Microstructure and Room-Temperature Fracture Toughness of Nb–Ti–Si In Situ Composite Prepared by Selective Laser Melting

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.

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Effect of W Alloying and NbC Dispersion on High Temperature Strength at 1773 K and Room Temperature Fracture Toughness in Nb5Si3/Nb In-situ Composites

MATERIALS TRANSACTIONS ◽

10.2320/matertrans.43.1415 ◽

2002 ◽

Vol 43 (6) ◽

pp. 1415-1418 ◽

Cited By ~ 12

Author(s):

Won-Yong Kim ◽

Hisao Tanaka ◽

Shuji Hanada

Keyword(s):

Fracture Toughness ◽

High Temperature ◽

Room Temperature ◽

High Temperature Strength ◽

Temperature Fracture

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Effect of Mo Addition on Microstructure and Properties of Nb/Nb5Si3 In-Situ Composite

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.753 ◽

2004 ◽

Vol 449-452 ◽

pp. 753-756 ◽

Cited By ~ 2

Author(s):

Wei Li ◽

Hai Bo Yang ◽

Ai Dang Shan ◽

Jian Sheng Wu

Keyword(s):

Fracture Toughness ◽

Room Temperature ◽

Metastable Phase ◽

High Strength ◽

High Fracture Toughness ◽

High Fracture ◽

Ductile Phase ◽

Temperature Fracture ◽

The Stability

Nb/Nb5Si3 in-situ composites are very attractive structural materials for these materials perform a good balance in mechanical properties, including a high strength at high temperature (>1373K) and reasonably high fracture toughness at room temperature. Metastable phase Nb3Si plays an important role in the properties of Nb/Nb5Si3 composites by affecting microstructure and volume fracture of ductile phase. In this paper, Nb-10Si-xMo and Nb-18Si-xMo (x=0,5,15) are prepared by arc melting and annealed at 1473K for 100h. Single edge-notched bending (SENB) test was used to study the fracture toughness of Nb-Si-Mo alloys. The stability of metastable phase is analyzed by XRD. The room temperature fracture toughness of Nb-10Si is 10.47MPa(m)1/2 and higher than that of binary Nb-18Si alloys at near-eutectic compositions. The addition of Mo improves the fracture toughness of as cast Nb-Si alloys from 4.1 MPa(m)1/2 to 9.9MPa(m)1/2 at near-eutectic compositions and decreases it from 10.47 MPa(m)1/2 to 8.8MPa(m)1/2 at hypoeutectic compositions.

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High-temperature Strength and Room-temperature Fracture Toughness of Mo-ZrC in-situ Composites with Hyper-eutectic Structure

Journal of the Japan Institute of Metals and Materials ◽

10.2320/jinstmet1952.64.11_1082 ◽

2000 ◽

Vol 64 (11) ◽

pp. 1082-1088 ◽

Cited By ~ 8

Author(s):

Teppei Suzuki ◽

Naoyuki Nomura ◽

Kyosuke Yoshimi ◽

Shuji Hanada

Keyword(s):

Fracture Toughness ◽

High Temperature ◽

Room Temperature ◽

Eutectic Structure ◽

High Temperature Strength ◽

Temperature Fracture

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.306-308.941 ◽

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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