近α型、(α+β)型和近β型钛合金的高温力学性能

研究了近α型TA15和Ti60、(α＋β)型TC21和近β型TB17钛合金在100、400、500、600、650和700 ℃时的高温力学性能。结果表明,温度在100~500 ℃时,TB17合金的高温强度最高,TA15合金的高温强度最低,TC21合金的高温强度高于Ti60合金;当温度超过600 ℃后,TB17合金的高温性能变化幅度最大,强度最低,Ti60合金的变化幅度最小,强度最高,TC21合金的强度介于TA15与Ti60合金之间,并逐渐与TA15合金接近;当温度在100 ℃时,4种合金应变硬化和应变软化作用相当,应力-应变曲线处于较为平衡的状态;当温度在400 ℃时,TB17合金变形以应变软化为主,应力随着应变增加显著降低;当温度在600 ℃时,TC21和TA15合金变形也开始以应变软化为主,但TA15合金应力的下降幅度低于TC21合金;直到温度在650 ℃时,Ti60合金变形才以应变软化为主。

High temperature mechanical properties of near α, (α+β) and near β type titanium alloys

High temperature mechanical properties of near α type TA15 and Ti60, near β type TB17, (α+β) type TC21 titanium alloys at 100, 400, 500, 600, 650 and 700 ℃ were investigated. The results show that when the temperature is in the range of 100-500 ℃, the high temperature strength of TB17 alloy is the highest, and that of the TA15 alloy is the lowest. The high temperature strength of the TC21 alloy is higher than that of the Ti60 alloy. When temperature exceeds 600 ℃, the high temperature properties of the TB17 alloy change significantly, and the high temperature strength is the lowest. While the Ti60 alloy changes the least, and the high temperature strength is the highest. The high temperature strength of the TC21 alloy is between that of the TA15 and Ti60 alloys, and gradually closes to that of TA15 alloy. When the temperature is 100 ℃, the engineering stress-strain curves of the four alloys are in a relatively balanced state because of comparable strain hardening and strain softening effects. When the temperature is 400 ℃, the deformation mechanism of the TB17 alloy is dominated by strain softening, and the stress decreases significantly with the increase of strain. When the temperature is 600 ℃, the deformation mechanism of the TC21 and TA15 alloys is also dominated by strain softening, while the stress drop of the TA15 alloy is lower than that of the TC21 alloy. Until the temperature is 650 ℃, the deformation mechanism of the Ti60 alloy is dominated by strain softening.