Sisebenzisa amakhukhi ukuthuthukisa ulwazi lwakho. Ngokuqhubeka uphequlula le sayithi, uyavuma ukusebenzisa kwethu amakhukhi. Ulwazi Olwengeziwe.
Ukukhiqiza okungeziwe (i-AM) kuhilela ukudala izinto ze-3D, ungqimba olulodwa oluncane kakhulu ngesikhathi, okwenza kubize kakhulu kunokucubungula okuvamile. Kodwa-ke, ingxenye encane kuphela yempuphu ehlanganiswa nengxenye ngesikhathi senqubo yokuhlanganisa. Okunye akuhlanganisi, ngakho-ke kungasetshenziswa kabusha. Ngokuphambene nalokho, uma into idalwe ngendlela yakudala, ngokuvamile idinga ukugaya nokugaya ukuze kususwe izinto.
Izakhiwo zempuphu zinquma imingcele yomshini futhi kumele zicatshangelwe kwasekuqaleni. Izindleko ze-AM ngeke zibe zezongayonga uma kubhekwa ukuthi impuphu engancibilikisiwe ingcolile futhi ayikwazi ukuphinda isetshenziswe. Ukuwohloka kwempuphu kuholela ezimweni ezimbili: ukuguqulwa kwamakhemikhali komkhiqizo kanye nezinguquko ezimpahleni zemishini ezifana nokwakheka kanye nokusatshalaliswa kosayizi wezinhlayiya.
Esimweni sokuqala, umsebenzi oyinhloko ukudala izakhiwo eziqinile eziqukethe ama-alloy ahlanzekile, ngakho-ke sidinga ukugwema ukungcoliswa kwempuphu, isibonelo, ngama-oxide noma ama-nitride. Esimweni sokugcina, lawa mapharamitha ahlotshaniswa nokugeleza kanye nokusabalala. Ngakho-ke, noma yiluphi ushintsho ezimpahleni zempuphu lungaholela ekusakazweni komkhiqizo okungafani.
Idatha evela ezincwadini zakamuva ikhombisa ukuthi ama-flowmeter akudala awakwazi ukunikeza ulwazi olwanele mayelana nokusatshalaliswa kwempuphu ku-AM ngokusekelwe embhedeni wempuphu. Ngokuphathelene nokuhlukaniswa kwezinto zokusetshenziswa (noma impuphu), kunezindlela eziningana zokulinganisa ezifanele emakethe ezingahlangabezana nale mfuneko. Isimo sokucindezeleka kanye nensimu yokugeleza kwempuphu kumele kube okufanayo ekusethweni kokulinganisa kanye nasenqubweni. Ukuba khona kwemithwalo yokucindezela akuhambisani nokugeleza kobuso okukhululekile okusetshenziswa kumadivayisi e-IM kubahloli be-shear kanye nama-rheometer akudala.
I-GranuTools ithuthukise uhlelo lokusebenza lokuchaza i-AM powder. Umgomo wethu oyinhloko ukuhlomisa i-geometry ngayinye ngethuluzi lokulingisa inqubo elinembile, futhi lolu hlelo lokusebenza lusetshenziselwa ukuqonda nokulandelela ukuvela kwekhwalithi ye-powder ezinqubweni ezahlukene zokuphrinta. Kukhethwe ama-alloy amaningana e-aluminium ajwayelekile (i-AlSi10Mg) ngezikhathi ezahlukene emithwalweni ehlukene yokushisa (kusukela ku-100 kuya ku-200 °C).
Ukuwohloka kokushisa kungalawulwa ngokuhlaziya ikhono lempuphu lokuqongelela ishaja kagesi. Amampuphu ahlaziywe ukuze kutholakale ukugeleza (ithuluzi le-GranuDrum), i-kinetics yokupakisha (ithuluzi le-GranuPack) kanye nokuziphatha kwe-electrostatic (ithuluzi le-GranuCharge). Ukulinganisa i-cohesion kanye ne-kinetics yokupakisha kufanelekile ekulandeleleni ikhwalithi yempuphu.
Ama-powder okulula ukuwasebenzisa azobonisa izinkomba zokuhlangana okuphansi, kuyilapho ama-powder ane-fast filling dynamics azokhiqiza izingxenye zemishini ezine-porosity ephansi uma kuqhathaniswa nemikhiqizo enzima kakhulu ukuyigcwalisa.
Ngemva kwezinyanga eziningana zokugcina elabhorethri yethu, kwakhethwa izimpushana ezintathu ze-aluminium alloy ezinokusatshalaliswa kosayizi wezinhlayiya ezahlukene (i-AlSi10Mg) kanye nesampula eyodwa yensimbi engagqwali engu-316L, lapha okubhekiselwa kuzo njengamasampula A, B kanye no-C. Izakhiwo zamasampula zingahluka kwezabanye abakhiqizi. Ukusatshalaliswa kosayizi wezinhlayiya zesampula kwalinganiswa ngokuhlaziywa kwe-laser diffraction/ISO 13320.
Ngenxa yokuthi zilawula amapharamitha omshini, izakhiwo zempuphu kumele zicatshangelwe kuqala, futhi uma ama-powder angancibilikisiwe ebhekwa njengangcolile futhi angaphinde asetshenziswe, khona-ke ukukhiqizwa kwezengezo akubizi kakhulu njengoba umuntu engase alindele. Ngakho-ke, kuzohlolwa amapharamitha amathathu: ukugeleza kwempuphu, amandla okupakisha kanye nama-electrostatics.
Ukusabalala kuhlobene nokufana kanye "nobushelelezi" bengqimba yempuphu ngemva kokusebenza kokuphinda kufakwe. Lokhu kubaluleke kakhulu njengoba izindawo ezibushelelezi kulula ukuziphrinta futhi zingahlolwa ngethuluzi le-GranuDrum ngokulinganisa inkomba yokunamathela.
Ngenxa yokuthi ama-pores ayizindawo ezibuthakathaka ezintweni, angaholela ekuqhekekeni. I-Fill dynamics iyipharamitha yesibili ebalulekile njengoba ama-fast filling powders enikeza ama-porosity aphansi. Lokhu kuziphatha kulinganiswa nge-GranuPack enenani elingu-n1/2.
Ukuba khona kwamacala kagesi ku-powder kudala amandla ahlangene aholela ekwakhekeni kwama-agglomerate. I-GranuCharge ilinganisa ikhono lama-powder lokukhiqiza i-electrostatic charge lapho ixhumana nezinto ezikhethiwe ngesikhathi sokugeleza.
Ngesikhathi sokucubungula, i-GranuCharge ingabikezela ukuwohloka kokugeleza, isibonelo, lapho kwakha ungqimba ku-AM. Ngakho-ke, izilinganiso ezitholiwe zizwela kakhulu esimweni sobuso bezinhlamvu (ukubola, ukungcola kanye nokuqina). Ukuguga kwempuphu etholiwe kungalinganiswa ngokunembile (±0.5 nC).
I-GranuDrum iyindlela yokulinganisa ukugeleza kwempuphu ehleliwe esekelwe kusimiso sesigubhu esijikelezayo. Ingxenye yesampula yempuphu iqukethwe kusilinda esivundlile esinezindonga eziseceleni ezisobala. Isigubhu sijikeleza i-axis yaso ngesivinini se-angle esingu-2 kuya ku-60 rpm, kanti ikhamera ye-CCD ithatha izithombe (kusukela ezithombeni ezingu-30 kuya ku-100 ngezikhawu zesekhondi eli-1). Isixhumi somoya/impuphu sibonakala esithombeni ngasinye kusetshenziswa i-algorithm yokuthola unqenqema.
Bala indawo emaphakathi yesixhumi esibonakalayo kanye nokunyakaza okuzungeze lesi sikhundla esimaphakathi. Ngejubane ngalinye lokujikeleza, i-engeli yokugeleza (noma "i-engeli eguquguqukayo yokuphumula") i-αf ibalwa kusukela endaweni yesixhumi esimaphakathi, kanti i-dynamic cohesion factor σf ehlotshaniswa nokubopha kwe-intergrain ihlaziywa kusukela ekushintsheni kwesixhumi esibonakalayo.
I-engeli yokugeleza ithintwa yimingcele eminingana: ukungqubuzana, ukuma kanye nokuhlangana phakathi kwezinhlayiya (i-van der Waals, amandla kagesi kanye nama-capillary). Izimpushana ezihambisanayo zibangela ukugeleza okungenazikhawu, kuyilapho izimpushana ezingezona eziqinile zibangela ukugeleza okuvamile. Amanani aphansi e-engeli yokugeleza i-αf ahambisana nokugeleza okuhle. Inkomba yokunamathela enamandla eseduze no-zero ihambisana nempushana engavumelani, ngakho-ke njengoba ukunamathela kwempushana kukhuphuka, inkomba yokunamathela iyanda ngokufanele.
I-GranuDrum ikuvumela ukuthi ulinganise i-engeli yokuqala ye-avalanche kanye nomoya wempuphu ngesikhathi sokugeleza, kanye nokukala inkomba yokunamathela σf kanye ne-engeli yokugeleza αf kuye ngesivinini sokujikeleza.
Ubukhulu be-bulk density, ukuxinana kokuthepha kanye nezilinganiso ze-Hausner (ezaziwa nangokuthi “ukuhlolwa kokuthepha”) zilungele ukuhlukaniswa kwempuphu ngenxa yobulula bazo kanye nesivinini sokukala. Ubukhulu bempuphu kanye nekhono lokukhulisa ukuxinana kwayo kuyimingcele ebalulekile ngesikhathi sokugcina, ukuthuthwa, ukuhlanganiswa, njll. Izinqubo ezinconywayo zichazwe ku-Pharmacopoeia.
Lokhu kuhlolwa okulula kunezinkinga ezintathu ezinkulu. Ukulinganisa kuncike kumqhubi, futhi indlela yokugcwalisa ithinta ivolumu yokuqala yempuphu. Ukulinganisa ivolumu iyonke kungaholela emaphutheni amakhulu emiphumeleni. Ngenxa yobulula bokuhlola, asizange sicabangele ukuguquguquka kokuminyana phakathi kokulinganisa kokuqala nokokugcina.
Ukuziphatha kwempuphu efakwa endaweni yokukhipha eqhubekayo kuhlaziywe kusetshenziswa imishini ezenzakalelayo. Kala ngokunembile i-Hausner coefficient Hr, i-initial density ρ(0) kanye ne-final density ρ(n) ngemva kokuchofoza kuka-n.
Inani lamathephu livame ukunqunywa ku-n=500. I-GranuPack iyisilinganiso sobuningi bokuthinta esizenzakalelayo nesithuthukisiwe esisekelwe ocwaningweni lwamuva oluguquguqukayo.
Ezinye izinkomba zingasetshenziswa, kodwa azinikezwa lapha. Impuphu ifakwa epayipini lensimbi ngenqubo yokuqalisa ezenzakalelayo eqinile. Ukwengezwa kwepharamitha eguquguqukayo n1/2 kanye nobuningi obukhulu ρ(∞) kususiwe ku-compaction curve.
Isilinda esingenalutho esilula sihlala phezu kombhede wempuphu ukugcina izinga lokuxhumana kwempuphu/komoya ngesikhathi sokuqiniswa. Ithubhu equkethe isampula yempuphu ikhuphukela ekuphakameni okuhleliwe ΔZ futhi iwela ngokukhululeka ekuphakameni okuvame ukuqiniswa ku-ΔZ = 1 mm noma ΔZ = 3 mm, okulinganiswa ngokuzenzakalelayo ngemva kokuthinta ngakunye. Bala ivolumu V yenqwaba kusukela ekuphakameni.
Ubuningi buyisilinganiso sesisindo m kuya kuvolumu yesendlalelo sempuphu V. Isisindo sempuphu m siyaziwa, ubuningi ρ busetshenziswa ngemva kokushaya ngakunye.
I-Hausner coefficient Hr ihlobene ne-compaction factor futhi ihlaziywa nge-equation Hr = ρ(500) / ρ(0), lapho i-ρ(0) iyi-bulk density yokuqala kanye ne-ρ(500) iyi-flow ebaliwe ngemva kwemijikelezo engu-500. I-Density tap. Uma usebenzisa indlela ye-GranuPack, imiphumela ingaphinde ikhiqizwe kusetshenziswa inani elincane le-powder (ngokuvamile i-35 ml).
Izakhiwo zempuphu kanye nezakhiwo zezinto ezenziwe ngazo idivayisi ziyimingcele ebalulekile. Ngesikhathi sokugeleza, amashaja kagesi akhiqizwa ngaphakathi kwempuphu ngenxa yomphumela we-triboelectric, okuwukushintshana kwamacala lapho izinto ezimbili eziqinile zithintana.
Uma impuphu igeleza ngaphakathi kwedivayisi, kwenzeka umphumela we-triboelectric ekuthintaneni phakathi kwezinhlayiya kanye nasekuthintaneni phakathi kwezinhlayiya nedivayisi.
Uma ithintana nezinto ezikhethiwe, i-GranuCharge ilinganisa ngokuzenzakalelayo inani leshaja kagesi elikhiqizwa ngaphakathi kwempuphu ngesikhathi sokugeleza. Isampula yempuphu igeleza ngaphakathi kwe-V-tube edlidlizayo bese iwela enkomishini ye-Faraday exhunywe ku-electrometer elinganisa ishaja etholwe njengoba impuphu ihamba ngaphakathi kwe-V-tube. Ukuze uthole imiphumela ephindaphindwayo, sebenzisa idivayisi ejikelezayo noma edlidlizayo ukuze unikeze ama-V-tube njalo.
Umphumela we-triboelectric ubangela ukuthi into eyodwa ithole ama-electron ebusweni bayo bese ishajwa kabi, kuyilapho enye into ilahlekelwa ama-electron bese ishajwa kahle. Ezinye izinto zithola ama-electron kalula kunezinye, futhi ngokufanayo, ezinye izinto zilahlekelwa ama-electron kalula.
Ukuthi yiziphi izinto eziba zimbi nokuthi yiziphi eziba zimbi kuncike ekutheni izinto ezihilelekile zingakanani ukuze zithole noma zilahlekelwe ama-electron. Ukuze kumelelwe lezi zindlela, kwakhiwe uchungechunge lwe-triboelectric oluboniswe kuThebula 1. Izinto ezinendlela yokushaja enhle kanye nezinye ezinendlela yokushaja embi zibhaliwe, kanti izindlela zezinto ezingabonisi noma yiluphi uhlobo lokuthambekela kokuziphatha zibhalwe phakathi kwethebula.
Ngakolunye uhlangothi, ithebula linikeza ulwazi kuphela ngezitayela zokuziphatha kokushaja kwezinto, ngakho-ke i-GranuCharge yadalelwa ukuhlinzeka ngamanani anembile ezinombolo zokuziphatha kokushaja kwama-powder.
Kwenziwe izivivinyo eziningana ukuze kuhlaziywe ukubola kokushisa. Amasampula abekwa ku-200°C ihora elilodwa kuya kwamabili. Impushana ihlaziywa ngokushesha nge-GranuDrum (igama elishisayo). Impushana yabe isifakwa esitsheni ize ifinyelele izinga lokushisa elijwayelekile bese ihlaziywa kusetshenziswa i-GranuDrum, i-GranuPack kanye ne-GranuCharge (okungukuthi “ibanda”).
Amasampula angavuthiwe ahlaziywe kusetshenziswa i-GranuPack, i-GranuDrum kanye ne-GranuCharge endaweni efanayo yomswakama/izinga lokushisa (okungukuthi 35.0 ± 1.5% RH kanye no-21.0 ± 1.0 °C lokushisa).
Inkomba yokuhlangana ibala ukugeleza kwama-powder futhi ihlobene nezinguquko endaweni ye-interface (impuphu/umoya), okungamandla amathathu okuxhumana kuphela (i-van der Waals, amandla e-capillary kanye ne-electrostatic). Ngaphambi kokuhlolwa, umswakama womoya ohlobene (RH, %) kanye nokushisa (°C) kwaqoshwa. Ngemuva kwalokho i-powder yathululelwa esigubhini, kwaqala ukuhlolwa.
Siphethe ngokuthi le mikhiqizo ayithinteki ekuhlanganisweni kwe-agglomeration uma sicabangela imingcele ye-thixotropic. Ngokuthakazelisayo, ukucindezeleka kokushisa kushintshe ukuziphatha kwe-rheological kwama-powder amasampula A no-B kusukela ekuqineni kwe-shear kuya ekuncipheni kwe-shear. Ngakolunye uhlangothi, amaSamples C no-SS 316L awazange athintwe yizinga lokushisa futhi abonise kuphela ukujiya kwe-shear. I-powder ngayinye yayinokusabalala okungcono (okungukuthi i-cohesion index ephansi) ngemva kokushisa nokupholisa.
Umphumela wokushisa uncike endaweni ethile yezinhlayiya. Uma ukufudumala kwezinto kuphakeme, kulapho umphumela uba mkhulu khona ekushiseni (okungukuthi ???225°?=250?.?-1.?-1) kanye no ???316?. 225°?=19?.?-1.?-1) Uma izinhlayiya zincane, umphumela wokushisa uba mkhulu. Izimpushana ze-aluminium alloy zinhle kakhulu ekusetshenzisweni kwezinga lokushisa eliphezulu ngenxa yokusabalala kwazo okukhulu, futhi ngisho nezibonelo ezipholile zithola ukugeleza okungcono kunezimpushana zokuqala.
Kuvivinyo ngalunye lwe-GranuPack, isisindo sempuphu saqoshwa ngaphambi kokuhlolwa ngakunye, futhi isampula yashaywa izikhathi ezingu-500 ngemvamisa yomthelela engu-1 Hz kanye nokuwa kwamahhala okungu-1 mm kuseli lokulinganisa (amandla omthelela ∝). Isampula isatshalaliswa kuseli lokulinganisa ngokwemiyalelo yesofthiwe engasebenzisi umsebenzisi. Ngemuva kwalokho izilinganiso zaphindwa kabili ukuhlola ukuphindaphinda futhi kwaphenywa ukuphambuka okumaphakathi nokujwayelekile.
Ngemva kokuthi ukuhlaziywa kwe-GranuPack sekuqediwe, ubuningi bokuqala be-bulk (ρ(0)), ubuningi bokugcina be-bulk (kuma-taps amaningi, n = 500, okungukuthi ρ(500)), isilinganiso se-Hausner/Carr (Hr/Cr) kanye namapharamitha amabili okubhalisa (n1/2 kanye ne-τ) ahlobene ne-compaction kinetics. Ubuningi obuhle kakhulu ρ(∞) buyaboniswa futhi (bheka i-Appendix 1). Ithebula elingezansi lihlela kabusha idatha yokuhlola.
Izibalo 6 no-7 zibonisa ijika lokuxinana eliphelele (ubuningi obukhulu uma kuqhathaniswa nenani lemithelela) kanye nesilinganiso sepharamitha ye-n1/2/Hausner. Amabha amaphutha abalwe kusetshenziswa isilinganiso aboniswa kujika ngalinye, kanti ukuphambuka okujwayelekile kubalwe ngokuhlolwa kokuphindaphinda.
Umkhiqizo wensimbi engagqwali engu-316L wawungumkhiqizo osindayo kakhulu (ρ(0) = 4.554 g/mL). Ngokuphathelene nokuxinana kwe-tapping, i-SS 316L isalokhu iyimpuphu esindayo kakhulu (ρ(n) = 5.044 g/mL), ilandelwe yiSample A (ρ(n) = 1.668 g/mL), ilandelwe yiSample B (ρ(n) = 1.668 g/ml). /ml) (n) = 1.645 g/ml). Isampula C yayiphansi kakhulu (ρ(n) = 1.581 g/mL). Ngokusho kobuningi bempuphu yokuqala, sibona ukuthi isampula A iyona elula kakhulu, futhi uma sicabangela amaphutha (1.380 g / ml), amasampula B no-C anenani elifanayo.
Njengoba i-powder ishiswa, isilinganiso sayo se-Hausner siyancipha, futhi lokhu kwenzeka kuphela ngamasampula B, C, kanye ne-SS 316L. Kusampula A, bekungenakwenzeka ukusebenza ngenxa yobukhulu bemigqa yamaphutha. Ku-n1/2, ukugqama kwe-parametric trend kuyinkimbinkimbi kakhulu. Kusampula A kanye ne-SS 316L, inani le-n1/2 lehle ngemva kwamahora ama-2 ku-200°C, kuyilapho kuma-powder B kanye ne-C lenyuka ngemva kokulayisha ukushisa.
Kusetshenziswe i-feeder edlidlizayo ekuhlolweni ngakunye kwe-GranuCharge (bheka Umfanekiso 8). Sebenzisa ipayipi lensimbi engagqwali elingu-316L. Ukulinganisa kuphindwe kathathu ukuhlola ukuphindeka. Isisindo somkhiqizo osetshenziswe ekulinganisweni ngakunye sasicishe sibe ngu-40 ml futhi akukho mpuphu etholakele ngemva kokulinganisa.
Ngaphambi kokuhlolwa, isisindo sempuphu (mp, g), umswakama womoya ohlobene (RH, %), kanye nokushisa (°C) kwaqoshwa. Ekuqaleni kokuhlolwa, ubuningi beshaja yempuphu eyinhloko (q0 ku-µC/kg) balinganiswa ngokubeka impuphu endebeni yeFaraday. Ekugcineni, isisindo sempuphu salungiswa kwathi ubuningi beshaja yokugcina (qf, µC/kg) kanye ne-Δq (Δq = qf – q0) ekupheleni kokuhlolwa kwabalwa.
Idatha ye-GranuCharge eluhlaza iboniswe kuThebula 2 kanye noMfanekiso 9 (σ ukuphambuka okujwayelekile okubalwe kusukela emiphumeleni yokuhlolwa kokuphinda kukhiqizwe), futhi imiphumela iboniswa njenge-histogram (kuboniswa kuphela i-q0 kanye ne-Δq). I-SS 316L ineshaja yokuqala ephansi kakhulu; lokhu kungenzeka ngenxa yokuthi lo mkhiqizo une-PSD ephezulu kakhulu. Uma kukhulunywa ngokulayisha kokuqala kwempuphu ye-aluminium alloy eyinhloko, azikho iziphetho ezingathathwa ngenxa yobukhulu bamaphutha.
Ngemva kokuthintana nepayipi lensimbi engagqwali elingu-316L, isampula A ithole inani elincane kakhulu lokushaja, kuyilapho u-powder B no-C bebonisa ukuthambekela okufanayo, uma u-powder we-SS 316L uhlikihlwe ku-SS 316L, kutholakale ubuningi beshaja obuseduze no-0 (bheka uchungechunge lwe-triboelectric). Umkhiqizo B usashaja kakhulu kuno-A. Kusampula C, ukuthambekela kuyaqhubeka (ishaja yokuqala enhle kanye neshaja yokugcina ngemva kokuvuza), kodwa inani lamacala liyakhula ngemva kokuwohloka kokushisa.
Ngemva kwamahora ama-2 okucindezeleka kokushisa ku-200 °C, ukuziphatha kwempuphu kuba mnandi kakhulu. Kumasampula A no-B, ishaja yokuqala yehla futhi ishaja yokugcina yashintsha isuka ku-negative yaya ku-positive. Impuphu ye-SS 316L yayineshaja yokuqala ephezulu kakhulu futhi ushintsho lwayo lobuningi beshaja lwaba luhle kodwa yahlala iphansi (okungukuthi 0.033 nC/g).
Siphenye umphumela wokuwohloka kokushisa ekuziphatheni okuhlangene kwe-aluminium alloy (AlSi10Mg) kanye ne-316L stainless steel powders, kuyilapho i-powders yokuqala ihlaziywe ngemva kwamahora ama-2 ku-200°C emoyeni.
Ukusetshenziswa kwama-powder emazingeni okushisa aphezulu kungathuthukisa ukugeleza komkhiqizo, umphumela obonakala ubaluleke kakhulu kuma-powder anendawo ethile ephezulu nezinto ezisebenzisa ukushisa okuphezulu. I-GranuDrum yasetshenziswa ukuhlola ukugeleza, i-GranuPack yasetshenziswa ekuhlaziyeni ukupakisha okunamandla, kanti i-GranuCharge yasetshenziswa ukuhlaziya ugesi we-triboelectricity we-powder ethintana nepayipi lensimbi engagqwali elingu-316L.
Le miphumela inqunywe kusetshenziswa i-GranuPack, ebonise ukuthuthuka ku-Hausner coefficient yempuphu ngayinye (ngaphandle kwesampula A, ngenxa yobukhulu bamaphutha) ngemuva kwenqubo yokucindezeleka kokushisa. Akukho mkhuba ocacile otholiwe wepharamitha yokupakisha (n1/2) njengoba eminye imikhiqizo ibonise ukwanda kwesivinini sokupakisha kanti eminye inomphumela ohlukile (isb. Amasampula B no-C).