Insight into the electronic and mechanical properties of novel TMCrSi ternary silicides from first-principles calculations

2018 ◽  
Vol 20 (23) ◽  
pp. 15863-15870 ◽  
Author(s):  
Y. Pan ◽  
W. M. Guan ◽  
Y. Q. Li
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Melting Point ◽  
First Principles ◽  
Functional Materials ◽  
High Melting ◽  
First Principles Calculations ◽  
High Melting Point ◽  
Metal Silicides ◽  
Insight Into

Transition metal silicides (TMSis) are attractive advanced functional materials due to their low electronic resistivity, high melting-point, excellent mechanical properties and thermal stability.

Effect of Transition Metal Silicides on Microstructure and Mechanical Properties of Ultra-High Temperature Ceramics

2013 ◽  
pp. 125-179 ◽  
Author(s):  
Laura Silvestroni ◽  
Diletta Sciti
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Melting Point ◽  
Leading Edge ◽  
High Melting ◽  
High Melting Point ◽  
Ultra High Temperature Ceramics ◽  
Sintering Additives ◽  
Self Diffusion ◽  
Ultra High Temperature

The IV and V group transition metals borides, carbides, and nitrides are widely known as ultra-high temperature ceramics (UHTCs), owing to their high melting point above 2500°C. These ceramics possess outstanding physical and engineering properties, such as high hardness and strength, low electrical resistivity and good chemical inertness which make them suitable structural materials for applications under high heat fluxes. Potential applications include aerospace manufacturing; for example sharp leading edge parts on hypersonic atmospheric re-entry vehicles, rocket nozzles, and scramjet components, where operating temperatures can exceed 3000°C. The extremely high melting point and the low self-diffusion coefficient make these ceramics very difficult to sinter to full density: temperatures above 2000°C and the application of pressure are necessary conditions. However these processing parameters lead to coarse microstructures, with mean grain size of the order of 20 µm and trapped porosity, all features which prevent the achievement of the full potential of the thermo-mechanical properties of UHTCs. Several activities have been performed in order to decrease the severity of the processing conditions of UHTCs introducing sintering additives, such as metals, nitrides, carbides or silicides. In general the addition of such secondary phases does decrease the sintering temperature, but some additives have some drawbacks, especially during use at high temperature, owing to their softening and the following loss of integrity of the material. In this chapter, composites based on borides and carbides of Zr, Hf and Ta were produced with addition of MoSi2 or TaSi2. These silicides were selected as sintering aids owing to their high melting point (>2100°C), their ductility above 1000°C and their capability to increase the oxidation resistance. The microstructure of fully dense hot pressed UHTCs containing 15 vol% of MoSi2 or TaSi2, was characterized by x-ray diffraction, scanning, and transmission electron microscopy. Based on microstructural features detected by TEM, thermodynamical calculations, and the available phase diagrams, a densification mechanism for these composites is proposed. The mechanical properties, namely hardness, fracture toughness, Young’s modulus and flexural strength at room and high temperature, were measured and compared to the properties of other ultra-high temperature ceramics produced with other sintering additives. Further, the microstructural findings were used to furnish possible explanations for the excellent high temperature performances of these composites.

Microstructure and Mechanical Properties of Mg-Y Alloys

2011 ◽  
Vol 239-242 ◽  
pp. 352-355
Author(s):  
Quan An Li ◽  
Qing Zhang ◽  
Chang Qing Li ◽  
Yao Gui Wang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Rare Earth ◽  
Melting Point ◽  
Room Temperature ◽  
Optimum Combination ◽  
High Melting ◽  
High Melting Point ◽  
Microstructure And Mechanical Properties ◽  
The Matrix

The effects of 2-12 wt.% Y addition on the microstructure and mechanical properties of as-cast Mg-Y binary alloys have been investigated. The results show that proper content of rare earth Y addition can obviously refine the grains and form high melting point Mg24Y5 phases in the matrix, and improve the microstructure and mechanical properties of the alloys. At room temperature, the optimum combination of ultimate tensile strength and elongation, 195MPa and 7.5%, is obtained in Mg-10 wt.% Y alloy.

Mechanical properties of high melting point waxes

1967 ◽  
Vol 3 (10) ◽  
pp. 716-719
Author(s):  
T. G. Semenova ◽  
N. S. Lisitsyna ◽  
A. V. Poplavskaya
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
High Melting ◽  
High Melting Point

Effects of Ca on Microstructure and Mechanical Properties of Mg-5.5Al-1.2Y Alloy

2012 ◽  
Vol 198-199 ◽  
pp. 216-219
Author(s):  
Wen Jian Liu ◽  
Quan An Li ◽  
Zhi Chen ◽  
Xiao Jie Song
Keyword(s):  
Mechanical Properties ◽  
Elevated Temperature ◽  
Melting Point ◽  
Magnesium Alloy ◽  
Intermetallic Compounds ◽  
High Melting ◽  
High Melting Point ◽  
Dramatic Decrease ◽  
Microstructure And Mechanical Properties ◽  
Ca Addition

The microstructure and mechanical properties of aged Mg-5.5Al-1.2Y magnesium alloy with Ca addition are investigated. The results show that with 1.0wt.% Ca addition, the phase of Al2Y is refined obviously and the phase of Mg17Al12 has a dramatic decrease in number. And, high melting point intermetallic compounds Al2Ca and Al4Ca are formed. Meanwhile, the β-Mg17Al12 phase become more dispersed. After 1.0wt.% Ca addition, the mechanical properties of the alloy at room and elevated temperature are improved.

Structure and mechanical properties of spark plasma sintered TiN-based nanocomposites

2012 ◽  
Vol 57 (3) ◽  
pp. 853-858 ◽  
Author(s):  
O. Zgalat-Lozynskyy ◽  
M. Herrmann ◽  
A. Ragulya ◽  
M. Andrzejczuk ◽  
A. Polotai
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Titanium Nitride ◽  
Spark Plasma Sintering ◽  
High Melting ◽  
High Melting Point ◽  
Linear Heating ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
Nanocomposite Powders

Consolidation of commercially available titanium nitride nanostructured powder as well as nanocomposite powders in the Si3N4-TiN and TiN-TiB2 systems have been performed by Spark Plasma Sintering (SPS) in the temperature range from 1200°C to 1550°C. The effect of non-linear heating and loading regimes on high melting point nanocomposites consolidation has been investigated.

Mechanical Properties and Microstructure of SS400 Friction Stir Welds Pursuant to Welding Distance

2011 ◽  
Vol 399-401 ◽  
pp. 273-276
Author(s):  
Kwang Jin Lee ◽  
Hyun Kuk Park ◽  
Sang Hyuk Kim ◽  
Hyun Kuk Park ◽  
Ik Hyun Oh
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Abrasion Resistance ◽  
Industrial Development ◽  
Welding Process ◽  
High Strength ◽  
High Melting ◽  
High Melting Point ◽  
Friction Stir ◽  
Metallic Compounds

FSW have advantage as defect such as porosity, metallic compounds decrease than other welding process. So, FSW was researched about low melting point materials. However, welding of high melting point and high strength materials attract attention because of high mechanical properties was needed due to industrial development. In this study, FSW is enforced using the kind of high melting point materials as SS400(SPHC). However, the tool must have super heat-resisting and abrasion resistance. So, WC-X%Co tool was manufactured by SPS method. The result, welding is successfully practice using WC-X%Co tool to 50m without fracture of tool.

Effects of Nd on Mechanical Properties of Magnesium Alloy AZ91

2014 ◽  
Vol 488-489 ◽  
pp. 256-259
Author(s):  
Hui Zhen Jiang ◽  
Quan An Li ◽  
Xiao Ya Chen ◽  
Lei Lei Chen
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Melting Point ◽  
Magnesium Alloy ◽  
Room Temperature ◽  
High Melting ◽  
High Melting Point ◽  
Alloy Az91 ◽  
Magnesium Alloy Az91

The effect of Nd on the mechanical properties of magnesium alloy AZ91 has been studied. The results show that the addition of 1wt.%Nd can refine the grain size, cause the formation of high melting point Al2Nd phase and reduce the amount of β-Mg17Al12 phase. and enhance the mechanical properties of magnesium alloy AZ91 at room temperature and 150°C.

scholarly journals High Temperature Ceramic Materials

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2031
Author(s):  
Shaowei Zhang
Keyword(s):  
Mechanical Properties ◽  
Thermal Properties ◽  
High Temperature ◽  
Melting Point ◽  
Erosion Resistance ◽  
Ceramic Materials ◽  
High Melting ◽  
High Melting Point ◽  
Physiochemical Properties ◽  
Industrial Sectors

Thanks to their superior physiochemical properties such as high melting point, excellent mechanical properties, good thermal properties, and great corrosion/erosion resistance, high temperature ceramic materials (HTCM) find applications in a broad range of demanding areas or industrial sectors, e [...]

scholarly journals Chromium-Based Alloys Strengthened by Ordered Phase Precipitation for Gas Turbine Applications

2011 ◽  
Vol 278 ◽  
pp. 569-574 ◽  
Author(s):  
Didier Locq ◽  
Pierre Caron ◽  
Catherine Ramusat ◽  
Rémy Mévrel
Keyword(s):  
Mechanical Properties ◽  
Melting Point ◽  
Gas Turbine ◽  
Oxidation Resistance ◽  
Alumina Scale ◽  
High Melting ◽  
Phase Precipitation ◽  
High Melting Point ◽  
Ti Alloys ◽  
Aero Engine

Chromium-based alloys are considered as potential candidates for applications in hot sections of aero engine turbines due to their high melting point and their moderate density. Some ternary (Cr-Ni-Al) and quaternary (Cr-Ni-Al-Ti) alloys have been designed with the aim to induce precipitation of ordered strengthening precipitates and to promote the formation of a protective alumina scale. These alloys were cast using various techniques in order to assess their microstructural and mechanical properties and their oxidation resistance.

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