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Processing and Microstructures of Cr-Ta and Cr-Ta-Mo Composites Reinforced By the Cr(sub 2) Laves Phase.

DE2005835705

Publication Date	2005
Personal Author	Wang, D. F.; Liaw, P. K.; Liu, C. T.; George, E. P.
Page Count	12
Abstract	The Cr-Ta alloy with an eutectic structure has a good combination of high strength and oxidation resistance at elevated temperatures up to 1,200 C. It is an ideal candidate for ultrahigh-temperature applications. However, the material shows low ductility and fracture toughness at room temperature. An effective way to improve the ductility and fracture toughness is to obtain an aligned microstructure of eutectic Cr-based alloys, using a directional-solidification (DS) process, in which the feed materials with eutectic compositions are preferred. In the present work, a quantitative technique was employed to assist in monitoring and controlling the composition of the Cr-based alloys throughout the processing stages at elevated temperatures. A colony structure related to the instable liquid/solid interface was observed in a DS Cr-Ta sample. A possible eutectic area was probed in the Cr-Mo-Ta system, which could facilitate the development of well-aligned lamellar structures by DS.
Keywords	Alloys Ductility Fracture properties Monitoring Oxidation Laves phases
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Oak Ridge National Lab., TN. Metals and Ceramics Div.; Tennessee Univ., Knoxville. Dept. of Materials Science and Engineering.; Department of Energy, Washington, DC.
Supplemental Notes	Prepared in cooperation with Tennessee Univ., Knoxville. Dept. of Materials Science and Engineering. Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200524

Processing and Microstructures of Cr-Ta and Cr-Ta-Mo Composites Reinforced By the Cr(sub 2) Laves Phase.

Processing and Microstructures of Cr-Ta and Cr-Ta-Mo Composites Reinforced By the Cr(sub 2) Laves Phase.
DE2005835705

Publication Date	2005
Personal Author	Wang, D. F.; Liaw, P. K.; Liu, C. T.; George, E. P.
Page Count	12
Abstract	The Cr-Ta alloy with an eutectic structure has a good combination of high strength and oxidation resistance at elevated temperatures up to 1,200 C. It is an ideal candidate for ultrahigh-temperature applications. However, the material shows low ductility and fracture toughness at room temperature. An effective way to improve the ductility and fracture toughness is to obtain an aligned microstructure of eutectic Cr-based alloys, using a directional-solidification (DS) process, in which the feed materials with eutectic compositions are preferred. In the present work, a quantitative technique was employed to assist in monitoring and controlling the composition of the Cr-based alloys throughout the processing stages at elevated temperatures. A colony structure related to the instable liquid/solid interface was observed in a DS Cr-Ta sample. A possible eutectic area was probed in the Cr-Mo-Ta system, which could facilitate the development of well-aligned lamellar structures by DS.
Keywords	Alloys Ductility Fracture properties Monitoring Oxidation Laves phases
Source Agency	Technical Information Center Oak Ridge Tennessee
Corporate Authors	Oak Ridge National Lab., TN. Metals and Ceramics Div.; Tennessee Univ., Knoxville. Dept. of Materials Science and Engineering.; Department of Energy, Washington, DC.
Supplemental Notes	Prepared in cooperation with Tennessee Univ., Knoxville. Dept. of Materials Science and Engineering. Sponsored by Department of Energy, Washington, DC.
Document Type	Technical Report
NTIS Issue Number	200524