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.

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.

Elevated Temperature Mechanical Properties of a Directionally Solidified NiAl/Cr(Mo)-Hf Alloy

2005 ◽  
Vol 297-300 ◽  
pp. 1477-1481
Author(s):  
Chun Mei Xu ◽  
Jian Ting Guo ◽  
Xi Shan Xie
Keyword(s):  
Mechanical Properties ◽  
Transition Temperature ◽  
Strain Rate ◽  
Eutectic Alloy ◽  
Tensile Testing ◽  
Room Temperature ◽  
Directionally Solidified ◽  
Interface Boundary ◽  
Brittle To Ductile Transition ◽  
Nial Matrix

The microstructure of directionally solidified (DS) NiAl-28Cr-5Mo-1Hf eutectic alloy was investigated by SEM and TEM. The eutectic alloy is composed of NiAl matrix , Cr (Mo) phase and a small amount of Heusler phase. Tensile testing of this alloy was performed from room temperature to 1373K. The brittle-to-ductile transition temperature (BDTT) is dependent on strain rate, with two orders of increase on strain rate resulting in a100K increase in transition temperature. The observation of fracture surface showed that at temperature above BDTT, the fractograph changes from NiAl cleavage and debonding along NiAl/Cr(Mo) interface boundary to ductile in nature.

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.

scholarly journals Effects of Substitution of Y with Yb and Ce on the Microstructures and Mechanical Properties of Mg88.5Zn5Y6.5

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 31
Author(s):  
Hongxin Liao ◽  
Taekyung Lee ◽  
Jiangfeng Song ◽  
Jonghyun Kim ◽  
Fusheng Pan
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
Yield Strength ◽  
Creep Resistance ◽  
Room Temperature ◽  
High Thermal Stability ◽  
Long Period ◽  
Microstructures And Mechanical Properties

The microstructures and mechanical properties of the Mg88.5Zn5Y6.5-XREX (RE = Yb and Ce, X = 0, 1.5, 3.0, and 4.5) (wt.%) alloys were investigated in the present study. Mg88.5Zn5Y6.5 is composed of three phases, namely, α-Mg, long-period stacking ordered (LPSO) phases, and intermetallic compounds. The content of the LPSO phases decreased with the addition of Ce and Yb, and no LPSO phases were detected in Mg88.5Zn5Y2.0Yb4.5. The alloys containing the LPSO phases possessed a stratified microstructure and exhibited excellent mechanical properties. Mg88.5Zn5Y5.0Ce1.5 exhibited the highest creep resistance and mechanical strength at both room temperature and 200 °C, owing to its suitable microstructure and high thermal stability. The yield strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature was 358 MPa. The ultimate tensile strength of Mg88.5Zn5Y5.0Ce1.5 at room temperature and 200 °C was 453 MPa and 360 MPa, respectively.

Local Investigations of the Mechanical Properties of Ultrafine Grained Metals by Nanoindentations

2006 ◽  
Vol 503-504 ◽  
pp. 31-36 ◽  
Author(s):  
Johannes Mueller ◽  
Karsten Durst ◽  
Dorothea Amberger ◽  
Matthias Göken
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Strain Rate Sensitivity ◽  
Room Temperature ◽  
Rate Sensitivity ◽  
Strain Rates ◽  
Fcc Metals ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Indentation Strain

The mechanical properties of ultrafine-grained metals processed by equal channel angular pressing is investigated by nanoindentations in comparison with measurements on nanocrystalline nickel with a grain size between 20 and 400 nm produced by pulsed electrodeposition. Besides hardness and Young’s modulus measurements, the nanoindentation method allows also controlled experiments on the strain rate sensitivity, which are discussed in detail in this paper. Nanoindentation measurements can be performed at indentation strain rates between 10-3 s-1 and 0.1 s-1. Nanocrystalline and ultrafine-grained fcc metals as Al and Ni show a significant strain rate sensitivity at room temperature in comparison with conventional grain sized materials. In ultrafine-grained bcc Fe the strain rate sensitivity does not change significantly after severe plastic deformation. Inelastic effects are found during repeated unloading-loading experiments in nanoindentations.

A Study on Reaction Bonded Ceramics Fabricated by Silicon Infiltration to B4C Preforms

2012 ◽  
Vol 724 ◽  
pp. 343-346 ◽  
Author(s):  
Rong Zhen Liu ◽  
Qing Wen Duan ◽  
Wen Wei Gu ◽  
Hai Yun Jin ◽  
Shao Chun Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Theoretical Result ◽  
Boron Carbide ◽  
Theoretical Calculation ◽  
Vickers Hardness ◽  
Volume Expansion ◽  
Maximum Density ◽  
Infiltration Process

Silicon was infiltrated into B4C preforms to fabricate B4C based composites ceramics at 1600 °C under vacuum circumstance. In this paper, silicon infiltration process was discussed by theoretical calculation. The volume expansion caused by reactions between silicon and boron carbide was about 89.1% from the calculation. In our study, the maximum density of B4C preform for the infiltration of silicon was about 1.5g/cm3 which was larger than theoretical result. The results of mechanical behavior showed that B4C based composites had excellent mechanical properties with a density lower than 2.6g/cm3, Vickers-hardness of this material was 27.2GPa, and this material showed a flexural strength of 349MPa and fracture toughness of 3.8 MPa*m1/2.

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.

Effects of TiN Content on Mechanical Properties and Microstructure of ATN Materials

2013 ◽  
Vol 589-590 ◽  
pp. 590-593 ◽  
Author(s):  
Min Wang ◽  
Jun Zhao
Keyword(s):  
Mechanical Properties ◽  
Mechanical Property ◽  
Fracture Toughness ◽  
Vickers Hardness ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Ceramic Materials ◽  
Hot Press ◽  
Hot Press Sintering ◽  
Tin Content

In order to investigate the effects of TiN content on Al2O3/TiN ceramic material (ATN), the ATN ceramic materials were prepared of TiN content in 30%, 40%, 50%, 60% in the condition of hot press sintering. The sintering temperature is 1700°C, the sintering press is 32MPa, and the holding time are 5min, 10min, 15min. The effects of TiN content on mechanical properties and microstructure of ATN ceramic materials were investigated by analyzing the bending strength, hardness, fracture toughness. The results show that ATN50 has the best mechanical property, its bending strength is 659.41MPa, vickers hardness is 13.79GPa, fracture toughness is 7.06MPa·m1/2. It is indicated that the TiN content has important effect on microstructure and mechanical properties of ATN ceramic materials.

Fabrication of Carbon Nanotube Reinforced Boron Carbide Composite by Hot-Pressing Following Extrusion Molding

2014 ◽  
Vol 616 ◽  
pp. 27-31 ◽  
Author(s):  
Tomohiro Kobayashi ◽  
Katsumi Yoshida ◽  
Toyohiko Yano
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Carbon Nanotube ◽  
Boron Carbide ◽  
Vickers Hardness ◽  
Hot Pressing ◽  
Bending Strength ◽  
Extrusion Direction ◽  
Sem Observation

The CNT/B4C composite with Al2O3 additive was fabricated by hot-pressing following extrusion molding of a CNT/B4C paste, and mechanical properties of the obtained composite were investigated. Many CNTs in the composite aligned along the extrusion direction from SEM observation. 3-points bending strength of the composite was slightly lower than that of the monolithic B4C. Elastic modulus and Vickers hardness of the composite drastically decreased with CNT addition. Fracture toughness of the composite was higher than that of the monolithic B4C.

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