Injet muab cov txheej txheem ua tiav ntawm cov kev daws teeb meem siab tshaj plaws rau cov hlau thiab hlau metallurgy kev lag luam, muab cov khoom siv hluav taws xob zoo, huv si thiab cov khoom siv hluav taws xob zoo thiab cov kev pabcuam rau ntau cov hlau thiab hlau loj, thiab pab txhawb rau kev hloov pauv, kho dua tshiab thiab txhim kho kom ruaj khov. hlau thiab hlau metallurgy kev lag luam.