Effect of low temperature thermo-mechanical treatment on microstructures and mechanical properties o

• 作 者: SUN Li-ping LIN Gao-yong LIU Jian ZENG Ju-hua
• 机 构: School of Materials Science and Engineering, Central South University, Changsha 410083, China;Key La
• 出 处: 中南大学学报（英文版）
• 发表日期: 2010年3期
• 关键词: Ti-6Al-4V (TC4) alloy low temperature thermo-mechanical treatment microstructure

The effects of low temperature thermo-mechanical treatment (LTTMT) on microstructures and mechanical properties of Ti-6Al-4V (TC4) alloy were studied by optical microscopy (OM), tensile test, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The experimental results confirm that the strength of TC4 alloy can be improved obviously by LTTMT processing, which combines strain strengthening with aging strengthening. The effect of LTTMT on the alloy depends on the microstructure of the refined and dispersed α+β phase on the basis of high dislocation density by pre-deformation below recrystallization temperature. The tensile strength decreases with the increase of pre-deformation reduction. The optimal processing parameters of LTTMT for TC4 alloy are as follows:solution treatment at 900 ℃ for 15 min, pre-deformation in the range of 600-700 ℃ with a reduction of 35%, finally aging at 540 ℃ for 4 h followed by air-cooling.