric) .Samfurin B har yanzu yana da caji fiye da A. Don samfurin C, yanayin yana ci gaba (tabbatacciyar cajin farko da cajin ƙarshe bayan yayyo), amma adadin cajin yana ƙaruwa bayan lalatawar thermal.
Bayan sa'o'i 2 na damuwa na thermal a 200 ° C, halin foda ya zama mai ban sha'awa sosai.A cikin samfuran A da B, cajin farko ya ragu kuma cajin ƙarshe ya canza daga korau zuwa tabbatacce.SS 316L foda yana da mafi girman cajin farko kuma canjin ƙimarsa ya zama tabbatacce amma ya kasance ƙasa (watau 0.033 nC/g).
Mun bincika sakamakon lalacewar thermal akan halayen haɗin gwiwar aluminum gami (AlSi10Mg) da 316L bakin karfe foda, yayin da aka bincika foda na asali bayan sa'o'i 2 a 200 ° C a cikin iska.
Yin amfani da foda a yanayin zafi mai girma zai iya inganta haɓakar samfurin, sakamakon da ya bayyana ya zama mafi mahimmanci ga foda tare da babban yanki mai mahimmanci da kayan aiki tare da haɓakaccen zafi.An yi amfani da GranuDrum don kimanta kwararar ruwa, an yi amfani da GranuPack don nazarin tattara kaya mai ƙarfi, kuma an yi amfani da GranuCharge don nazarin triboelectricity na foda a cikin hulɗa da bututun bakin karfe na 316L.
An ƙaddara waɗannan sakamakon ta amfani da GranuPack, wanda ya nuna haɓakawa a cikin haɗin gwiwar Hausner ga kowane foda (ban da samfurin A, saboda girman kurakurai) bayan tsarin damuwa na thermal.Ba a sami wani yanayi mai ma'ana ba don ma'aunin tattarawa (n1/2) kamar yadda wasu samfuran ke nuna haɓakar saurin tattarawa yayin da wasu ke da tasiri mai ban sha'awa (misali Samfuran B da C).