Ma aloyi atsopano a tungsten omwe akupangidwa mu Gulu la Schuh ku MIT atha kulowa m'malo mwa uranium yomwe yatha muzoboola zida zankhondo. Zachary C. Cordero wazaka zachinayi akugwiritsa ntchito zinthu zotsika kawopsedwe, zamphamvu kwambiri, zokhala ndi kachulukidwe kwambiri kuti alowe m'malo mwa uranium yomwe yatha m'machitidwe ankhondo. Uranium yatha imatha kukhala pachiwopsezo cha thanzi kwa asitikali ndi anthu wamba. "Ndicho chilimbikitso choyesera kubwezeretsa," akutero Cordero.

Tungsten wamba amatha kukhala bowa kapena osagwira bwino ntchito, ntchito yoyipa kwambiri. Chifukwa chake vuto ndi kupanga aloyi yomwe ingafanane ndi magwiridwe antchito a uranium yatha, yomwe imakhala yodzinola yokha pamene imameta zakuthupi ndikusunga mphuno yakuthwa pamalo olowera. "Tungsten palokha ndi yamphamvu kwambiri komanso yovuta. Timayika zinthu zina zophatikizira kuti tithe kuziphatikiza kukhala chinthu chochulukachi, "akutero Cordero.

Aloyi ya tungsten yokhala ndi chromium ndi chitsulo (W-7Cr-9Fe) inali yamphamvu kwambiri kuposa ma aloyi a tungsten amalonda, Cordero adanenanso mu pepala ndi wolemba wamkulu komanso mutu wa dipatimenti ya Materials Science and Engineering Christopher A. Schuh ndi anzawo m'magazini ya Metallurgical and Materials Zochita A. Kuwongolerako kudatheka pophatikiza ufa wazitsulo mu makina osindikizira otentha a sintering, ndi zotsatira zabwino kwambiri, zoyezedwa ndi kapangidwe kabwino ka tirigu ndi kuuma kwapamwamba kwambiri, komwe kumatheka panthawi yokonza mphindi imodzi pa 1,200 digiri Celsius. Kuchulukirachulukira kwa nthawi yokonza ndi kutentha kwambiri kumapangitsa kuti mbewuzo ziwonjezeke komanso kusagwira bwino ntchito kwamakina. Olemba nawo anaphatikizapo wophunzira maphunziro a MIT engineering ndi materials science Mansoo Park, Oak Ridge postdoctoral mnzake Emily L. Huskins, Boise State Associate Pulofesa Megan Frary ndi wophunzira womaliza maphunziro Steven Livers, ndi Army Research Laboratory makina injiniya ndi mtsogoleri wa gulu Brian E. Schuster. Mayeso ang'onoang'ono amtundu wa tungsten-chromium-iron alloy achitidwanso.

"Ngati mutha kupanga nanostructured kapena amorphous bulk tungsten (aloyi), iyenera kukhala chinthu chabwino kwambiri," akutero Cordero. Cordero, mbadwa ya Bridgewater, NJ, adalandira National Defense Science and Engineering (NDSEG) Fellowship mu 2012 kudzera mu Air Force Office of Scientific Research. Kafukufuku wake amathandizidwa ndi US Defense Threat Reduction Agency.

Mapangidwe ambewu ya Ultrafine

"Momwe ndimapangira zida zanga ndikupangira ufa pomwe timapanga ufa wa nanocrystalline kenako timauphatikiza kukhala chinthu chochuluka. Koma vuto ndilakuti kuphatikiza kumafuna kuulula zinthuzo ku kutentha kwakukulu, "akutero Cordero. Kutenthetsa ma alloys ku kutentha kwakukulu kungayambitse njere, kapena madera amtundu wa crystalline, mkati mwazitsulo kuti akule, zomwe zimawafooketsa. Cordero adatha kukwaniritsa kapangidwe kambewu ka ultrafine pafupifupi 130 nanometers mu W-7Cr-9Fe compact, yotsimikiziridwa ndi ma electron micrographs. "Pogwiritsa ntchito njira yopangira ufa, titha kupanga zitsanzo zazikulu mpaka 2 centimita m'mimba mwake, kapena titha kukula, ndi mphamvu zolimba za 4 GPa (gigapascals). Zoti titha kupanga zidazi pogwiritsa ntchito njira yowongoka mwina ndizosangalatsa kwambiri, "akutero Cordero.

"Zomwe tikuyesera kuchita monga gulu ndikupanga zinthu zambiri ndi ma nanostructures abwino. Chifukwa chomwe tikufuna kutero ndichifukwa choti zidazi zili ndi zinthu zosangalatsa kwambiri zomwe zitha kugwiritsidwa ntchito pazinthu zambiri, "akuwonjezera Cordero.

Osapezeka m'chilengedwe

Cordero adawunikanso mphamvu ya ufa wazitsulo wokhala ndi ma nanoscale microstructures mu pepala la Acta Materialia. Cordero, ndi wolemba wamkulu Schuh, adagwiritsa ntchito zoyeserera zamakompyuta komanso kuyesa kwa labotale kuti awonetse kuti ma aloyi azitsulo monga tungsten ndi chromium okhala ndi mphamvu zofananira zoyambira amatha kupanga homogenize ndikupanga chomaliza champhamvu, pomwe kuphatikiza zitsulo zokhala ndi mphamvu yayikulu yosagwirizana ndi izi. monga tungsten ndi zirconium zimakonda kutulutsa aloyi wocheperako wokhala ndi gawo limodzi.

"Mchitidwe wa mphero yamphamvu kwambiri ya mpira ndi chitsanzo chimodzi cha banja lalikulu la njira zomwe mumasokoneza zinthu kuti muyendetse kachitidwe kake kakang'ono kamene kamakhala kosafanana. Palibe dongosolo labwino lolosera za microstructure zomwe zimatuluka, choncho nthawi zambiri izi zimakhala zoyeserera komanso zolakwika. Tinkayesa kuchotsa mphamvu kuti tipange ma alloys omwe apanga njira yolimba, yomwe ndi chitsanzo chimodzi cha gawo losagwirizana, "akutero Cordero.

"Mumapanga magawo osagwirizana, zinthu zomwe simukanaziwona m'chilengedwe chakuzungulirani, mwachilengedwe, pogwiritsa ntchito njira zopunduka kwambiri," akutero. Njira yopangira mphero yamphamvu kwambiri imaphatikizapo kumeta mobwerezabwereza kwa ufa wachitsulo ndikumeta ndikumeta ndikuyendetsa zinthu za alloying kuti ziphatikizire kupikisana pamene mukupikisana, njira zotsitsimula zomwe zimayendetsedwa ndi thermally zimalola kuti alloy abwerere ku chikhalidwe chake chofanana, chomwe nthawi zambiri chimakhala chosiyana. . "Chifukwa chake pali mpikisano pakati pa njira ziwirizi," akufotokoza Cordero. Pepala lake lidapereka chitsanzo chosavuta cholosera zamakhemistri mu aloyi yopatsidwa yomwe ipanga yankho lolimba ndikulitsimikizira ndi zoyeserera. "Maufa opangidwa ngati mphero ndi zina mwazitsulo zolimba kwambiri zomwe anthu adaziwona," akutero Cordero, pozindikira mayeso adawonetsa kuti aloyi ya tungsten-chromium ili ndi kuuma kwa nanoindentation kwa 21 GPa. Izi zimawapangitsa kukhala owirikiza kawiri kuuma kwa nanoindentation kwa nanocrystalline iron-based alloys kapena coarse-grained tungsten.

Metallurgy imafuna kusinthasintha

Mu ultrafine njere tungsten-chromium-chitsulo aloyi compacts iye anaphunzira, aloyi anatola chitsulo kuchokera abrasion wa zitsulo akupera TV ndi vial pa mkulu-mphamvu mpira mphero. "Koma zikuwoneka kuti zingakhalenso zabwino, chifukwa zikuwoneka kuti zimathandizira kachulukidwe pamatenthedwe otsika, zomwe zimachepetsa nthawi yomwe muyenera kuthera pa kutentha kwakukulu komwe kungayambitse kusintha koyipa kwa microstructure," adatero. Cordero akufotokoza. "Chinthu chachikulu ndikusinthasintha ndikuzindikira mwayi wazitsulo."

Cordero adamaliza maphunziro awo ku MIT mu 2010 ndi bachelor's in physics ndipo adagwira ntchito kwa chaka chimodzi ku Lawrence Berkeley National Lab. Kumeneko, adalimbikitsidwa ndi ogwira ntchito zauinjiniya omwe adaphunzira kuchokera kwa am'badwo wakale wa metallurgists omwe adapanga ma crucible apadera kuti agwire plutonium ku Manhattan Project pa Nkhondo Yachiwiri Yapadziko Lonse. “Kumva za mtundu wa zinthu zomwe amagwirira ntchito kunandisangalatsa kwambiri ndikufunitsitsa kukonza zitsulo. Ndizosangalatsanso kwambiri, "akutero Cordero. M'magulu ena a sayansi yazinthu, akuti, "Simungathe kutsegula ng'anjo pa 1,000 C, ndikuwona china chake chonyezimira chofiyira. Simuyenera kuchita zinthu zotenthetsa. Akuyembekeza kumaliza PhD yake mu 2015.

Ngakhale kuti ntchito yake yamakono ikuyang'ana pa ntchito zamapangidwe, mtundu wa ufa womwe akupanga umagwiritsidwanso ntchito popanga maginito. "Zidziwitso zambiri ndi chidziwitso zitha kugwiritsidwa ntchito pazinthu zina," akutero. "Ngakhale izi ndizitsulo zamapangidwe achikhalidwe, mutha kugwiritsa ntchito zitsulo zamasukulu akale ku zida zapasukulu zatsopano."