Processing and Characterizing RuAl Eutectics

2002 ◽  
Vol 753 ◽  
Author(s):  
Todd Reynolds ◽  
David Johnson
Keyword(s):  
Solid Solution ◽  
Liquidus Projection ◽  
Cold Crucible ◽  
Eutectic Alloys ◽  
Czochralski Technique ◽  
Hardness Testing ◽  
Directionally Solidified ◽  
Partial Liquidus Projection ◽  
Solidification Microstructures ◽  
Hardness Values

ABSTRACTEutectic alloys in the Ru-Al-Mo system were directionally solidified by a cold crucible Czochralski technique. The solidification microstructures and composition of the phases were examined and used to estimate a partial liquidus projection. Preliminary results from compression and hardness testing indicate that the hardness of RuAl varies significantly with composition. The Ru-rich alloys in which RuAl is in equilibrium with the hcp (Ru,Mo) solid solution were found to have the lowest hardness values.

Ti-Modified Niobium-Silicide Based Directionally Solidified in-situ Composites

1996 ◽  
Vol 460 ◽  
Author(s):  
B. P. Bewlay ◽  
M. R. Jackson ◽  
H. A. Lipsitt
Keyword(s):  
Solid Solution ◽  
Fracture Toughness ◽  
High Temperature ◽  
Cold Crucible ◽  
Directionally Solidified ◽  
In Situ Composites ◽  
Czochralski Crystal Growth ◽  
Three Phase ◽  
Binary Eutectic

ABSTRACTThis paper examines microstructure-property relationships in high-temperature directionally solidified (DS) in-situ composites based on Nb silicides, such as Nb3Si and Nb5Si3. These in-situ composites are based on the Nb3Si-Nb binary eutectic, and are alloyed with Ti. They were prepared using cold crucible Czochralski crystal growth. Ternary Nb-Ti-Si alloys with Ti concentrations from 9 to 45%, and Si concentrations from 10 to 25%, were directionally solidified to generate aligned two- and three-phase composites containing a Nb solid solution with Nb3Si and Nb5Si3 silicides. Fracture toughness values generally greater than 10 MPa√m were measured in these composites. For a given Si concentration, the fracture toughness of the Ti-containing composites was increased ∼ 6 MPa√m over that of the binary alloy composites. The effects of Si concentration, and a range of Nb:Ti ratios, on microstructure, phase equilibria, and fracture toughness were examined.

Nanoscratching meets nanoindentation

2016 ◽  
Vol 231 (6) ◽  
Author(s):  
Irina P. Shakhverdova ◽  
Marianne Reibold ◽  
Werner Kochmann ◽  
Peter Paufler
Keyword(s):  
Normal Load ◽  
Adhesion Forces ◽  
Hardness Testing ◽  
Ambient Conditions ◽  
High Carbon ◽  
Surface Layers ◽  
Significant Drop ◽  
Nano Structures ◽  
Scratch Tests ◽  
Hardness Values

AbstractA specimen of high-carbon nitrogen-doped steel has been synthesized to supplement previous studies on wootz-like steels. A comparison of different states of material as well as one of distinct methods of hardness testing has been performed. Electron microscopy of the specimens’ microstructure revealed nano-structuring similar to that observed with ancient sabers. Part of them was annealed so that the nano-structures dissolved. Nano-hardness values derived under ambient conditions from indentation as well as from scratch tests were determined and related to the microstructure prior to and after annealing. The disappearance of nanostructuring led to a significant drop of hardness. The ratio of indentation to scratch hardness proved a suitable indicator of hardening. From hardness as function of penetration depth and from friction as function of time and normal load various quantitative features of the mechanical properties and of the deformation process have been evaluated. When modeling friction, sliding and plowing parts have been distinguished quantitatively. Enhanced adhesion forces were attributed to surface layers.

Heat transfer and macrostructure formation of Nb containing TiAl alloy directionally solidified by square cold crucible

2013 ◽  
Vol 42 ◽  
pp. 184-191 ◽  
Author(s):  
Jieren Yang ◽  
Ruirun Chen ◽  
Hongsheng Ding ◽  
Jingjie Guo ◽  
Jiecai Han ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Tial Alloy ◽  
Cold Crucible ◽  
Directionally Solidified

The morphology and crystallography of directionally solidified pb-sn eutectic alloys

1977 ◽  
Vol 8 (8) ◽  
pp. 1239-1247 ◽  
Author(s):  
J. D. Verhoeven ◽  
E. D. Gibson ◽  
D. P. Mourer
Keyword(s):  
Eutectic Alloys ◽  
Directionally Solidified
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