Effect of Re on the Microstructure and Mechanical Properties of NbTiZr and TaTiZr Equiatomic Alloys

Metals

Daniel B. Miracle¹  Oleg N. Senkov¹  Eric J. Payton¹  Robert Wheeler¹  Stéphane Gorsse² 

[1] Air Force Research Laboratory, Materials and Manufacturing Directorate, Wright-Patterson AFB, Dayton, OH 45433, USA;CNRS, Univ. Bordeaux, Bordeaux INP, ICMCB, UMR 5026, F-33600 Pessac, France;

关键词: refractory alloy;    microstructure;    phase composition;    CALPHAD;    mechanical properties;   

DOI  :  10.3390/met11111819

来源: DOAJ

【 摘 要 】

The microstructure, phase composition, and mechanical properties of NbTiZr, TaTiZr, Re_0.3NbTiZr, and Re_0.3TaTiZr are reported. The alloys were produced by vacuum arc melting and hot isostatically pressed (HIP’d) at 1400 °C for 3 h under 276 MPa hydrostatic pressure of high-purity argon prior to testing. NbTiZr had a single-phase BCC crystal structure, while TaTiZr had a Ti- and Zr-rich BCC matrix phase and Ta-rich nanometer-sized BCC precipitates, at volume fractions of 0.49 and 0.51, respectively. Re_0.3NbTiZr consisted of a BCC matrix phase and Re-rich precipitates with a FCC crystal structure and the volume fraction of 0.14. The microstructure of Re_0.3TaTiZr consisted of a Zr-rich BCC matrix phase and coarse, Re and Ta rich, BCC particles, which volume fraction was 0.47. NbTiZr and TaTiZr had a room temperature (RT) yield stress of 920 MPa and 1670 MPa, respectively. While, 10 at.% Re additions increased the RT yield stress to 1220 MPa in Re_0.3NbTiZr and 1715 MPa in Re_0.3TaTiZr. Re also considerably improved the RT ductility of TaTiZr, from about 2.5% to 10% of true strain. The positive strengthening effect from the Re additions was retained at high (800–1200 °C) temperatures.

【 授权许可】

Unknown