scholarly journals In Situ Formation of TiB2 in Fe-B System with Titanium Addition and Its Influence on Phase Composition, Sintering Process and Mechanical Properties

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4188
Author(s):  
Mateusz Skałoń ◽  
Marek Hebda ◽  
Benedikt Schrode ◽  
Roland Resel ◽  
Jan Kazior ◽  
...  

Interaction of iron and boron at elevated temperatures results in the formation of an E (Fe + Fe2B) eutectic phase that plays a great role in enhancing mass transport phenomena during thermal annealing and therefore in the densification of sintered compacts. When cooled down, this phase solidifies as interconnected hard and brittle material consisting of a continuous network of Fe2B borides formed at the grain boundaries. To increase ductile behaviour, a change in precipitates’ stoichiometry was investigated by partially replacing iron borides by titanium borides. The powder of elemental titanium was introduced to blend of iron and boron powders in order to induce TiB2 in situ formation. Titanium addition influence on microstructure, phase composition, density and mechanical properties was investigated. The observations were supported with thermodynamic calculations. The change in phase composition was analysed by means of dilatometry and X-ray diffraction (XRD) coupled with thermodynamic calculations.

2015 ◽  
Vol 651-653 ◽  
pp. 677-682 ◽  
Author(s):  
Anatoliy Popovich ◽  
Vadim Sufiiarov ◽  
Evgenii Borisov ◽  
Igor Polozov

The article presents results of a study of phase composition and microstructure of initial material and samples obtained by selective laser melting of titanium-based alloy, as well as samples after heat treatment. The effect of heat treatment on microstructure and mechanical properties of specimens was shown. It was studied mechanical behavior of manufactured specimens before and after heat treatment at room and elevated temperatures as well. The heat treatment allows obtaining sufficient mechanical properties of material at room and elevated temperatures such as increase in ductility of material. The fractography of samples showed that they feature ductile fracture with brittle elements.


2021 ◽  
Vol 118 (6) ◽  
pp. 606
Author(s):  
Nandish Girishbhai Soni ◽  
Akash Ganesh Mahajan ◽  
Kaustubh Ramesh Kambale ◽  
Sandeep Prabhakar Butee

Fabrication with the in-situ formation of W2C reinforced medium carbon steel (MCS) MMC’s was attempted using W or WO3 and graphite addition to steel. The P/M route comprising milling, compaction and sintering at 1050 °C and 1120 °C respectively in 90% N2 + 10% H2 atmosphere was adopted. Both SEM and BET studies revealed the particle size to be around 100, 7 and 40 µm for MCS, W and WO3, respectively. A complete conversion of tungsten into tungsten semicarbide (W2C) was noted in XRD for the tungsten additions of ∼6, 9 and 12 wt.% with stoichiometrically balanced C (graphite) addition of 0, 0.2 and 0.4 wt.%. However, WO3 + C addition (balanced as above) revealed the partial conversion of WO3 to W2C. The peaks of Fe3C were observed only for MCS + W + C samples and not for MCS + WO3 + C samples in XRD. In SEM, the WO3 phase appeared porous and partially converted, whereas, W2C phase was dense. Sintered density improved for the addition of W, whereas it monotonically reduced for WO3 addition to MCS + C samples. Higher hardness, compressive strength, and wear resistance was noted for W addition than WO3 to MCS+C samples.


2021 ◽  
pp. 32-47
Author(s):  
N.A. Nochovnaya ◽  
◽  
V.I. Ivanov ◽  
L.Yu. Avilochev ◽  
◽  
...  

Intermetallide alloys based on the Al2Ti compound are the most promising heat-resistant materials for future energy plants.The review examines the mechanical properties of the Al2Ti Intermetalide, two-phase alloys based on it and the doped niobium alloy. For use at temperatures of up to 950 °С, alloys with phase composition r-Al2Ti + γ-TiAl and platemicrostructure with additional doping of refractory elements are of interest.


2017 ◽  
Vol 12 (1) ◽  
pp. 63-77 ◽  
Author(s):  
Siriporn Sirikingkaew ◽  
Nuta Supakata

This study presents the development of geopolymer bricks synthetized from industrial waste, including fly ash mixed with concrete residue containing aluminosilicate compound. The above two ingredients are mixed according to five ratios: 100:0, 95:5, 90:10, 85:15, and 80:20. The mixture's physico-mechanical properties, in terms of water absorption and the compressive strength of the geopolymer bricks, are investigated according to the TIS 168-2546 standard. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses are used to investigate the microstructure and the elemental and phase composition of the brick specimens. The results indicate that the combination of fly ash and concrete residue represents a suitable approach to brick production, as required by the TIS 168–2546 standard.


Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 873
Author(s):  
Chun-Liang Yeh ◽  
Chih-Yao Ke

The fabrication of intermetallic/ceramic composites by combustion synthesis in the mode of self-propagating high-temperature synthesis (SHS) was investigated in the Al–Ni–Ti system with the addition of B4C. Two reaction systems were employed: one was used to produce the composites of xNiAl–2TiB2–TiC with x = 2–7, and the other was used to synthesize yNi3Al–2TiB2–TiC with y = 2–7. The reaction mechanism of the Al–Ni–Ti system was strongly influenced by the presence of B4C. The reaction of B4C with Ti was highly exothermic, so the reaction temperature and combustion velocity decreased due to increasing levels of Ni and Al in the reactant mixture. The activation energies of Ea = 110.6 and 172.1 kJ/mol were obtained for the fabrication of NiAl- and Ni3Al-based composites, respectively, by the SHS reaction. The XRD (X-ray diffraction) analysis showed an in situ formation of intermetallic (NiAl and Ni3Al) and ceramic phases (TiB2 and TiC) and confirmed no reactions taking place between Ti and Al or Ni. The microstructure of the product revealed large NiAl and Ni3Al grains and small TiB2 and TiC particles. With the addition of TiB2 and TiC, the hardness of NiAl and Ni3Al was considerably increased and the toughness was also improved.


RSC Advances ◽  
2019 ◽  
Vol 9 (38) ◽  
pp. 21748-21759 ◽  
Author(s):  
Jieun Jeong ◽  
Muhammad Ayyoob ◽  
Ji-Heung Kim ◽  
Sung Woo Nam ◽  
Young Jun Kim

Current work provides a synergistic approach to prepare super tough PLA without any significant loss of its excellent intrinsic mechanical properties.


1992 ◽  
Vol 274 ◽  
Author(s):  
Takashi Fujii ◽  
Hironobu Muragaki ◽  
Hiraku Hatano ◽  
Shin-Ichi Hirano

ABSTRACTSimultaneous additions of lanthanum aluminate(LAL) and Al2O3 to Ce-TZP (12mol% CeO2-ZrO2) lead to the in-situ formation of lanthanum- β-alumina(LBA) platelets (∼1.0.μ m in width and 5 ∼10 μ m in length) in the Ce-TZP matrix during sintering. The composites showed a fracture toughness(SEPB method) of 9.5 MPa · m0.5 and fracture strength of 960 MPa. which are remarkably improved from Ce-TZP sintered body (8.5 MPa · m0.5 and 560 MPa).The composites also exhibit the no degradation by hydrothermal treatment.


2010 ◽  
Vol 113-116 ◽  
pp. 1712-1715
Author(s):  
Cheng Yu Wang ◽  
Chang Yu Liu ◽  
Jian Li

The preparation of hydrophobic CaCO3-wood composite through a double-diffusive method using dodecanoic acid as organic substrate is demonstrated. The product was characterized by the contact angle analysis, X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR) and scanning electron microscope (SEM). The mechanical properties of the product were measured. The results show that the synthesized CaCO3 fills in the wood cell and covers the surface of wood. The CaCO3-wood composite is hydrophobic. The mechanical properties of wood composite have significantly increased.


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