Feem ntau siv nyob rau hauv daim ntawv thov uas yuav tsum tau siab thermal lossis hluav taws xob conductivity.Cov hlau muaj lub zog zoo thiab cov yam ntxwv hardness ua ke nrog kev ua haujlwm ntawm 45-60 feem pua ntawm cov tooj liab nrog qhov kawg tensile thiab hardness zog nce mus txog 140 ksi thiab RB 100 feem.