Microstructure and room temperature deformation of Nbss/Nb5Si3 in situ composites alloyed with Mo

2001 ◽  
Vol 9 (6) ◽  
pp. 521-527 ◽  
Author(s):  
Won-Yong Kim ◽  
Hisao Tanaka ◽  
Akio Kasama ◽  
Ryohei Tanaka ◽  
Shuji Hanada
Keyword(s):  
Room Temperature ◽  
Temperature Deformation ◽  
In Situ Composites

Mechanical properties of NiAl-Mo composites produced by specially controlled directional solidification

2012 ◽  
Vol 1516 ◽  
pp. 255-260 ◽  
Author(s):  
G. Zhang ◽  
L. Hu ◽  
W. Hu ◽  
G. Gottstein ◽  
S. Bogner ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Directional Solidification ◽  
Creep Resistance ◽  
Room Temperature ◽  
Growth Direction ◽  
Nominal Composition ◽  
Potential Candidate ◽  
In Situ Composites

ABSTRACTMo fiber reinforced NiAl in-situ composites with a nominal composition Ni-43.8Al-9.5Mo (at.%) were produced by specially controlled directional solidification (DS) using a laboratory-scale Bridgman furnace equipped with a liquid metal cooling (LMC) device. In these composites, single crystalline Mo fibers were precipitated out through eutectic reaction and aligned parallel to the growth direction of the ingot. Mechanical properties, i.e. the creep resistance at high temperatures (HT, between 900 °C and 1200 °C) and the fracture toughness at room temperature (RT) of in-situ NiAl-Mo composites, were characterized by tensile creep (along the growth direction) and flexure (four-point bending, vertical to the growth direction) tests, respectively. In the current study, a steady creep rate of 10-6s-1 at 1100 °C under an initial applied tensile stress of 150MPa was measured. The flexure tests sustained a fracture toughness of 14.5 MPa·m1/2at room temperature. Compared to binary NiAl and other NiAl alloys, these properties showed a remarkably improvement in creep resistance at HT and fracture toughness at RT that makes this composite a potential candidate material for structural application at the temperatures above 1000 °C. The mechanisms responsible for the improvement of the mechanical properties in NiAl-Mo in-situ composites were discussed based on the investigation results.

Microscopic study of the room temperature deformation mechanisms in β+γ' – (70 at.% Ni −30 at.% Al) in situ composite

1992 ◽  
Vol 50 (1) ◽  
pp. 912-913
Author(s):  
A. Misra ◽  
R. Gibala
Keyword(s):  
Microscopic Study ◽  
Room Temperature ◽  
Temperature Deformation ◽  
Nominal Composition ◽  
Second Phase ◽  
Directionally Solidified ◽  
Ductile Phase ◽  
Two Phase ◽  
Room Temperature Ductility

Ductile phase reinforcement is an attractive approach for enhancing the room temperature ductility and toughness of brittle intermetallics such as β−NiAl. For example, a directionally solidified alloy of nominal composition 70 at.% Ni −30 at.% Al, having a two-phase β (brittle matrix) and γ (ductile second phase) microstructure, exhibits up to 9% tensile ductility at room temperature [1]. In the present investigation, a microscopic study has been made to understand the mechanisms involved in the ductility enhancement of the β + γ composite.

Room Temperature Deformation Mechanisms of Alumina Particles Observed from In Situ Micro-compression and Atomistic Simulations

2015 ◽  
Vol 25 (1-2) ◽  
pp. 82-93 ◽  
Author(s):  
Pylin Sarobol ◽  
Michael Chandross ◽  
Jay D. Carroll ◽  
William M. Mook ◽  
Daniel C. Bufford ◽  
...  
Keyword(s):  
Room Temperature ◽  
Deformation Mechanisms ◽  
Atomistic Simulations ◽  
Temperature Deformation ◽  
Alumina Particles

Microstructure and room temperature fracture toughness of Nbss/Nb5Si3 in situ composites

2001 ◽  
Vol 9 (9) ◽  
pp. 827-834 ◽  
Author(s):  
Won-Yong Kim ◽  
Hisao Tanaka ◽  
Akio Kasama ◽  
Shuji Hanada
Keyword(s):  
Fracture Toughness ◽  
Room Temperature ◽  
In Situ Composites ◽  
Temperature Fracture

scholarly journals Deformation of Mg-γMg17Al12 in situ composites: Room temperature mechanical behaviour, microstructures and mechanisms

2021 ◽  
Vol 132 ◽  
pp. 107127
Author(s):  
Patricia Donnadieu ◽  
Souad Benrhaiem ◽  
Gilles Renou ◽  
Chunyang Zhang ◽  
Catherine Tassin ◽  
...  
Keyword(s):  
Mechanical Behaviour ◽  
Room Temperature ◽  
In Situ Composites

Microstructures and Properties of Ds in-Situ Composites of Nb-Ti-Si Alloys

1994 ◽  
Vol 364 ◽  
Author(s):  
B. P. Bewlay ◽  
M. R. Jackson ◽  
W. J. Reeder ◽  
H. A. Lipsitt
Keyword(s):  
Mechanical Properties ◽  
Solid Solution ◽  
Fracture Toughness ◽  
Room Temperature ◽  
In Situ Composites ◽  
Environmental Resistance ◽  
High Temperature Mechanical Properties ◽  
Three Phase ◽  
Temperature Fracture

AbstractIn-situ composites based on binary Nb-Si alloys and consisting of a Nb solid solution with Nb3Si or Nb5Si3 have shown a promising combination of low temperature and high temperature mechanical properties. The environmental resistance and room temperature fracture toughness of these composites can be further enhanced by additions such as Ti, Hf, Cr, and Al. In the present study, ternary Nb-Ti-Si alloys were prepared by directional solidification to generate aligned two and three phase composites containing a Nb solid solution with Nb3Si and/or Nb5Si3. The present paper will describe microstructures, phase equilibria and fracture toughness of these composites. The improvement in the room temperature fracture toughness over binary Nb-Nb5Si3 composites is discussed.

Enhanced plasticity in a Ti-based bulk metallic glass-forming alloy by in situ formation of a composite microstructure

2002 ◽  
Vol 17 (12) ◽  
pp. 3015-3018 ◽  
Author(s):  
G. He ◽  
W. Löser ◽  
J. Eckert ◽  
L. Schultz
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Room Temperature ◽  
Shear Bands ◽  
Temperature Deformation ◽  
Glassy Matrix ◽  
Glass Forming ◽  
Injection Casting ◽  
Composite Microstructure

A bulk metallic glass-forming Ti–Cu–Ni–Sn alloy with in situ formed composite microstructure prepared by both centrifugal and injection casting presents more than 6% plastic strain under compressive stress at room temperature. The in situ formed composite contains dendritic hexagonal-close-packed-Ti solid solution precipitates and a few Ti3Sn, β –(Cu, Sn) grains dispersed in a glassy matrix. The composite microstructure can avoid the development of the highly localized shear bands typical for the room-temperature deformation of monolithic glasses. Instead, highly developed shear bands with evident protuberance are observed, resulting in significant yielding and homogeneous plastic deformation over the entire sample.

Tensile and Fracture Behavior of NbSS/Nb5Si3 In Situ Composites Prepared by Arc Melting

2005 ◽  
Vol 297-300 ◽  
pp. 507-514
Author(s):  
Jin Hak Kim ◽  
Tatsuo Tabaru ◽  
Michiru Sakamoto ◽  
Shuji Hanada
Keyword(s):  
Base Composition ◽  
Fracture Behavior ◽  
Room Temperature ◽  
Secondary Phase ◽  
Secondary Phases ◽  
In Situ Composites ◽  
Arc Melting ◽  
Negative Effect ◽  
Base Composite

Nb-base in-situ composites, which have the base composition of Nb-18Si-5Mo-5Hf, have been investigated in microstructure, hardness (Hv*), Young’s modulus (E), tensile properties and fracture behavior. The microstructures of all composites examined consist of NbSS matrix and Nb5Si3 secondary phases. No secondary phase such as Nb2C appeared. The crystal structure of Nb5Si3 is Mn5Si3-type when C replaces 2mol%-Nb, though typical structures of a (Cr5B3-type) and b (W5Si3-type) as in the base composition when W replaces. W addition is effective in increasing Hv* and E of both phases as expected. However, C alloying is somewhat beneficial only in Nb5Si3 with a noticeable negative effect in NbSS. Furthermore, the composite exhibits the highest strength at 1473 K, while the base composite exhibits the highest at room temperature. The fracture behavior is independent of the compositions and it is controlled by cleavage fractures of Nb5Si3, decohesion of NbSS/Nb5Si3 interface and ductile rupture of NbSS depending on the testing temperatures.

Effects of Re Alloying on Mechanical Properties of In-Situ Composites with Base Composition of Nb-18Si-2HfC

2006 ◽  
Vol 306-308 ◽  
pp. 941-946
Author(s):  
Sheng Wu Wang ◽  
Tatsuo Tabaru ◽  
Hisatoshi Hirai ◽  
Hideto Ueno
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Base Composition ◽  
Room Temperature ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
In Situ Composites ◽  
Temperature Fracture

Nb-base in-situ composites with the base composition of Nb-18Si-2HfC were prepared by conventional arc-melting. Their microstructures and mechanical properties, such as high-temperature strength and room temperature fracture toughness, were investigated to elucidate the effects of Re alloying. The in-situ composites predominantly have eutectic microstructures consisting of an Nb solid solution (NbSS) and Nb5Si3. The compressive strength increased with the increasing Re contents at 1470K and not at 1670 K. The strengthening effect observed at 1470 K is higher than that by W and Mo. Re alloying of about 2 % is valuable for improving both the high temperature strength and room temperature fracture toughness of Nb-18Si-2HfC base materials.

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