Iyakar Siffofi a cikin Karkashin Laser Sintering na Alumina

Jerin Abubuwan Ciki

• 1. Gabatarwa
• 2. Kayan Aiki da Hanyoyi
  • 2.1 Kayan Aiki
  • 2.2 Hanyoyi: Na'urar SLS da Sigogi
• 3. Sakamako da Tattaunawa
• 4. Cikakkun Bayanai na Fasaha da Tsarin Lissafi
• 5. Sakamakon Gwaji da Bayanin Ginshiƙi
• 6. Tsarin Bincike: Nazarin Lamari Ba tare da Lamba ba
• 7. Hangar Aikace-aikace da Hanyoyin Gaba
• 8. Nassoshi
• 9. Bincike na Asali & Sharhin Kwararru

1. Gabatarwa

Wannan binciken yana bincika iyakokin zane na siffofi don kera yumbun alumina tare da rikitattun buɗaɗɗen tashoshi ta amfani da Karkashin Zaɓaɓɓen Laser Sintering (SLS). Duk da cewa irin waɗannan gine-ginen suna da mahimmanci ga aikace-aikacen makamashi mai tsabta kamar na'urorin kwarara da kayan aikin haɓakawa, babu cikakkun dokokin zane. Manufar binciken ita ce: 1) gwada amfani da iyakokin siffofi da aka haɓaka don SLS na polymer zuwa karkashin SLS na yumbu, da kuma 2) gano da kuma tsara sabbin iyakoki, na musamman ga kayan da ke tasowa a cikin jerin ayyukan ƙara yumbu.

Karkashin SLS ya bambanta da hanyoyin kai tsaye ta yin amfani da mai ɗaurin polymer da aka sadaukar (misali, nylon PA12) da aka haɗa da foda na yumbu (misali, alumina). Laser yana haɗa mai ɗaurin don samar da wani "kore" na sashi, wanda daga baya ya sha rauni da kuma haɗawa (ƙarfafawa) a cikin aikin bayan gini. Wannan yana gabatar da ƙalubale na musamman waɗanda ba su wanzu a cikin SLS na polymer ba.

2. Kayan Aiki da Hanyoyi

2.1 Kayan Aiki

Kayan abinci sun kasance cakuda busasshe na 78 wt.% foda na alumina mai laushi (Almatis A16 SG, d50=0.3µm) da 22 wt.% nylon-12 (PA12, d50=58µm). An daidaita cakuda a cikin na'urar haɗawa mai ƙarfi na mintuna 10 kuma an tace ta ta hanyar raga na 250 µm. Siffar foda da aka samu, mai mahimmanci don yin kwarara da ajiya, an nuna ta a cikin zane da kuma a ƙarƙashin na'urar gani a cikin Hotuna na 2 da 3 na takarda.

2.2 Hanyoyi: Na'urar SLS da Sigogi

An yi ginin a kan wani na'urar SLS na al'ada, mai buɗaɗɗen gini (Tsarin Gwaji na Ƙara Laser - LAMPS) a UT Austin. An inganta sigogin aiki ta hanyar gwaji don rage lalacewar mai ɗauri da karkatar sashi (murgudawa):

• Ƙarfin Laser: 4 - 10 W
• Gudun Bincike: 200 - 1000 mm/s
• Kauri na Layer: 100 µm
• Tazarar Ƙyanƙyashe: 275 µm
• Girman Tabo na Laser (1/e²): 730 µm

Binciken ya daidaita ƙirar sashi na auna daga aikin SLS na polymer na baya (Allison et al.) don kimanta amincin siffofi.

3. Sakamako da Tattaunawa

Babban binciken shine cewa duk da cewa dokoki daga SLS na polymer suna ba da muhimmin farkon farawa, ba su isa ba don karkashin SLS na yumbu. Binciken ya tabbatar da cewa abubuwan kamar tasirin matakalai, mafi ƙaramin girman fasali, da iyakokin tsayawa suna nan amma an ƙara tsananta su ko kuma an canza su ta hanyar aikin yumbu. Misali, mafi ƙaramin diamita na rami ko faɗin tashoshi ba wai kawai girman tabon laser ke bayyana shi ba amma yana da tasiri sosai ta hanyar yin kwarara na cakuda foda, dankin narkewar mai ɗauri, da kuma kwanciyar hankali na foda da ba a haɗa ba yana tallafawa fasali yayin bugawa.

Ƙarin, iyakokin na musamman na yumbu da aka tsara sun haɗa da:

• Sarrafa Sashin Kore: Yanayin kore mai rauni, mai ɗauri ya sanya iyakoki masu tsauri akan bangon siriri da tsayawar da ba a tallafa ba idan aka kwatanta da sashi na polymer da aka haɗa.
• Ragewa da Karkacewa: Muhimmin ragewa, mara daidaituwa yayin ƙarfafawa bayan aiki (cire ɗauri & haɗawa) na iya karkatar da siffofin da aka tsara, yana buƙatar karkatarwa a cikin samfurin CAD.
• Cire Foda: Dole ne a tsara rikitattun tashoshi na ciki don ba da damar cire cikakken cakuda foda da ba a haɗa ba kafin ƙarfafawa, wani ƙuntatawa wanda bai fi tsanani a cikin SLS na polymer ba.

4. Cikakkun Bayanai na Fasaha da Tsarin Lissafi

Muhimmin siga a cikin SLS shine girman makamashi na ƙara ($E_v$), wanda ke tasiri narkewar mai ɗauri da haɗin sashi:

$E_v = \frac{P}{v \cdot h \cdot t}$

inda $P$ shine ƙarfin laser, $v$ shine gudun bincike, $h$ shine tazarar ƙyanƙyashe, kuma $t$ shine kaurin layer. Don karkashin SLS, taga mafi kyau na $E_v$ yana da kunkuntar—ƙasa sosai yana haifar da raunin gadoji na mai ɗauri, yayin da yawan yawa yana haifar da lalacewar mai ɗauri ko matsanancin damuwa na zafi.

Bugu da ƙari, mafi ƙaramin girman fasali ($d_{min}$) ana iya ƙididdige shi ta yin la'akari da faɗin haɗawa mai tasiri, wanda aiki ne na girman tabon laser ($w_0$), kaddarorin zafi na kayan, da girman makamashi:

$d_{min} \approx w_0 + \Delta x_{thermal}$

inda $\Delta x_{thermal}$ ke wakiltar watsawar zafi fiye da tabo. Don cakuda yumbu-polymer, ana canza wannan watsawa ta hanyar watsa zafi na cakuda.

5. Sakamakon Gwaji da Bayanin Ginshiƙi

Mahimman sakamakon gwaji na takarda sun samo asali ne daga sassan auna da aka gina. Duk da cewa an nuna takamaiman bayanan lamba na alumina amma ba a jera su sosai a cikin abin da aka ba da shafi ba, aikin yana nuni ga binciken baya (misali, Nolte et al.) wanda ya cim ma ramukan madaidaiciya tare da diamita na 1 mm ± 0.12 mm a cikin irin waɗannan tsarin. Babban "ginshiƙi" ko sakamako shine kwatanta na inganci da ƙididdiga na siffofi kamar:

• Filaye/Ramuka a Tsaye: Tantance diamita da da'irar da za a iya samu.
• Tashoshi a Kwance: Kimanta lalacewa ko rushewar tazarar da ba a tallafa ba.
• Kusurwoyin Tsayawa: Ƙayyade matsakaicin kusurwar da za a iya samu ba tare da tsarin tallafi ba.
• Kaurin Bango: Gano mafi ƙaramin kaurin bango mai tallafawa kansa.

Ƙarshe shine saitin gyare-gyaren jagororin zane waɗanda suka fi na SLS na polymer ra'ayi, musamman ga fasali masu kama da jirgin gini.

6. Tsarin Bincike: Nazarin Lamari Ba tare da Lamba ba

Lamari: Zana Na'urar Microreactor na Yumbu tare da Manifolds na Ciki

Manufa: Gina wani sashi na alumina tare da tashoshi na ciki na 500 µm don rarraba ruwa.

Aikace-aikacen Tsarin:

1. Shigo da Doka: Aiwatar da dokar SLS na polymer: mafi ƙaramin faɗin tashoshi ≈ 1.5 * girman tabo (≈1.1 mm). Ƙirar farko ta gaza don manufar 500 µm.
2. Binciken Musamman na Yumbu:
   • Ƙarfin Kore: Shin gadojin alumina-nylon na 500 µm zai iya tsira daga yada foda? Da alama a'a. Aiwatar da dokar yumbu: mafi ƙaramin tazara mai tallafawa kansa > 2 mm.
   • Cire Foda: Shin mashigar tashoshi/fitowar tashoshi suna da girma isa (misali, > 1.5 mm) don fitar da foda? Idan a'a, sake zana.
3. Ramon Ragewa: Aiwatar da ma'aunin ragewa mara daidaituwa (misali, 20%) zuwa samfurin CAD. A sanya faɗin tashoshi zuwa 625 µm a cikin zane don samar da ~500 µm bayan haɗawa.
4. Tabbitaccen Tabbaci: Buga takardun gwaji tare da tashoshi daga 0.8 mm zuwa 2.0 mm, auna bayan haɗawa, da kuma sabunta dokokin zane.

Wannan tsari, tsarin mataki-mataki yana motsawa fiye da aikace-aikacen dokar makanta zuwa tsarin zane mai sanin haɗari, mai dogaro da tabbaci.

7. Hangar Aikace-aikace da Hanyoyin Gaba

Jagororin zane da aka tabbatar sun ba da damar samar da ingantattun sassan yumbu don:

• Makamashi: Kayan aikin haɓakawa, sassan ƙwayoyin man fetur, da na'urorin musayar zafi tare da hanyoyin kwarara da aka keɓance don haɓaka inganci.
• Kiwon Lafiya: Abubuwan da aka saka na bioceramic na musamman ga majiyyaci tare da sararin samaniya da aka sarrafa don shigar da ƙashi.
• Sarrafa Sinadarai: Na'urorin gwaji akan guntu da ƙaƙƙarfan, rikitattun masu haɗawa.

Hanyoyin Bincike na Gaba:

1. Kayan Aiki Da Yawa & Tsarin Daraja: Bincika karkashin SLS don yumbu masu aiki da aka daraja ta hanyar bambanta abun ciki na cakuda foda layer-da-layer.
2. Sa ido kan Aiki a cikin Wuri: Haɗa hoton zafi (kamar yadda aka nuna a cikin takarda) da gano lahani don gyara siffa a ainihin lokaci, kamar ci gaban da aka samu a cikin LPBF na ƙarfe.
3. Koyon Injiniya don Zane: Haɓaka samfuran AI waɗanda ke shigar da aikin da ake so (misali, raguwar matsa lamba, sararin samaniya) da kuma fitar da siffofi masu iya gini masu bin iyakokin da aka gano, kama da ayyukan zane na haɓakawa a cikin ingantaccen tsarin topology.
4. Sabbin Tsarin Mai Dauri: Bincika masu ɗauri tare da ƙarfin kore mafi girma ko ƙananan yanayin zafi don sassauta wasu ƙuntatawa na siffofi.

8. Nassoshi

1. Gibson, I., Rosen, D., & Stucker, B. (2015). Additive Manufacturing Technologies: 3D Printing, Rapid Prototyping, and Direct Digital Manufacturing. Springer.
2. Deckers, J., Vleugels, J., & Kruth, J. P. (2014). Additive manufacturing of ceramics: a review. Journal of Ceramic Science and Technology, 5(4), 245-260.
3. Allison, J., et al. (2014). Metrology for the Process Development of Direct Metal Laser Sintering. Proceedings of the Solid Freeform Fabrication Symposium.
4. Nolte, H., et al. (2003). Laser Sintering of Ceramic Materials. Proceedings of the International Congress on Applications of Lasers & Electro-Optics.
5. Isola, P., Zhu, J. Y., Zhou, T., & Efros, A. A. (2017). Image-to-Image Translation with Conditional Adversarial Networks. Proceedings of the IEEE Conference on Computer Vision and Pattern Recognition (CVPR). (An ambata a matsayin misali na ingantattun tsarin lissafi masu dacewa da fassarar zane).
6. AMGTA. (2023). Ceramic Additive Manufacturing Market Report. Additive Manufacturing Green Trade Association. (Tushen waje don mahallin kasuwa).

9. Bincike na Asali & Sharhin Kwararru

Babban Fahimta: Wannan takarda tana ba da gaskiya mai mahimmanci, wanda aka yi watsi da shi sau da yawa a cikin ingantaccen masana'antu: fassarar aiki ba abu ne mai sauƙi ba. Zaton cewa dokokin zane suna iya canzawa tsakanin SLS na polymer da yumbu yana da haɗari mai sauƙi. Ainihin ƙimar a nan shine bayyana tsarin "harajin yumbu"—ƙarin ƙuntatawa na siffofi da yanayin kore mai rauni da rage girman jiki suka sanya. Wannan yana motsa fagen daga kwafi mara hankali zuwa sanannen zane, mai sanin aiki.

Kwararar Hankali & Ƙarfafawa: Hanyar aiki tana da ƙarfi. Ta yin amfani da ma'auni na sanannen SLS na polymer (sashin auna na Allison), sun kafa tushe mai sarrafawa. Amfani da na'urar al'ada, mai kayan aiki (LAMPS) babban ƙarfi ne, saboda yana ba da damar inganta sigogi fiye da akwatunan baƙar fata na na'urar kasuwanci, yana maimaita buƙatar buɗaɗɗen gine-gine a cikin bincike kamar yadda cibiyoyi kamar Lawrence Livermore National Laboratory suka haskaka a cikin aikinsu akan narkewar foda na laser. Mayar da hankali kan siffofi masu sauƙi, masu aunawa yana da hankali—yana ware tasirin siffofi daga sauran rikitattun abubuwa.

Kurakurai & Damuwar da aka rasa: Babban aibi shine rashin fitar da sakamakon dokokin zane masu ƙima. Takarda ta bayyana cewa akwai iyakoki amma ba ta ba da tebur mai bayyanawa, mai aiki ba (misali, "Mafi ƙaramin Kaurin Bango = X mm"). Ya fi zama tabbacin hanya don hanyar aiki fiye da jagorar zane da za a iya bayarwa. Bugu da ƙari, yayin da ake ambaton hoton zafi don haɓaka sigogi, ba ya amfani da wannan bayanan don haɗa tarihin zafi da karkacewar siffa ta ƙima, haɗin da aka kafa da kyau a cikin binciken AM na ƙarfe. Ana iya zurfafa binciken ta hanyar yin nuni ga samfuran lissafi kamar waɗanda ake amfani da su wajen kwaikwayon motsin haɗawa, wanda zai iya hasashen karkacewa kafin bugawa.

Fahimta Mai Aiki: Ga injiniyoyi, abin da za a ɗauka nan take shine aiwatar da dokokin SLS na polymer a matsayin farkon iyaka matsakaici, sannan a yi amfani da muhimman abubuwan tsaro (mai yiwuwa 1.5-2x don girman fasali) da tilas na zane-don-ramawar ragewa. Ga masu bincike, hanyar gaba a bayyane take: 1) Ƙididdige dokokin ta amfani da cikakken binciken DOE akan sashin auna. 2) Haɗa kwaikwayon lissafi mai yawa (misali, ta amfani da COMSOL ko Ansys Additive Suite) don ƙirar damuwa na zafi da abubuwan rage haɗawa, ƙirƙirar tagwaye na dijital na aikin. Wannan ya yi daidai da ƙarin canjin masana'antu zuwa AM mai dogaro da kwaikwayo, kamar yadda aka gani a cikin aikin kamfanoni kamar 3D Systems da EOS tare da kayan aikin kwaikwayonsu na keɓaɓɓe. Manufa ta ƙarshe ita ce rufe madauki, ta yin amfani da karkacewar siffa da aka auna a cikin wannan aikin don horar da samfuran koyon injina waɗanda ke gyara samfuran CAD ta atomatik, mai kama da ruhin cibiyoyin sadarwar fassarar hoto zuwa hoto kamar CycleGAN amma an yi amfani da su a fagen gyaran siffar CAD.