Icyuma
Icyuma (kiva mu kilatini cultellus, kigabanya umuyaga ni ukuvuga "icyuma"

cy'isuka) ni igikoresho gikoreshwa mu gutema. Mubisanzwe bigizwe nicyuma kimwe gifite icyerekezo kimwe cyangwa byinshi bikarishye bifatanye nigitoki. Icyuma cyakoreshejwe nk'ibikoresho n'intwaro kuva mu Kibuye kugeza mu ntangiriro y'ubumuntu. Anthropologiste bemeza ko icyuma ari kimwe mu bikoresho bya mbere byakozwe n'abantu kugira ngo babeho.

Icyuma cya mbere cyari gikozwe muri flint cyangwa obsidian, gikata cyangwa gisizwe ku nkombe imwe, rimwe na rimwe gifite ibikoresho. Nyuma hamwe niterambere ryo gushonga na metallurgie ibyuma byasimbuwe mbere n'umuringa, hanyuma umuringa, ibyuma nicyuma hanyuma bisimbuzwa ibyuma. Mugihe ibikoresho byahindutse mugihe, igishushanyo cyibanze gikomeza kuba kimwe.

Hamwe n'akabuto n'ikiyiko, icyuma cyabaye igikoresho rusange cyo gukoresha cyane mu bihugu by’iburengerazuba byibuze kuva mu gihe cyo hagati. Uyu munsi, ibyuma byinshi bikoreshwa mugikoni. Foldaway hamwe nicyuma cyumufuka wibyuma biroroshye gutwara, kuboneka ahantu hose. Akamaro k'icyuma nk'intwaro hari ukuntu gatwikiriwe no kuvuka kw'intwaro zikora neza kandi zihariye, ariko icyuma ni impano y'ingabo zose.

Amavu n'amavuko 
Inkomoko y'ibikoresho byatangiye mu mwaka igihumbi, igihe umusaruro wibyuma wateye imbere cyane. Icyuma cya mbere cyari gifite imbogamizi nyinshi: byatakaje byoroshye ubukana bwicyuma, kandi bisaba koza isuku yibara ryasizwe nibintu birimo ibiryo. Kubera iyo mpamvu, kugeza mu kinyejana cya 13, ibiryo byatanzwe bimaze gucibwa, no gushyira inyama nibindi biryo byakoreshejwe

guhiga kugiti cyawe cyangwa kurwana. Uruganda rukora ibyuma rwose rwanditswe muri Florence guhera mu 1244, kandi mu gihe cya Renaissance, hamwe n’iterambere ry’ubuhanga bwo gutunganya ibyuma, amahugurwa akomeye y’ibicuruzwa yavukiye mu bwami bwa Milan no muri Repubulika ya Venise.

Ibisobanuro

Itegekonshinga ry'icyuma 
Ibintu bikunze kugaragara mubyuma birimo imitako ikora cyangwa irimbisha imitako gusa, harimo ibice, umwobo, seriveri inyuma, hamwe na groove yo gufata. "Urusenda" rimwe na rimwe ruvugwa mu buryo butari bwo "amaraso" cyangwa "igikoma cy'amaraso" ni depression ku cyuma. Bamwe bibeshye bemeza ko iri shyamba rishyigikira gutoroka amaraso mu gikomere cyatewe nintwaro, ariko imikorere yacyo nyayo ni ukworohereza icyuma utagabanije guhangana nacyo kandi ku byuma byinshi ni ikintu cyiza gusa. Hejuru y'ibyo, umwobo uri ku cyuma urashobora kugabanya kugabanya ubushyamirane buri hagati y’icyuma n’ibikoresho arimo gutema, bigatuma icyuma cyimuka cyangwa kigakuramo imbaraga nke.

Ibyuma bimwe bifite, hafi yisangano ryicyuma hamwe nigitoki, "umukufi", aho icyuma kidakaze. Umukufi mugufi ukora kugirango wirinde gufata urutoki igihe inkota ikarishye, mugihe amakariso maremare ashobora kuba nkinkunga yinyongera yintoki. Igikoresho gishobora kuba kigizwe nibikoresho byinshi bitandukanye, ikoreshwa cyane ni ibiti nicyuma, ariko nibindi bikoresho byo gushushanya bikunze kuboneka. Akenshi usanga hari umwobo munsi yumukingo, igufasha kumanika icyuma, kuyihambira ku ndobo cyangwa kuyizirika ku kuboko kugirango wirinde kunyerera.

Hariho amajana yibigo bikora ibyuma. Rimwe na rimwe, bibaho ko ijambo "ibyuma bidafite ingese" biboneka ku byuma byinshi bitiranya nk'ikirango cy'icyuma ubwacyo, ariko nta kindi uretse izina ry'ubwoko bw'ibyuma bikoreshwa mu gukora icyuma. Ibyuma bitagira umwanda bisobanura ibyuma bitagira umwanda, mubyukuri ibyuma bitagira umwanda byitwa ibyuma bitagira umwanda. Hariho amajana yandi maduka mato akora ibyuma, akenshi kabuhariwe muburyo bwihariye cyangwa gukora ibyuma byabugenewe. Gukora ni ikintu gikundwa cyane, gishoboka mugusya cyangwa gutanga ibyuma ukoresheje intoki, kubihimba cyangwa gukoresha inzira zombi.

Ibikoresho 
Ubusanzwe ibyuma bikozwe mu byuma. Ibyuma byose byuma birakomeye, ni ukuvuga martensite igizwe nuburyo bwiza cyane bwa kristaline ifite ibitagenda neza muri kasike ya kristu ikomera ibikoresho. Ikorwa no gukonjesha byihuse, mumazi cyangwa amavuta, ibyuma bizanwa mubushyuhe bwinshi. Kuri ubu bushyuhe ibyuma bifata imiterere ya kristaline ya austenitis kandi, kubera ubukonje bwihuse, inyura mumiterere ya martensitike, ikomeye cyane ariko yoroheje. Kugira ngo igabanye intege nke zayo, icyuma gikorerwa inzira yubushyuhe igizwe no gushyushya icyuma ku bushyuhe buri munsi y’ubushyuhe bukabije mu gihe gihagije no kugikonjesha mu buryo budakabije. Icyuma cyuma akenshi gifite nikel nkeya, kuko iki kintu gikunda guhagarika austenite no mubushyuhe buke. Ibyuma bya karubone nyinshi ariko ibyuma bya chromium bitanga imbaraga cyane, ariko ingese hamwe nibishobora kwangirika niba bidahumanye, byumye kandi bisizwe amavuta.

Icyuma kitagira ibyuma cyamamaye cyane kuva igice cya kabiri cyikinyejana cya 20. Ibyuma bitagira umuyonga ku byuma ni ibyuma birimo chromium nyinshi cyane (uburemere bwa 12-18%), bifitanye isano na karubone nyinshi hamwe na nikel nkeya. Ibyuma bitagira umwanda birwanya cyane kwangirika (nubwo ibyo byuma bidashobora kwihanganira ibyuma bifite nikel nyinshi) kuko chromium na nikel bigize okiside ihamye cyane; iyi oxyde ikora firime yo hejuru irinda ibindi bitero.

Ibyuma bitagira umwanda mubisanzwe birimo ibice bya chromium (cyangwa ibindi byuma bivangwa), karbide. Ubu bwoko bwibyuma burazwi kuko bufite ubuzima burebure kurenza ubundi (karbide irakomeye kuruta ibyuma), biragoye gukarisha no kubora hamwe ningorabahizi, ibyuma bito ("karubone") ibyuma (ibice bimwe byubutaka ntibishobora kuba byoroshye ikarishye), nubwo ibizamini byerekana ko ibyuma bitagira umuyonga bifata neza kuruta ibyuma bisanzwe. Ubukomezi nimbaraga zibyuma bidafite ingese bikunda kuba munsi yicyuma kivanze. Ibyuma bitagira umuyonga na kimwe cya kabiri kirimo D2, S30V, 154CM, ATS-34, na 440C.

Ubwoko bwiza bwibyuma bidasanzwe birashobora gukoreshwa mugukora ibyuma; ibindi bikoresho birashobora gukoreshwa, nubwo ibi bitamenyerewe cyane kuruta ibyuma. Abakora ibyuma nka Spyderco na Benchmade bakunze gukoresha 154CM, VG-10, S30V na CPM440V (izwi kandi nka S60V), hamwe n’umuvuduko mwinshi n’ibikoresho bikomeye nka D2 na M2. Abandi bakora rimwe na rimwe bakoresha titanium, cobalt na cobalt. Byose uko ari bitatu birahindagurika kuruta ibyuma bisanzwe bidafite ingese, ariko bifite itsinda rinini ryabashyigikiye nubwo bahangayikishijwe ningaruka zubuzima bwa cobalt. Ubuhanzi bwumwimerere bwo guhimba ibyuma bya Damasiko birashobora gutakara, ariko ntibibe ikirangantego cyanditse, ubu izina ryakoreshejwe mubyerekeranye nubusaza buke ariko butari buke bwibikoresho bipfunyika, bikora ibishushanyo mbonera. Igiciro cyibikorwa bigabanya imikoreshereze yicyuma cyegeranijwe. Mubisanzwe harakenewe cyane amavuta avanze mubyiciro byingirakamaro, umufuka cyangwa kurwanira ibyuma kuruta uko biri mubyiciro byicyuma cyigikoni.

Vanadium na molybdenum nibyingenzi bivanga ibyuma, kuko bituma ingano yintete iba nto, bityo bikongerera imbaraga nimbaraga. Vanadium, ndetse wenda na molybdenum, nayo yongera imbaraga zo kurwanya ruswa, nubwo ubushakashatsi bwakozwe na CATRA (ishyirahamwe ry’ubushakashatsi ryashinzwe n’inganda zimwe na zimwe zivanze n’ibiti) nta ngaruka zigeze zirwanya ruswa.

Ibikoresho byihariye 
Bamwe mubakora nka Kyocera bakora ibyuma byububiko bwicyuma cyigikoni; ibi byuma birangwa no gukomera gukomeye no kurwanya gukata. Nyamara, ibikoresho biroroshye kandi birashobora gukata no kumeneka byoroshye. Kubera iyo mpamvu, ntibisabwa koza mumashini yoza ibikoresho.

Okiside ya Zirconium ikoreshwa nkibikoresho byubutaka kandi iracumura kugirango ibone ishusho yifuza.

No muri iki gihe, ibyuma bipakira ibyuma, byitwa na damascus, biri ku isoko, aho bikozwe mu mwenda w'imbere kugira ngo bigaragare, kugira ngo hubakwe ibyuma byiza. Nicyuma gikoreshwa kuva 1000 AD. n'abakora ibyuma bikomeye mubwoko buzwi cyane ni katana yUbuyapani, yahimbwe mubyuma byera tamahagane byakozwe nitanura rimwe mubuyapani hanyuma bigabanywa kubacuzi batandukanye.

Ihuza ryo hanze 

 (IT) Coltello, marchio italiano, Il-Coltello, , Inc. Hindura kuri Wikidata
 (EN) Icyuma, kuva muri Encyclopedia Britannica, Encyclopædia Britannica, Inc. Hindura kuri Wikidata