Sabbin allunan tungsten da ake haɓakawa a cikin ƙungiyar Schuh a MIT na iya maye gurbin uranium da ba a ƙare ba a cikin kayan aikin sokin sulke. Zachary C. Cordero mai shekaru huɗu na kayan kimiyya da injiniyan injiniya wanda ya kammala karatun digiri yana aiki akan ƙarancin guba, ƙarfi mai ƙarfi, kayan ɗimbin yawa don maye gurbin uranium da ta lalace a aikace-aikacen soja na tsari. Ragewar uranium na haifar da hatsarin lafiya ga sojoji da farar hula. "Wannan shine dalilin ƙoƙarin maye gurbinsa," in ji Cordero.

Tungsten na al'ada zai iya yin naman kaza ko kuma ya bushe akan tasiri, mafi munin aikin da zai yiwu. Don haka ƙalubalen shine samar da gawa wanda zai iya dacewa da aikin ƙarancin uranium, wanda ya zama mai kaifi yayin da yake yanke kayan kuma yana kiyaye hanci mai kaifi a wurin mahaɗar mai shiga. "Tungsten da kanta yana da ƙarfi na musamman da wuya. Mun sanya wasu abubuwan da za su iya haɗawa da shi ta yadda za mu iya haɗa shi cikin wannan babban abu,” in ji Cordero.

Tungsten gami da chromium da baƙin ƙarfe (W-7Cr-9Fe) ya fi ƙarfin tungsten gami na kasuwanci, Cordero ya ruwaito a cikin wata takarda tare da babban marubuci kuma shugaban Sashen Kimiyya da Injiniya Christopher A. Schuh da abokan aiki a cikin mujallar Metallurgical and Materials. Ma'amaloli A. An sami ci gaba ta hanyar ƙaddamar da foda na ƙarfe a cikin wani filin da aka taimaka mai zafi mai zafi, tare da sakamako mafi kyau, wanda aka auna ta hanyar kyakkyawan tsarin hatsi da kuma mafi girma, wanda aka samu a lokacin sarrafawa na 1 minti a 1,200 digiri Celsius. Tsawon lokacin sarrafawa da yanayin zafi ya haifar da ƙarancin hatsi da ƙarancin aikin injina. Co-marubuta sun hada da MIT injiniya da kayan kimiyyar digiri dalibi Mansoo Park, Oak Ridge postdoctoral takwara Emily L. Huskins, Boise State Mataimakin Farfesa Megan Frary da digiri na biyu dalibi Steven Lives, da Army Research Laboratory inji injiniya da kuma tawagar Brian E. Schuster. Hakanan an yi gwaje-gwajen ƙananan sikelin ballistic na tungsten-chromium-iron gami.

"Idan za ku iya yin ko dai nanostructured ko amorphous girma tungsten (gawa), ya kamata da gaske ya zama manufa ballistic abu," in ji Cordero. Cordero, ɗan asalin Bridgewater, NJ, ya sami haɗin gwiwar Kimiyyar Tsaro da Injiniya (NDSEG) a cikin 2012 ta Ofishin Sojojin Sama na Binciken Kimiyya. Hukumar rage barazanar tsaro ta Amurka ce ta dauki nauyin bincikensa.

Tsarin hatsi na Ultrafine

“Hanyar da nake yin kayana ita ce sarrafa foda inda muka fara yin nanocrystalline powder sannan mu hada shi ya zama babban abu. Amma kalubalen shine ƙarfafawa yana buƙatar fallasa kayan zuwa yanayin zafi mai girma, "in ji Cordero. Dumama alluran zuwa yanayin zafi na iya haifar da hatsi, ko yanki na crystalline guda ɗaya, a cikin ƙarfe don haɓaka, wanda ke raunana su. Cordero ya sami damar cimma tsarin hatsi na ultrafine na kusan nanometer 130 a cikin ƙaramin W-7Cr-9F, wanda na'urorin lantarki suka tabbatar. "Amfani da wannan hanyar sarrafa foda, za mu iya yin manyan samfurori har zuwa santimita 2 a diamita, ko kuma za mu iya girma, tare da ƙarfin matsa lamba na 4 GPa (gigapascals). Gaskiyar cewa za mu iya yin waɗannan kayan ta amfani da tsari mai ƙima wataƙila ma ya fi ban sha'awa, "in ji Cordero.

“Abin da muke ƙoƙarin yi a matsayin ƙungiya shine yin manyan abubuwa tare da kyawawan nanostructures. Dalilin da muke son hakan shine saboda waɗannan kayan suna da kaddarorin masu ban sha'awa waɗanda ke da yuwuwar amfani a aikace-aikace da yawa, "in ji Cordero.

Ba a samu a yanayi ba

Cordero ya kuma bincika ƙarfin ƙoshin ƙarfe na ƙarfe tare da nanoscale microstructures a cikin takardar mujallar Acta Materialia. Cordero, tare da babban marubucin Schuh, ya yi amfani da na'urorin ƙididdiga da gwaje-gwajen gwaje-gwajen gwaje-gwaje don nuna cewa gami da ƙarfe irin su tungsten da chromium tare da ƙarfin farko iri ɗaya suna son haɓakawa da samar da samfurin ƙarshe mai ƙarfi, yayin da haɗuwa da ƙarfe tare da babban ƙarfin farko bai dace ba. kamar yadda tungsten da zirconium ke son samar da gawa mai rauni tare da fiye da lokaci guda.

“Tsarin injin niƙa mai ƙarfi shine misali ɗaya na babban dangi na tsari wanda zaku lalata kayan aiki don fitar da ƙananan tsarinsa zuwa wani yanayi mara daidaituwa. Babu wani tsari mai kyau da gaske don tsinkayar microstructure wanda ke fitowa, don haka sau da yawa wannan shine gwaji da kuskure. Muna ƙoƙarin cire haƙƙin haƙƙin haƙƙin haƙƙin haƙƙin haƙƙin haƙƙin ƙira waɗanda za su samar da ingantaccen bayani mai ƙarfi, wanda shine misali ɗaya na lokacin rashin daidaito, ”in ji Cordero.

"Kuna samar da waɗannan matakan marasa daidaituwa, abubuwan da ba za ku iya gani ba a duniyar da ke kewaye da ku, a cikin yanayi, ta amfani da waɗannan matakan nakasawa," in ji shi. Tsarin ƙwallo mai ƙarfi mai ƙarfi ya haɗa da maimaita juzu'in foda na ƙarfe tare da ɓacin rai yana tuƙi abubuwan haɗin gwiwa don haɗawa yayin fafatawa, hanyoyin dawo da wutar lantarki mai kunnawa suna ba da damar gami don komawa yanayin daidaiton sa, wanda a yawancin lokuta shine a raba lokaci. . "Don haka akwai wannan gasa tsakanin waɗannan matakai guda biyu," in ji Cordero. Takardarsa ta ba da shawarar samfuri mai sauƙi don hango hasashen sunadarai a cikin abin da aka ba da shi wanda zai samar da ingantaccen bayani kuma ya inganta shi tare da gwaje-gwaje. Cordero ya ce, "Furs ɗin da ake niƙa su ne wasu ƙananan ƙarfe waɗanda mutane suka gani," in ji Cordero, lura da gwaje-gwajen da aka yi sun nuna tungsten-chromium gami yana da taurin nanoindentation na 21 GPa. Wannan ya sa su kusan ninki biyu na nanoindentation tauri na nanocrystalline tushen gabobin ƙarfe ko kuma tungsten mai ƙwanƙwasa.

Ƙarfe na buƙatar sassauci

A cikin ultrafine hatsi tungsten-chromium-iron gami compacts da ya yi nazari, gami da tsince baƙin ƙarfe daga abrasion na karfe nika kafofin watsa labarai da vial a lokacin high-makamashi ball milling. "Amma ya juya cewa hakan na iya zama nau'in abu mai kyau, saboda yana kama da yana haɓaka haɓakawa a cikin ƙananan yanayin zafi, wanda ke rage yawan lokacin da za ku kashe a waɗannan yanayin zafi mai zafi wanda zai iya haifar da mummunan canje-canje a cikin ƙananan ƙwayoyin cuta," Cordero yayi bayani. "Babban abu shine sassauƙa da fahimtar damammaki a cikin ƙarfe."

Cordero ya sauke karatu daga MIT a 2010 tare da digiri na farko a fannin kimiyyar lissafi kuma ya yi aiki na shekara guda a Lawrence Berkeley National Lab. A can, ma'aikatan injiniya sun yi wahayi zuwa gare shi waɗanda suka koya daga ƙarni na farko na masana'antar ƙarfe waɗanda suka yi crucibles na musamman don riƙe plutonium don aikin Manhattan a lokacin Yaƙin Duniya na II. “Jin irin kayan da suke aiki da su ya sa na yi farin ciki da sha’awar sarrafa karafa. Hakanan abin farin ciki ne kawai, ”in ji Cordero. A cikin wasu ƙa'idodin kimiyyar kayan aiki, ya ce, “Ba za ku iya buɗe tanderu a 1,000 C ba, ku ga wani abu yana haskaka ja da zafi. Ba za ku iya yin maganin zafi ba." Yana sa ran kammala karatunsa na PhD a shekarar 2015.

Ko da yake aikinsa na yanzu yana mai da hankali kan aikace-aikacen tsari, nau'in sarrafa foda da yake yi ana amfani da shi don yin kayan maganadisu. "Yawancin bayanai da ilimin za a iya amfani da su ga wasu abubuwa," in ji shi. "Ko da yake wannan tsarin karafa ne na al'ada, kuna iya amfani da wannan tsohuwar makarantar karafa ga sabbin kayan makaranta."