4J42ndi aloyi yokhazikika yokhazikika yachitsulo-nickel, yomwe imapangidwa makamaka ndi chitsulo (Fe) ndi nickel (Ni), yokhala ndi nickel pafupifupi 41% mpaka 42%. Kuphatikiza apo, ilinso ndi zinthu zochepa monga silicon (Si), manganese (Mn), kaboni (C), ndi phosphorous (P). Kapangidwe kake kapadera ka chemica kamapangitsa kuti igwire bwino ntchito.

Kumayambiriro kwa zaka za m'ma 1900, chifukwa cha kukwera kwa ukadaulo wamagetsi, ndege ndi madera ena, zofunikira zapamwamba zidaperekedwa pakukula kwa kutentha ndi mawonekedwe a makina a zinthu, ndipo ofufuza adayamba kufufuza zinthu za aloyi zokhala ndi mawonekedwe enaake. Monga aloyi yachitsulo-nickel-cobalt, kafukufuku ndi chitukuko cha aloyi yowonjezera ya 4J42 cholinga chake ndi kukwaniritsa zosowa za madera awa kuti zinthu zigwire bwino ntchito. Mwa kusintha mosalekeza zomwe zili muzinthu monga nickel, chitsulo, ndi cobalt, kuchuluka kwa kapangidwe ka 4J42 aloyi kwadziwika pang'onopang'ono, ndipo anthu ayambanso kupeza ntchito zoyambirira m'magawo ena omwe ali ndi zofunikira kwambiri pakugwira ntchito kwazinthu.

Ndi kupita patsogolo kosalekeza kwa sayansi ndi ukadaulo, zofunikira pakugwira ntchito kwa aloyi yowonjezera ya 4J42 zikukulirakulira. Ofufuza akupitilizabe kukonza magwiridwe antchito a aloyi ya 4J42 mwa kukonza njira zopangira ndikukonza kapangidwe ka aloyi. Mwachitsanzo, kugwiritsa ntchito ukadaulo wapamwamba kwambiri wosungunulira ndi ukadaulo wokonza kwawongolera kuyera ndi kufanana kwa aloyi, ndikuchepetsa kwambiri momwe zinthu zodetsedwa zimakhudzira magwiridwe antchito a aloyi. Nthawi yomweyo, njira yochizira kutentha ndi njira yowotcherera ya aloyi ya 4J42 yaphunziridwanso mozama, ndipo magawo ambiri asayansi komanso oyenera apangidwa kuti akonze magwiridwe antchito ndikugwiritsa ntchito aloyi.

M'zaka zaposachedwa, chifukwa cha kukula kwachangu kwa zamagetsi, ndege, zamankhwala ndi zina, kufunikira kwa aloyi yowonjezera ya 4J42 kwapitirira kukwera, ndipo gawo logwiritsira ntchito lapitirira kukulirakulira. M'munda wa zamagetsi, chifukwa cha chitukuko chopitilira cha ma circuits ophatikizika, zida za semiconductor, ndi zina zotero, zofunikira pazipangizo zopakira zikukwera kwambiri. Aloyi ya 4J42 yakhala chinthu chofunikira kwambiri pakupanga ma CD amagetsi chifukwa cha magwiridwe antchito ake abwino pakukulitsa kutentha komanso magwiridwe antchito a welding.

Ndi kupita patsogolo kosalekeza kwa ukadaulo wopanga, chisamaliro chachikulu chidzaperekedwa pakukweza chiyero cha aloyi ndikuchepetsa kuchuluka kwa zinthu zodetsedwa mtsogolo. Izi zipititsa patsogolo kukhazikika kwa magwiridwe antchito a aloyi, kuchepetsa kusinthasintha kwa magwiridwe antchito komwe kumachitika chifukwa cha zinyalala, ndikuwonjezera kudalirika kwa aloyi pakugwiritsa ntchito molondola kwambiri. Mwachitsanzo, pankhani yolongedza zamagetsi, aloyi ya 4J42 yoyera kwambiri imatha kutsimikizira kukhazikika kwa nthawi yayitali komanso magwiridwe antchito apamwamba a zida zamagetsi.