Simultaneous sintering of low-melting-point Mg with high-melting-point Ti via a novel one-step high-pressure solid-phase sintering strategy

2021 ◽  
Vol 858 ◽  
pp. 158344
Author(s):  
Xuecheng Cai ◽  
Shuaijun Ding ◽  
Zhongjie Li ◽  
Xin Zhang ◽  
Kangkang Wen ◽  
...  
Keyword(s):  
High Pressure ◽  
Melting Point ◽  
Solid Phase ◽  
High Melting ◽  
High Melting Point ◽  
One Step

scholarly journals Microstructural Characteristics of AlSi9Cu3(Fe) Alloy with High Melting Point Elements

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1278 ◽  
Author(s):  
Tomasz Szymczak ◽  
Grzegorz Gumienny ◽  
Leszek Klimek ◽  
Marcin Goły ◽  
Tadeusz Pacyniak
Keyword(s):  
High Pressure ◽  
Melting Point ◽  
Base Alloy ◽  
Die Casting ◽  
Area Fraction ◽  
High Melting ◽  
High Melting Point ◽  
High Pressure Die Casting ◽  
Pressure Die Casting ◽  
3Si2 Phase

The paper presents the results of microstructure tests of EN AC-46000 hypoeutectic Al–Si alloy with and without high-melting-point elements: chromium, molybdenum, vanadium, and tungsten. The above-mentioned elements were used individually or simultaneously in various combinations. The tested castings were made using two technologies: shell molding and high pressure die casting (HPDC). Using X-ray diffraction and microanalysis of the chemical composition an attempt to determine the phase structure of the tested alloy was made. It has been shown that the microstructure of the base alloy consists of dendrites of α(Al) solid solution and complex eutectic mixtures: ternary α(Al) + Al15(Fe,Mn)3Si2 + β(Si) and quaternary α(Al) + Al2Cu + AlSiCuFeMgMnNi + β(Si). High-melting point elements, regardless of the combination used, attach mainly to intermetallic phases rich in Fe and form the Al15(Fe,Mn,M)3Si2 phase, where M is any high melting point element or a combination of such elements. It has been shown that the area fraction of the above-mentioned phase increases with increasing content of high melting point elements. A greater area fraction of the Al15(Fe,Mn,M)3Si2 phase in the casting from the shell mold in relation to the high pressure die casting has been also found.

The Effect of Different Preparation Methods on the Microstructure of Zirconium Diboride Ceramic Powder

2012 ◽  
Vol 624 ◽  
pp. 9-12
Author(s):  
Yan Yan Wang ◽  
Chang Ling Zhou ◽  
Chong Hai Wang ◽  
Rui Xiang Liu ◽  
Xi Zhu Lin ◽  
...  
Keyword(s):  
Melting Point ◽  
Carbothermic Reduction ◽  
Solid Phase ◽  
Ceramic Powder ◽  
High Hardness ◽  
Zirconium Diboride ◽  
High Melting ◽  
High Melting Point ◽  
Preparation Methods ◽  
Median Diameter

The melting point of zirconium diboride is up to 3245 ° C. It is concerned widespread as a high-temperature structural materials because of high melting point, high hardness, excellent electrical conductivity and good thermal conductivity. In this paper zirconium diboride powder was prepared by the carbothermic reduction and precursor pyrolysis. XRD, SEM and DTA were used to characterize the performance of the two powders. Results show that the median diameter of zirconium diboride powder prepared by solid phase is about 6μm, round in shape, is not conducive to the sintering. Zirconium diboride powder prepared by precursor pyrolysis is massive, which is deposited by the layers of zirconium diboride crystals.

scholarly journals Characteristics of Al-Si Alloys with High Melting Point Elements for High Pressure Die Casting

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4861
Author(s):  
Tomasz Szymczak ◽  
Grzegorz Gumienny ◽  
Leszek Klimek ◽  
Marcin Goły ◽  
Jan Szymszal ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Melting Point ◽  
Crystallization Process ◽  
Die Casting ◽  
Hypoeutectic Alloy ◽  
High Melting ◽  
High Melting Point ◽  
High Pressure Die Casting ◽  
Pressure Die Casting

This paper is devoted to the possibility of increasing the mechanical properties (tensile strength, yield strength, elongation and hardness) of high pressure die casting (HPDC) hypoeutectic Al-Si alloys by high melting point elements: chromium, molybdenum, vanadium and tungsten. EN AC-46000 alloy was used as a base alloy. The paper presents the effect of Cr, Mo, V and W on the crystallization process and the microstructure of HPDC aluminum alloy as well as an alloy from the shell mold. Thermal and derivative analysis was used to study the crystallization process. The possibility of increasing the mechanical properties of HPDC hypoeutectic alloy by addition of high-melting point elements has been demonstrated.

CRM MOLYBDENUM-50 RHENIUM

Alloy Digest ◽  
1970 ◽  
Vol 19 (12) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Melting Point ◽  
Physical Properties ◽  
Heat Treating ◽  
Electrical Contacts ◽  
High Melting ◽  
High Melting Point ◽  
Temperature Performance

Abstract CRM MOLYBDENUM-50 RHENIUM is a high-melting-point alloy for applications such as electronics tube components, electrical contacts, thermionic converters, thermocouples, heating elements and rocket thrusters. All products are produced by powder metallurgy. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Mo-11. Producer or source: Chase Brass & Copper Company Inc..

CRM RHENIUM

Alloy Digest ◽  
1970 ◽  
Vol 19 (8) ◽  
Keyword(s):  
Corrosion Resistance ◽  
High Temperature ◽  
Powder Metallurgy ◽  
Melting Point ◽  
Heat Treating ◽  
Electrical Contacts ◽  
High Melting ◽  
High Melting Point ◽  
Temperature Performance ◽  
Commercially Pure

Abstract CRM RHENIUM is a commercially pure, high-melting-point metal for applications such as electronics tube components, electrical contacts, thermionic converters, thermocouples, heating elements and rocket thrusters. All products are produced by powder metallurgy. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties as well as creep. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Re-1. Producer or source: Chase Brass & Copper Company Inc..

WIELAND DURO TUNGSTEN

Alloy Digest ◽  
2020 ◽  
Vol 69 (10) ◽  
Keyword(s):  
Melting Point ◽  
Physical Properties ◽  
Tensile Properties ◽  
Modulus Of Elasticity ◽  
Radiation Shielding ◽  
High Melting ◽  
High Modulus ◽  
High Melting Point ◽  
Structural Applications ◽  
Very High

Abstract Wieland Duro Tungsten is unalloyed tungsten produced from pressed-and-sintered billets. The high melting point of tungsten makes it an obvious choice for structural applications exposed to very high temperatures. Tungsten is used at lower temperatures for applications that can benefit from its high density, high modulus of elasticity, or radiation shielding capability. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on machining. Filing Code: W-34. Producer or source: Wieland Duro GmbH.

Facile synthesis of high‐melting point spherical TiC and TiN powders at low temperature

2019 ◽  
Vol 103 (2) ◽  
pp. 889-898 ◽  
Author(s):  
Maoqiao Xiang ◽  
Miao Song ◽  
Qingshan Zhu ◽  
Chaoquan Hu ◽  
Yafeng Yang ◽  
...  
Keyword(s):  
Melting Point ◽  
Low Temperature ◽  
High Melting ◽  
High Melting Point ◽  
Facile Synthesis

Screening of high melting point phase change materials (PCM) in solar thermal concentrating technology based on CLFR

Solar Energy ◽  
2005 ◽  
Vol 79 (3) ◽  
pp. 332-339 ◽  
Author(s):  
Akira Hoshi ◽  
David R. Mills ◽  
Antoine Bittar ◽  
Takeo S. Saitoh
Keyword(s):  
Melting Point ◽  
Phase Change ◽  
Phase Change Materials ◽  
Solar Thermal ◽  
High Melting ◽  
High Melting Point

Observation of Rheed Intensity Oscillations During PbSe/CaF2/Si(111) MBE

1996 ◽  
Vol 441 ◽  
Author(s):  
W. K. Liu ◽  
X. M. Fang ◽  
P. J. McCann ◽  
M. B. Santos
Keyword(s):  
Activation Energy ◽  
Melting Point ◽  
Substrate Temperature ◽  
High Melting ◽  
Arrhenius Behavior ◽  
High Activation ◽  
High Melting Point ◽  
Mbe Growth ◽  
Sublimation Energy ◽  
Initial Nucleation

AbstractRHEED intensity oscillations observed during MBE growth of CaF2 on Si(111) and PbSe on CaF2/Si(111) are presented. The effects of substrate temperature and initial nucleation procedure are investigated. Strong temporal oscillations of the specular beam intensity are found to be most readily observed at temperatures below 200°C for both CaF2 and PbSe. Growth rates measured as a function of cell temperatures exhibit Arrhenius behavior with activation energies of 5.0 eV and 1.93 eV for CaF2 and PbSe, respectively. The relatively high activation energy obtained for CaF2 is consistent with the high melting point and sublimation energy of ionic fluorides.

A study of pest oxidation in polycrystalline MoSi2

1992 ◽  
Vol 7 (10) ◽  
pp. 2747-2755 ◽  
Author(s):  
C.G. McKamey ◽  
P.F. Tortorelli ◽  
J.H. DeVan ◽  
C.A. Carmichael
Keyword(s):  
High Temperature ◽  
Melting Point ◽  
Stoichiometric Ratio ◽  
Low Density ◽  
High Melting ◽  
Phase Boundaries ◽  
High Melting Point ◽  
Good Oxidation Resistance ◽  
Intermediate Temperature Range ◽  
Physical Defects

MoSi2 is a promising high-temperature material with low density (6.3 g/cm3), high melting point (2020 °C), and good oxidation resistance at temperatures to about 1900 °C. However, in the intermediate temperature range between 400 and 600 °C, it is susceptible to a “pest” reaction which causes catastrophic disintegration by a combination of oxidation and fracture. In this study, we have used polycrystalline MoSi2, produced by arc-casting of the pure elements and by cold and hot pressing of alloy powders, to characterize the pest reaction and to determine the roles of composition, grain or phase boundaries, and physical defects on the oxidation and fracture of specimens exposed to air at 500 °C. It was found that pest disintegration occurs through transport of oxygen into the interior of the specimen along pre-existing cracks and/or pores, where it reacts to form MoO3 and SiO2. The internal stress produced during the formation of MoO3 results in disintegration to powder. Near the stoichiometric ratio, the susceptibility to pest disintegration increases with increasing molybdenum content and with decreasing density. Silicon-rich alloys were able to form protective SiO2 and showed no indication of disintegration, even at densities as low as 60%.

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