Design and preparation of low-cost α plus β titanium alloy based on assessment of Ti-Al-Fe-Cr system

作者：Wang, Jing; Qin, Ziwei; Xiong, Fuhao; Wang, Shusen; Lu, Xionggang; Li, Chonghe^*

来源：Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 2018, 732: 63-69.

DOI：10.1016/j.msea.2018.06.101

• Ti-Al-Fe-Cr system
• Pseudobinary sections
• Ti-3Al-8.5Cr-2Fe alloy
• Laves C14
• Mechanical properties

Previous investigations of the Ti-Al-Fe-Cr quaternary system and its related sub-systems were reviewed and summarized, then the thermodynamical database of the Ti-Al-Fe-Cr quaternary system was built up by directly extrapolating from the four sub-ternary systems using the Calphad method. The pseudobinary sections with Cr: Fe = 5.2:1 and Al = 0.0, 3.0, 4.5 and 6.0 wt% were calculated, combined with the empirical design criterion including aluminum and molybdenum equivalent, a novel alpha + beta type titanium alloy Ti-3Al-8.5Cr-2Fe was proposed and successfully prepared. Microscopic observation showed that Ti-3Al-8.5Cr-2Fe contained alpha and beta phase which was consistent with expectation, no segregation of the elements Cr and Fe existed in grain boundaries and CIA laves phase was not detected in Ti-3Al-8.5Cr-2Fe alloy. Mechanical properties were investigated using the universal testing machine and results showed that the average ultimate tensile strength (sigma(b)), 0.2% proof strength (sigma(0.2)) and elongation (EI) of this alloy in thermo-mechanical state can reach 985 MPa, 904.5 MPa and 19.6 Pct, respectively, which is similar to the Ti-4.3Fe-7.1Cr- 3.0Al(TFCA) and Ti-3Al-5Mo-4.5V (TC16). The SEM photographs of fracture surface showed that the fracture of Ti-3Al-8.5Cr-2Fe sheets after quenching process is plastic fracture.

• 出版日期2018-8-8
• 单位上海大学