Ti-600合金蠕变性能及硅对其蠕变性能的影响

研究了Ti-600合金在3种温度(550、600、650℃)、5种应力(150、200、250、300、350 MPa)下的蠕变性能,并分析了硅化物对合金蠕变性能的影响。研究结果表明,Ti-600合金具有较小的稳态蠕变速率及较大的蠕变激活能,反映出该合金具有较好的蠕变抗力。当温度升高、应力增大时,Ti-600合金的稳态蠕变速率增大。600℃下,当蠕变应力高达350 MPa时,Ti-600合金的稳态蠕变速率低至3.72×10-7s-1。Ti-600合金的蠕变激活能最高可达574.6kJ·mol-1,最低为332.7 kJ·mol-1。在蠕变过程中,Ti-600合金内析出了S2型(TiZr)6Si3硅化物,能够钉扎位错、阻碍位错滑移,提高合金的蠕变抗力。

Creep Property and Influence of Silicide on the Creep Property for Ti-600 Alloy

Creep tests were carried out on Ti-600 alloy at the temperature of 550 ℃, 600 ℃, 650 ℃, and with the stress of 150 MPa, 200 MPa, 250 MPa, 300 MPa and 350 MPa, respectively.Creep property of Ti-600 alloy and in-fluence of silicide on the creep property for the alloy were also investigated .The results indicated that the value of steady state creep rate is small , and the activation energy is relatively high , which means the alloy possesses favorite creep resistance .The steady state creep rate will increase with the increment of temperature and stress during the creep process.And the steady state creep rate is as low as 3.72 ×10 ^-7 s^-1 for the alloy creep at 600 ℃with the stress of 350 MPa.The calculated highest creep activation energy for the alloy is 574.6 kJ· mol^ -1 , and the lowest one is 332.7 kJ· mol^ -1 .During the creep process , slip would be impeded , and dislocations would also be pinned by the pre-cipitated S2 typed silicides （（TiZr）6Si3）, then the motion of dislocations would be hindered , which has contribution to the higher creep resistance , and the higher values of activation energy .