Hiki ke hoʻololi ʻia nā ʻāpana tungsten hou i ka Schuh Group ma MIT ke hoʻololi i ka uranium i hoʻopau ʻia i nā projectiles hoʻopaʻa kaua. Eha-makahiki mea 'epekema a me ka 'enekinia haumāna puka 'o Zachary C. Cordero e hana ana ma ka haʻahaʻa-ʻawaʻawa, kiʻekiʻe-ikaika, kiʻekiʻe-density mea no ka hoʻololi depleted uranium i structural pūʻali noi. Hoʻopilikia ka uranium i nā koa a me nā makaʻāinana. "ʻO ia ke kumu o ka hoʻāʻo ʻana e pani," wahi a Cordero.

ʻO ka tungsten maʻamau ka halo a i ʻole ka pōpō i ka hopena, ʻo ka hana ʻino loa. No laila, ʻo ka paʻakikī ka hoʻomohala ʻana i kahi huila e hiki ke hoʻohālikelike i ka hana o ka uranium pau ʻole, a lilo ia i mea hoʻokala iā ia iho i ka wā e ʻako ai i nā mea a mālama i ka ihu ʻoi ma ka ʻaoʻao penetrator-target interface. "ʻO Tungsten wale nō ka ikaika a paʻakikī. Hoʻokomo mākou i nā mea hoʻohui ʻē aʻe e hana ai i hiki iā mākou ke hoʻohui i kēia mea nui, "wahi a Cordero.

A tungsten alloy me chromium a me ka hao (W-7Cr-9Fe) ua nui ka ikaika ma mua o ka kalepa tungsten alloys, Cordero hoike ma ka pepa me ka mea kākau kiʻekiʻe a me ka 'Oihana o Materials Science a me ka 'enekinia poʻo Christopher A. Schuh a me nā hoa ma ka puke pai Metallurgical a me Materials. Nā Hana A. Ua hoʻokō ʻia ka hoʻomaikaʻi ʻana ma ka hoʻopaʻa ʻana i nā pauka metala i loko o kahi paʻi wela sintering i kōkua ʻia e ke kula, me ka hopena maikaʻi loa, ana ʻia e ke ʻano o ka palaoa maikaʻi a ka paʻakikī kiʻekiʻe loa, loaʻa i ka manawa hana o 1 minuke ma 1,200 degere Celsius. ʻO ka lōʻihi o ka hana ʻana a me ke kiʻekiʻe o ka mahana i alakaʻi ʻia i ka ʻai ʻoi aʻe a me ka hana mechanical nāwaliwali. Co-authors komo MIT 'enekinia a me nā mea 'epekema puka haumāna Mansoo Park, Oak Ridge postdoctoral hoa Emily L. Huskins, Boise State Associate Professor Megan Frary a me ka haumāna puka Steven Lives, a me ka Army Research Laboratory mechanical engineer a me ka hui alakaʻi Brian E. Schuster. Ua hana pū ʻia nā hoʻokolohua ballistic sub-scale o ka tungsten-chromium-iron alloy.

"Inā hiki iā ʻoe ke hana i ka nanostructured a i ʻole amorphous bulk tungsten (alloy), pono ia he mea ballistic kūpono," wahi a Cordero. Ua loaʻa iā Cordero, he kamaʻāina ʻo Bridgewater, NJ, he National Defense Science and Engineering (NDSEG) Fellowship ma 2012 ma o ka Air Force Office of Scientific Research. Kākoʻo ʻia kāna noiʻi e ka US Defense Threat Reduction Agency.

ʻO ke ʻano o ka palaoa ultrafine

"ʻO ke ala aʻu e hana ai i kaʻu mau mea me ka hana pauka kahi e hana mua ai mākou i ka pauka nanocrystalline a laila hoʻohui mākou i mea nui. Akā ʻo ka paʻakikī ʻo ka hoʻohui ʻana e pono ai ka hoʻolaha ʻana i nā mea i nā mahana kiʻekiʻe, "wahi a Cordero. ʻO ka hoʻomehana ʻana i nā mea hoʻoheheʻe i nā wela kiʻekiʻe e hiki ke hoʻonui i nā kīʻaha, a i ʻole nā ​​​​kānāwai crystalline pākahi, i loko o ka metala e hoʻonui ai iā lākou. Ua hiki iā Cordero ke hoʻokō i ke ʻano o ka palaoa ultrafine ma kahi o 130 nanometers i ka W-7Cr-9Fe compact, i hōʻoia ʻia e nā micrographs electron. "Me ka hoʻohana ʻana i kēia ala kaʻina hana pauka, hiki iā mākou ke hana i nā laʻana nui a hiki i 2 kenimika ke anawaena, a i ʻole hiki iā mākou ke hele nui aku, me nā ikaika compressive ikaika o 4 GPa (gigapascals). ʻO ka ʻoiaʻiʻo hiki iā mākou ke hana i kēia mau mea me ka hoʻohana ʻana i kahi kaʻina scalable ʻoi aku ka maikaʻi, "wahi a Cordero.

"ʻO ka mea a mākou e hoʻāʻo nei e hana ma ke ʻano he hui e hana i nā mea nui me nā nanostructure maikaʻi. ʻO ke kumu e makemake ai mākou no ka mea he mau waiwai hoihoi loa kēia mau mea i hiki ke hoʻohana ʻia i nā noi he nui, "hoʻohui ʻo Cordero.

ʻAʻole i loaʻa ma ke ʻano

Ua nānā pū ʻo Cordero i ka ikaika o nā pauka metala me nā microstructures nanoscale i loko o kahi pepa puke moʻolelo Acta Materialia. Ua hoʻohana ʻo Cordero, me ka mea kākau kiʻekiʻe ʻo Schuh, i nā simulation computational a me nā hoʻokolohua hoʻokolohua e hōʻike ai i nā huila o nā metala e like me ka tungsten a me ka chromium me nā ikaika mua like e like me ka homogenize a hana i kahi huahana hopena ikaika, akā ʻo ka hui pū ʻana o nā metala me ka ikaika mua nui like ʻole. e like me ka tungsten a me ka zirconium e hana i kahi mea hoʻohui nāwaliwali me ka ʻoi aku o hoʻokahi māhele i kēia manawa.

“ʻO ke kaʻina hana o ka wili pōleʻa kiʻekiʻe he hiʻohiʻona o ka ʻohana nui o nā kaʻina hana e hoʻololi ai ʻoe i ka heck mai nā mea e hoʻohuli ai i kāna microstructure i loko o kahi kūlana kūlike ʻole. ʻAʻohe papa hana maikaʻi no ka wānana ʻana i ka microstructure e puka mai ana, no laila he nui nā manawa he hoʻāʻo a hewa kēia. Ua hoʻāʻo mākou e wehe i ka empiricism mai ka hoʻolālā ʻana i nā alloys e hoʻokumu i kahi hopena paʻa metastable, ʻo ia kekahi o nā hiʻohiʻona o kahi pae ʻole equilibrium, "wahi a Cordero.

"Hoʻopuka ʻoe i kēia mau ʻāpana kaulike ʻole, nā mea āu e ʻike ʻole ai ma ka honua a puni ʻoe, ma ke ʻano, me ka hoʻohana ʻana i kēia mau kaʻina deformation koʻikoʻi," wahi āna. ʻO ke kaʻina hana o ka wili pōleʻa ikaika nui e pili ana i ka ʻako hou ʻana i nā pauka metala me ka ʻako ʻana i nā mea hoʻohuihui e hui pū i ka wā e hoʻokūkū ai, ʻo nā kaʻina hana hoʻihoʻi thermally-activated e hoʻihoʻi i ka huila i kona kūlana kaulike, a i nā manawa he nui ke kaʻawale. . "No laila aia kēia hoʻokūkū ma waena o kēia mau kaʻina hana ʻelua," wehewehe ʻo Cordero. Hāʻawi kāna pepa i kahi kumu hoʻohālike maʻalahi e wānana i nā kemika i loko o kahi huila i hāʻawi ʻia e hana i kahi hopena paʻa a hōʻoia ʻia me nā hoʻokolohua. "ʻO nā pauka as-milled kekahi o nā metala paʻakikī a nā kānaka i ʻike ai," wahi a Cordero, me ka ʻike ʻana i nā hōʻike i hōʻike ʻia i ka tungsten-chromium alloy he nanoindentation hardness o 21 GPa. ʻO ia ka mea e hoʻopālua ai i ka paʻakikī nanoindentation o nā mea hao hao nanocrystalline a i ʻole tungsten coarse-grained.

Pono ka metallurgy i ka maʻalahi

Ma ka ultrafine grain tungsten-chromium-iron alloy compacts āna i aʻo ai, ua ʻohi nā huila i ka hao mai ka abrasion o ka media wili kila a me ka vial i ka wā o ka wili pōpō ikaika. "Akā hiki ke lilo i ʻano mea maikaʻi, no ka mea, ʻo ia ka mea e hoʻolōʻihi i ka densification i nā haʻahaʻa haʻahaʻa, e hōʻemi ana i ka nui o ka manawa āu e hoʻolilo ai i kēlā mau wela kiʻekiʻe e hiki ke alakaʻi i nā loli maikaʻi ʻole i ka microstructure," Ua wehewehe ʻo Cordero. "ʻO ka mea nui ka maʻalahi a me ka ʻike ʻana i nā manawa i ka metallurgy."

Ua puka 'o Cordero mai MIT i ka makahiki 2010 me ka bachelor's in physics a ua hana no ho'okahi makahiki ma Lawrence Berkeley National Lab. Ma laila, ua hoʻoikaika ʻia ʻo ia e nā limahana ʻenekinia i aʻo mai ka hanauna mua o nā metallurgists i hana i nā crucibles kūikawā e paʻa i ka plutonium no ka Manhattan Project i ka wā o ke Kaua Honua II. "ʻO ka lohe ʻana i ke ʻano o nā mea a lākou e hana nei, ua hauʻoli nui wau a makemake nui i ka hana metala. He leʻaleʻa wale nō ia, "wahi a Cordero. Ma nā haʻawina ʻepekema ʻē aʻe, ʻōlelo ʻo ia, "ʻAʻole hiki iā ʻoe ke wehe i kahi umu ma 1,000 C, a ʻike i kahi mea ʻulaʻula ʻulaʻula. ʻAʻole hiki iā ʻoe ke hana wela i nā mea. Manaʻo ʻo ia e hoʻopau i kāna PhD i 2015.

ʻOiai ʻo kāna hana i kēia manawa e kālele ana i nā noi hoʻolālā, hoʻohana pū ʻia ke ʻano o ka hoʻoheheʻe ʻana i ka pauda e hana ai i nā mea magnetic. "Hiki ke hoʻohana ʻia ka nui o ka ʻike a me ka ʻike i nā mea ʻē aʻe," wahi āna. "ʻOiai ʻo kēia ka metallurgy structural kuʻuna, hiki iā ʻoe ke hoʻohana i kēia metallurgy kula kahiko i nā mea kula hou."