Precipitation response and hardening behaviors of Fe-modified Ti5553 alloy  

Fe含量对Ti5553合金α相析出响应与硬化行为的影响（英文）

作　　者：Wen-guang ZHU Pei LI Xun SUN Wei CHEN Hua-lei ZHANG Qiao-yan SUN Bin LIU Lin XIAO Jun SUN 朱文光;李沛;孙逊;陈威;张华磊;孙巧艳;刘彬;肖林;孙军(西安交通大学金属材料强度国家重点实验室,西安710049;西安交通大学前沿科学与技术研究院,西安710049;中南大学粉末冶金国家重点实验室,长沙410083)

机构地区：[1]State Key Laboratory for Mechanical Behavior of Materials, Xi’an Jiaotong University, Xi’an 710049, China [2]Frontier Institute of Science and Technology, Xi’an Jiaotong University, Xi’an 710049, China [3]State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China

出　　处：《Transactions of Nonferrous Metals Society of China》2019年第6期1242-1251,共10页中国有色金属学报（英文版）

基　　金：Projects(51671158,51871176,51621063)supported by the National Natural Science Foundation of China;Project(2014CB644003)supported by the National Basic Research Program of China;Project(PB2018008)supported by the 111 Project 2.0,China;Project(2018JM5098)supported by the Natural Science Basic Research Plan in Shaanxi Province of China

摘　　要：Ti5553-xFe (x=0.4, 1.2, 2.0, wt.%) alloys have been designed and fabricated through BE (blended element) sintering to investigate the effect of Fe-addition on athermal ω-phase transformation, α-phase evolution and age hardening behavior. The results show that the formation of athermal ω-phase is fully suppressed in water-quenched specimens when Fe-addition is up to 2 wt.%. The relevant timescales of α formation during initial stages of aging indicate that incubation time increases with Fe-addition. Further aging results in continuous nucleation and growth of α-phase but finer intragranular α lamellae exhibit in Ti5553-2Fe alloy. In addition, the width and extent of grain boundary α-film increase slightly with incremental Fe-addition, especially in furnace cooling condition. Result of Vickers hardness manifests that Fe-addition leads to a strong hardening effect in both solution and aging treatment. The solid solution strengthening is quantitatively estimated by ab initio calculation based on the Labusch?Nabarro model. The evolution of α-precipitate is rationalized by Gibbs free energy. The prominent hardening effect of Ti5553?2Fe alloy is attributed to both large lattice misfit of β-matrix and fine α-precipitate distribution.利用混合元素烧结法制备含0、0.4、1.2和2.0wt.%Fe的Ti5553合金。研究Fe元素对绝热ω相变、α相析出长大以及时效硬化行为的影响规律。结果表明,2wt.%Fe元素的加入可提高β相的稳定性,抑制绝热ω相析出。随着Fe含量增加,α相析出孕育期变长,尺寸变小。α相沿晶析出倾向增强,尤其是在炉冷时,Ti5553-2Fe合金形成明显的魏氏组织。随后,利用Pandat软件并结合经典动力学理论分析Fe含量对Ti5553合金α相析出长大行为的影响机制。硬度曲线表明,不同Fe含量合金的硬度均随时效时间延长先增加,6h达到峰值后缓慢降低。Ti5553-2Fe合金具有最高的峰值硬度,这是Fe等合金元素点阵错配引起的固溶强化与细小α相析出引起的时效强化共同作用的结果。

关 键 词：Fe-modified Ti5553 alloy α-phase evolution hardening behavior Pandat calculation 

分 类 号：TG146.23[一般工业技术—材料科学与工程]