Development of quaternary Ir-Ta-Ni-Al refractory superalloys

Journal Article · Fri Aug 20 04:00:00 EDT 1999 · Scripta Materialia

DOI:https://doi.org/10.1016/S1359-6462(99)00112-8· OSTI ID:691323

Yu, Xihong; Yamabe-Mitarai, Yoko; Ro, Yoshikazu; Gu, Yuefeng; Harada, Hiroshi ^[1]

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1. National Research Inst. for Metals, Tsukuba, Ibaraki (Japan)

To improve the performance of Ir-based alloys, the authors propose alloys designed by combining Ir- and Ni-based alloys because Ni-based alloys are ductile, have a relatively low density (about 8.5g/cm{sup 3}, compared to 22g/cm{sup 3} for Ir), and low cost. The objective is to combine the high-temperature strength of Ir-based alloys with the good ductility, low density, and low cost of Ni-based alloys. If the fcc and L1{sub 2} phases with coherent structure form in both alloys, the authors expect that the fcc and L1{sub 2} two-phase regions of the Ir- and Ni-based alloys will connect with each other at the interface of the Ir-based and Ni-based alloys. The coherency of the fcc/L1{sub 2} phase is very important for quaternary alloys to achieve high strength at high temperature. The authors chose the Ir-Ta alloy from the available Ir-based binary alloys because the strength of the Ir-Ta binary alloy is high at high temperature (over 700 MPa at 1,200 C) and because Ta has a solid solution hardening effect in Ni-based alloys. For the Ni alloy, they chose the Ni-Al alloy because it is of coherent structure of fcc and L1{sub 2}. They therefore studied the strength and microstructure of Ir-Ta-Ni-Al quaternary alloys.

• OSTI ID: 691323
• Journal Information: Scripta Materialia, Journal Name: Scripta Materialia Journal Issue: 6 Vol. 41; ISSN 1359-6462; ISSN SCMAF7
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
COMPRESSION STRENGTH
CONCENTRATION RATIO
DENDRITES
IRIDIUM ALLOYS
MICROSTRUCTURE
NICKEL ALLOYS
PHASE DIAGRAMS
TANTALUM ALLOYS