Effect of Trace Ce and B Additions on the Mechanical Properties of Nb-3Si-22Ti Alloys

2017 ◽  
Vol 898 ◽  
pp. 454-460
Author(s):  
Mei Ling Wu ◽  
Feng Wei Guo ◽  
Ming Li ◽  
Yong Wang Kang ◽  
Ya Fang Han
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Room Temperature ◽  
Arc Melting ◽  
Trace Addition ◽  
B Additions ◽  
Temperature Fracture ◽  
Ultrahigh Temperature ◽  
The Relationship

The Nb-Si system ultrahigh temperature alloys were prepared by vacuum non-consumable arc melting. The influence of micro-alloying elements of B and Ce on the hardness, room-temperature fracture toughness and compressive strength at 1250°C of the Nb-22Ti-3Si alloys was investigated and estimated systematically. The results showed that the hardness of the Nb-22Ti-3Si alloy increased obviously with trace B addition, but decreased slightly with trace Ce addition. The room-temperature fracture toughness of the Nb-22Ti-3Si alloy was degraded by the Ce addition but improved by the trace addition of B. The trace addition of B improved the compressive strength of the alloy at 1250°C. In contrast, the trace Ce addition degraded the compressive strength at 1250°C. The relationship between the microstructure and the mechanical properties was discussed.

EFFECT OF VACUUM INDUCTION MELTING TECHNOLOGY ON MECHANICAL PROPERTIES OF Nb-16Si-22Ti-2Al-2Hf-17Cr ALLOY

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2940-2945 ◽  
Author(s):  
XIAOJIAN LI ◽  
HU ZHANG ◽  
JIANGBO SHA
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Compressive Strength ◽  
Room Temperature ◽  
Vacuum Induction Melting ◽  
Vacuum Induction Furnace ◽  
Induction Melting ◽  
Arc Melting ◽  
Temperature Fracture ◽  
High Temperature Compressive Strength

This paper dealt with the effect of different induction melting technologies on mechanical properties of Nb -16 Si -22 Ti -2 Al -2 Hf -17 Cr alloy. The cast ingots were fabricated first by arc-melting, and then remolten in the vacuum induction furnace. The results showed that the ingot with refining process of 1800°C/15min and 0.1 at% C addition had finer microstructure and higher room-temperature fracture toughness. In addition, the compressive strength of the ingot with refining technology of 1700°C/10min was 315MPa at 1250°C. However, the arc melting ingot had the lowest fracture toughness and high-temperature compressive strength.

Effect of Trace Strontium Addition on Microstructure and Room Temperature Fracture Toughness of Nb-12Si-22Ti Alloys

2016 ◽  
Vol 849 ◽  
pp. 603-608 ◽  
Author(s):  
Mei Ling Wu ◽  
Feng Wei Guo ◽  
Ming Li ◽  
Ya Fang Han
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Fracture ◽  
The Relationship ◽  
Scanning Electron

The effect of strontium (Sr) addition (0.2 at.%) on the microstructure and mechanical properties of Nb-12Si-22Ti alloys were studied. Microstructure of the alloys was observed by scanning electron microscope, and their phase compositions were analyzed with X-ray diffraction and Electro-Probe Microanalyzer. The room temperature fracture toughness was measured. The results indicated that the phases of Nbss and Nb3Si were presented in Nb-12Si-22Ti alloys. However, with the Al and Sr addition, the alloys were composed of Nbss and β-Nb5Si3. Compared with the Nb-12Si-22Ti alloys, the value of room temperature fracture toughness increased about 46% and 73% with the addition of Al and Sr alloy, respectively. The relationship between the microstructure and the mechanical properties was discussed.

scholarly journals Low-temperature degradation resistance and plastic deformation of ATZ ceramics stabilized by CaO

2021 ◽  
Vol 2103 (1) ◽  
pp. 012075
Author(s):  
AA Dmitrievskiy ◽  
DG Zhigacheva ◽  
VM Vasyukov ◽  
PN Ovchinnikov
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Plastic Deformation ◽  
Compressive Strength ◽  
Phase Composition ◽  
Low Temperature ◽  
Uniaxial Compression ◽  
Calcium Oxide ◽  
Tetragonal Phase ◽  
Room Temperature

Abstract In this work, the phase composition (relative fractions of monoclinic m-ZrO2, tetragonal t-ZrO2, and cubic c-ZrO2 phases) and mechanical properties (hardness, fracture toughness, compressive strength) of alumina toughened zirconia (ATZ) ceramics, with an addition of silica were investigated. Calcium oxide was used as a stabilizer for the zirconia tetragonal phase. It was shown that CaO-ATZ+SiO2 ceramics demonstrate increased resistance to low-temperature degradation. The plasticity signs at room temperature were found due to the SiO2 addition to CaO-ATZ ceramics. A yield plateau appears in the uniaxial compression diagram at 5 mol. % SiO2 concentration. It is hypothesized that discovered plasticity is due to the increased t→m transformability.

Strength and Toughness of Silicide Matrix Materials Consolidated by Hot Isostatic Pressing

1993 ◽  
Vol 322 ◽  
Author(s):  
R. Suryanarayanan ◽  
S. M. L. Sastry ◽  
K. L. Jerina
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Creep Resistance ◽  
Room Temperature ◽  
Hot Isostatic Pressing ◽  
Molybdenum Disilicide ◽  
High Temperature Strength ◽  
Isostatic Pressing ◽  
Temperature Fracture ◽  
Hip Process

AbstractSubstantial improvements have been reported in high temperature strength and creep resistance, and room temperature fracture toughness of molybdenum disilicide (MoSi2) reinforced with ductile or brittle reinforcements. The influence of Hot Isostatic Pressing (HIP) process parameters on the mechanical properties of MoSi2 based alloys was studied. Monolithic MoSi2 powder and MoSi2 powder blended with either niobium powder or silicon carbide whisker reinforcements were consolidated by HIP at 1200 − 1400°C, 207 MPa, and 1 - 4 hrs. The HIP'ed compacts were characterized for compression strength and creep resistance at 1100-1300°C. Fracture toughness was measured on single edge notched rectangular specimens at room temperature. Mechanical properties were correlated with post-HIP microstructural features.

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.

Effect of Annealing on the Microstructures and Mechanical Properties of Mo3Si-Mo5Si3 Eutectic

2004 ◽  
Vol 449-452 ◽  
pp. 697-700
Author(s):  
Hai Bo Yang ◽  
Wei Li ◽  
Ai Dang Shan ◽  
Jian Sheng Wu
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Strain Rate ◽  
Eutectic Alloy ◽  
Vickers Hardness ◽  
Room Temperature ◽  
Beam Specimen ◽  
Single Edge ◽  
Arc Melting ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of arc-melting processed Mo3Si-Mo5Si3 eutectic have been investigated. The Vickers hardness of Mo3Si-Mo5Si3 eutectic alloy at room temperature is on the order of 1350Hv. The fracture toughness value of the alloy at room temperature is 1.39MPam1/2 measured by Single edge-notched beam specimen technique and 1.61MPam1/2 measured by Indentation technique. The compressive strengths at 1300 oC and 1400 oC under a strain rate of 10-4s-1 are about 550MPa and 300MPa respectively.

Microstructure and Mechanical Properties of an Advanced Niobium Based Ultrahigh Temperature Alloy

2007 ◽  
Vol 539-543 ◽  
pp. 3690-3695 ◽  
Author(s):  
X.P. Guo ◽  
L.M. Gao ◽  
Ping Guan ◽  
K. Kusabiraki ◽  
Heng Zhi Fu
Keyword(s):  
Mechanical Properties ◽  
Electron Beam ◽  
Directional Solidification ◽  
Room Temperature ◽  
Zone Melting ◽  
Floating Zone ◽  
Directionally Solidified ◽  
Microstructure And Mechanical Properties ◽  
Temperature Fracture ◽  
Ultrahigh Temperature

The microstructure and mechanical properties including room temperature fracture toughness Kq, tensile strengthσb and elongationδ at 1250°C of the Nb based alloy directionally solidified in an electron beam floating zone melting (EBFZM) furnace have been evaluated. The microstructure is primarily composed of Nb solid solution (Nbss), α-(Nb)5Si3 and (Nb)3Si phases. After directional solidification with the moving rate of electron beam gun R being respectively 2.4, 4.8 and 7.2 mm/min, the primary Nbss dendrites, Nbss + (Nb)5Si3/(Nb)3Si eutectic colonies (lamellar or rod-like) and divorced Nb silicide plates align along the longitudinal axes of the specimens. When R = 2.4 mm/min, the best directional microstructure is obtained. Directional solidification has significantly improved theσb at 1250°C and Kq. The maximumσb occurs for the specimens with R = 2.4 mm/min and is about 85.0 MPa, meanwhile, the Kq is about 19.4 MPam1/2.

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.

The Fracture Toughness and DBTT of MoB Particle-Reinforced MoSi2 Composites

2007 ◽  
Vol 280-283 ◽  
pp. 1471-1474
Author(s):  
Zhi Xiong ◽  
Gang Wang ◽  
Wan Jiang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperature ◽  
Room Temperature ◽  
Probable Mechanism ◽  
Vickers Indentation ◽  
Indentation Technique ◽  
Testing Method ◽  
Temperature Fracture

The room temperature fracture toughness and the high temperature DBTT of MoB particle-reinforced MoSi2 composites were investigated using Vickers indentation technique and MSP testing method， respectively. Modified Small Punch (MSP) test is a method for evaluation of mechanical properties using very small specimens, and it’s appropriate for the determination of strength and DBTT. It was found that the approximate fracture toughness of the composite is 1.3 times that of monolithic MoSi2, and its DBTT is 100°C higher than that of monolithic MoSi2 materials. Cracks deflection is a probable mechanism responsible for this behavior.

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