CIRCUITRY , STRUCTURE AND PROPERTIES OF HETEROGENEOUS MATERIALS

2021 ◽  
Vol 2021 (9) ◽  
pp. 29-35
Author(s):  
Dmitriy Kryukov ◽  
Aleksey Krivenkov ◽  
Sergey Chugunov

Currently, heterogeneous materials based on titanium and aluminum alloys are widely used as promising armor materials. When a ballistic object is exposed to the armor material, brittle cracks that occur at the contact point spread in such a way that composite material is in state of decay both deep into and along the interlayer boundaries of the joint, while there is a violation of the composite structure and loss of the mechanical strength of the armor element. In this regard, the task of developing new reinforcement schemes for composite armor is urgent. One of the most promising technologies in the field of creating and developing new composite non-metallic armor materials is explosion bonding. The authors of the work proposed a new scheme for reinforcing a heterogeneous metal material by means of explosion bonding, which uses internal perforated reinforcing layers that serve as elements preventing the development of brittle fracture at the point of ballistic contact. To increase the efficiency of the destruction of a ballistic object in the composite structure, the authors proposed the formation of highly solid intermetallic compounds at the boundary between the metal of the base of a viscous metal matrix and the reinforcing element by subsequent heat treatment of the material. The conducted micro-X-ray spectral analysis of intermetallic compounds showed their correspondence to the chemical compound α-titanium (TiAl3). Comparison of the obtained level of physical and mechanical properties of the developed heterogeneous armored material with analogues suggests that the expected level of the composite protection class against small arms is in the range from Br4 to Br5 according to GOST R 50963-96 with an armor thickness of 40 to 60 mm, which makes it possible to reduce the weight of armored vehicles significantly and, as a result, increase its tactical and technical characteristics.

Author(s):  
Eric N. Landis

Microtomography is a powerful tool that allows us to image materials at close to micron resolution. In the case of heterogeneous materials such as wood-based and cement-based composite materials were microstructure-property relationships are extremely difficult to quantify, microtomography enables us to make quantitative assessments of internal structure. Through 3D image analysis we can characterize a variety of parameters that affect a range of physical and mechanical properties. This paper provides an overview of synchrotron-based and laboratory-based microtomography applications to heterogeneous materials, along with the 3D image processing required to extract quantitative information.


1990 ◽  
Author(s):  
Young K. Kim ◽  
David K. Shuh ◽  
R. S. Williams ◽  
Larry P. Sadwick ◽  
Kang L. Wang

2021 ◽  
Vol 7 (3) ◽  
pp. 42
Author(s):  
Jiba N. Dahal ◽  
Kalangala Sikkanther Syed Ali ◽  
Sanjay R. Mishra

Intermetallic compounds of Dy2Fe16Ga1−xNbx (x = 0.0 to 1.00) were synthesized by arc melting. Samples were investigated for structural, magnetic, and hyperfine properties using X-ray diffraction, vibration sample magnetometer, and Mossbauer spectrometer, respectively. The Rietveld analysis of room temperature X-ray diffraction data shows that all the samples were crystallized in Th2Fe17 structure. The unit cell volume of alloys increased linearly with an increase in Nb content. The maximum Curie temperature Tc ~523 K for x = 0.6 sample is higher than Tc = 153 K of Dy2Fe17. The saturation magnetization decreased linearly with increasing Nb content from 61.57 emu/g for x = 0.0 to 42.46 emu/g for x = 1.0. The Mössbauer spectra and Rietveld analysis showed a small amount of DyFe3 and NbFe2 secondary phases at x = 1.0. The hyperfine field of Dy2Fe16Ga1−xNbx decreased while the isomer shift values increased with the Nb content. The observed increase in isomer shift may have resulted from the decrease in s electron density due to the unit cell volume expansion. The substantial increase in Tc of thus prepared intermetallic compounds is expected to have implications in magnets used for high-temperature applications.


2017 ◽  
Vol 866 ◽  
pp. 199-203
Author(s):  
Chidchanok Chainej ◽  
Suparut Narksitipan ◽  
Nittaya Jaitanong

The aims of this research were study the microstructures and mechanical properties for partial replacement of cement with Fly ash (FA) and kaolin waste (KW). Ordinary Portland cement were partially replaced with FA and KW in the range of 25-35% and 10-25% by weight of cement powder. The kaolin waste was ground for 180 minutes before using. The specimen was packing into an iron mold which sample size of 5×5×5 cm3. Then, the specimens were kept at room temperature for 24 hours and were moist cured in the incubation lime water bath at age of 3 days. After that the specimens were dry cured with plastic wrap at age of 3, 7, 14 and 28 days. After that the compounds were examined by x-ray diffraction patterns (XRD) and the microstructures were examined by scanning electron microscopy (SEM). The compressive strength was then investigated.


2018 ◽  
Vol 170 ◽  
pp. 03030 ◽  
Author(s):  
Rustem Mukhametrakhimov ◽  
Liliya Lukmanova

The paper studies features of the hydration process of the modified blended cement for fiber cement panels (FCP) using differential thermal analysis, X-ray diffraction analysis, electron microscopy and infrared spectroscopy. It is found that deeper hydration process in silicate phase, denser and finer crystalline structure form in fiber cement matrix based on the modified blended cement. Generalization of this result to the case of fiber cement panels makes it possible to achieve formation of a denser and homogeneous structure with increased physical and mechanical properties.


2021 ◽  
Vol 1040 ◽  
pp. 178-184
Author(s):  
Andrey S. Dolgin ◽  
Aleksei I. Makogon ◽  
Sergey P. Bogdanov

Today 3D printing with ceramics is a promising direction in the development of additive technologies. In this work, we have developed a technology for printing with ceramic pastes based on aluminum oxide and wax, namely: an extruder for printing with ceramic pastes was modeled and manufactured, the composition of the slip was selected and the paste for printing was made. After choosing the print parameters, test samples were printed: a disk and a box. Since 3D printing with ceramics is just one of the stages of manufacturing ceramic products, then we selected the parameters for drying and sintering the raw material. Drying of products is necessary to burn off an excess amount of a binder (paraffin), and due to sintering; the raw material acquires final strength and mechanical characteristics. After sintering, the sintering parameters and physical and mechanical properties of the products were measured. The microstructure of the printed products was studied using scanning electron microscopy. The phase change during sintering was studied by X-ray analysis. All obtained properties were compared with a reference sample (corundum tile made of aluminum oxide of the same grade, but using traditional ceramic technology, including pressing, drying and sintering of the product). In terms of all properties, the printed ceramics are not significantly inferior to the reference sample; however, in general, the additive technology has more advantages, such as a wide variety of shapes, shorter manufacturing time for parts, and lower energy costs.


Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1473 ◽  
Author(s):  
Kwangjae Park ◽  
Dasom Kim ◽  
Kyungju Kim ◽  
Seungchan Cho ◽  
Kenta Takagi ◽  
...  

Aluminum (Al)-stainless steel 316L (SUS316L) composites were successfully fabricated by the spark plasma sintering process (SPS) using pure Al and SUS316L powders as raw materials. The Al-SUS316L composite powder comprising Al with 50 vol.% of SUS316L was prepared by a ball milling process. Subsequently, it was sintered at 630 °C at a pressure of 200 MPa and held for 5 min in a semisolid state. The X-ray diffraction (XRD) patterns show that intermetallic compounds such as Al13Fe4 and AlFe3 were created in the Al-SUS316L composite because the Al and SUS316L particles reacted together during the SPS process. The presence of these intermetallic compounds was also confirmed by using XRD, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), and EDS mapping. The mechanical hardness of the Al-SUS316L composites was analyzed by a Vickers hardness tester. Surprisingly, the Al-SU316L composite exhibited a Vickers hardness of about 620 HV. It can be concluded that the Al-SUS316L composites fabricated by the SPS process are lightweight and high-hardness materials that could be applied in the engineering industry such as in automobiles, aerospace, and shipbuilding.


Author(s):  
Georg Frommeyer ◽  
Sven Knippscheer

Aluminum-rich intermetallic compounds of the Al3X-type with transmission metals (X = Ti. Zr, Nb, V) of Groups IVb and Vb are of interest in the development of novel high-temperature and lightweight structural materials. This article describes the important physical and mechanical properties of trialuminides with DO22 structure and their L12 variations. Topical coverage includes: crystal structure and selected physical properties, plastic deformation, oxidation behavior, and applications.


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