Mechanical Properties of NiAl Nanocomposite Intermetallic Alloys With Varying Porosity

Author(s):  
Emily M. Hunt ◽  
Pilaka Murty

Recent advancements in the field of nano-technology focused attention on developing materials with new and useful characteristics. In particular, there is interest in designing nanocomposite thermites for combustion synthesis applications. The composite material consists of nano-scale particles that are in nearly atomic scale proximity but constrained from reaction until triggered. Once initiated, the reaction will become self-sustaining and a new intermetallic alloy product will be produced. An example of this type of reaction is between Ni and Al such that a nickel-aluminide alloy is produced (Eq. (1) [1].

1994 ◽  
Vol 350 ◽  
Author(s):  
J. H. Schneibel ◽  
K. B. Alexander

AbstractSeveral compositions of the intermetallic alloy Ni3Al were examined with respect to (a) their wetting of Al2O3 and (b) their energy absorption capability in Al2O3/Ni3Al laminates. Wetting is enhanced by small additions of carbon (e.g., 0.1 at. %), and bonding by additions of zirconium (e.g., 1 at. %). Chevron-notched laminate specimens were tested in three-point bending to assess the energy absorption due to the presence of a thin layer of Ni3Al. A nickel aluminide with the composition Ni-22Al-lZr-0.1C-0.1B was found to have a reasonable combination of wetting, adhesion and energy absorption. Interfacial bonding was found to be weak in all laminates.


2015 ◽  
Vol 788 ◽  
pp. 151-156 ◽  
Author(s):  
Lilia Shevtsova ◽  
Tatyana Sameyshcheva ◽  
Dmitry Terentyev ◽  
Iuliia Malyutina ◽  
Aleksey Larichkin ◽  
...  

Structure and mechanical properties of the PN85YU15 - Ni composite materials obtained by spark plasma sintering were investigated. Two types of powder mixtures, namely, nickel mixed with coarse-grained nickel aluminide and nickel mixed with fine-grained nickel aluminide were used to obtain the composites. Nickel aluminide and nickel powders were taken in the ratio 7:3 respectively. The effect of the initial nickel aluminide particle sizes and plastic deformation due to the ball milling on the structure and mechanical properties of materials sintered at 1100 °C and pressure of 40 MPa was determined. Plastic deformation and refining the initial intermetallic powder particle sizes leads to increasing the sintered material relative density to 95%. The tensile strength of the PN85YU15-Ni composite material obtained by sintering of the milled PN85YU15 powder and nickel in the ratio 7:3 was 1060 MPa. This value is almost twice as high as the tensile strength of the composite containing a no significant plastic deformed coarse-grained intermetallic compound powder (590 MPa), and three times higher than the tensile strength of the sintered nickel aluminide powder (380 MPa).


Author(s):  
E. Sukedai ◽  
H. Mabuchi ◽  
H. Hashimoto ◽  
Y. Nakayama

In order to improve the mechanical properties of an intermetal1ic compound TiAl, a composite material of TiAl involving a second phase Ti2AIN was prepared by a new combustion reaction method. It is found that Ti2AIN (hexagonal structure) is a rod shape as shown in Fig.1 and its side surface is almost parallel to the basal plane, and this composite material has distinguished strength at elevated temperature and considerable toughness at room temperature comparing with TiAl single phase material. Since the property of the interface of composite materials has strong influences to their mechanical properties, the structure of the interface of intermetallic compound and nitride on the areas corresponding to 2, 3 and 4 as shown in Fig.1 was investigated using high resolution electron microscopy and image processing.


Author(s):  
O. Popoola ◽  
A.H. Heuer ◽  
P. Pirouz

The addition of fibres or particles (TiB2, SiC etc.) into TiAl intermetallic alloys could increase their toughness without compromising their good high temperature mechanical and chemical properties. This paper briefly discribes the microstructure developed by a TiAl/TiB2 composite material fabricated with the XD™ process and forged at 960°C.The specimens for transmission electron microscopy (TEM) were prepared in the usual way (i.e. diamond polishing and argon ion beam thinning) and examined on a JEOL 4000EX for microstucture and on a Philips 400T equipped with a SiLi detector for microanalyses.The matrix was predominantly γ (TiAl with L10 structure) and α2(TisAl with DO 19 structure) phases with various morphologies shown in figure 1.


Sensors ◽  
2020 ◽  
Vol 21 (1) ◽  
pp. 145
Author(s):  
Lesław Kyzioł ◽  
Katarzyna Panasiuk ◽  
Grzegorz Hajdukiewicz ◽  
Krzysztof Dudzik

Due to the unique properties of polymer composites, these materials are used in many industries, including shipbuilding (hulls of boats, yachts, motorboats, cutters, ship and cooling doors, pontoons and floats, torpedo tubes and missiles, protective shields, antenna masts, radar shields, and antennas, etc.). Modern measurement methods and tools allow to determine the properties of the composite material, already during its design. The article presents the use of the method of acoustic emission and Kolmogorov-Sinai (K-S) metric entropy to determine the mechanical properties of composites. The tested materials were polyester-glass laminate without additives and with a 10% content of polyester-glass waste. The changes taking place in the composite material during loading were visualized using a piezoelectric sensor used in the acoustic emission method. Thanks to the analysis of the RMS parameter (root mean square of the acoustic emission signal), it is possible to determine the range of stresses at which significant changes occur in the material in terms of its use as a construction material. In the K-S entropy method, an important measuring tool is the extensometer, namely the displacement sensor built into it. The results obtained during the static tensile test with the use of an extensometer allow them to be used to calculate the K-S metric entropy. Many materials, including composite materials, do not have a yield point. In principle, there are no methods for determining the transition of a material from elastic to plastic phase. The authors showed that, with the use of a modern testing machine and very high-quality instrumentation to record measurement data using the Kolmogorov-Sinai (K-S) metric entropy method and the acoustic emission (AE) method, it is possible to determine the material transition from elastic to plastic phase. Determining the yield strength of composite materials is extremely important information when designing a structure.


2012 ◽  
Vol 496 ◽  
pp. 281-284
Author(s):  
Wen Wen Liu ◽  
Zhi Wang ◽  
Yun Hai Du ◽  
Xian Zhong Xu ◽  
Da Quan Liu ◽  
...  

An improved accurate speckle projection method is used for study the mechanical properties of the composite material film in the paper. A system for deformation measurement is developed with the telecentric lenses, in which such conventional lens’ disadvantages such as lens distortion and perspective error will be diminished. Experiments are performed to validate the availability and reliability of the calibration method. The system can also be used to measure the dynamic deformation and then results are also given.


2010 ◽  
Vol 431-432 ◽  
pp. 523-526
Author(s):  
Han Lian Liu ◽  
Chuan Zhen Huang ◽  
Shou Rong Xiao ◽  
Hui Wang ◽  
Ming Hong

Under the liquid-phase hot-pressing technique, the multi-scale titanium diboride matrix nanocomposite ceramic tool materials were fabricated by adding both micro-scale and nano-scale TiN particles into TiB2 with Ni and Mo as sintering aids. The effect of content of nano-scale TiN and sintering temperature on the microstructure and mechanical properties was studied. The result showed that flexural strength and fracture toughness of the composites increased first, and then decreased with an increase of the content of nano-scale TiN, while the Vickers hardness decreased with an increase of the content of nano-scale TiN. The optimal mechanical properties were flexural strength 742 MPa, fracture toughness 6.5 MPa•m1/2 and Vickers hardness 17GPa respectively. The intergranular and transgranular fracture mode were observed in the composites. The metal phase can cause ductility toughening and crack bridging, while crack deflection and transgranular fracture mode could be brought by micro-scale TiN and nano-scale TiN respectively.


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