New Equipment for Production of Super Hard Spherical Tungsten Carbide and other High-Melting Compounds Using the Method of Plasma Atomization of Rotating Billet

2017 ◽  
Vol 898 ◽  
pp. 1485-1497 ◽  
Author(s):  
V.N. Korzhyk ◽  
L.D. Kulak ◽  
V.E. Shevchenko ◽  
V.V. Kvasnitskiy ◽  
N.N. Kuzmenko ◽  
...  

In order to ensure high wear resistance of parts and tools, operating at significant dynamic loads in the extreme conditions, the layers different in their function purpose obtained using surfacing methods are widely used. In such surfacing compositions, the powders of high-melting compounds characterized by high hardness and strength, are used as a wear resistant component, for example, alloys of tungsten carbide WC + W2C (cast tungsten carbide), and as binder matrix the plastic and metal alloys are used.The great interest is the development of methods allowing producing powders of cast tungsten carbide and other high-melting-point materials of uniform composition, characterized by a high sphericity of the particles and having higher physical-mechanical properties. The spherical tungsten carbide was produced by plasma atomization of rotating billet. The universal installation for production of super-hard spherical tungsten carbide and other high-melting-point compounds by plasma atomization of rotating billets was designed for industrial application. The results showed that the application of the technology of plasma rotary atomization of rotation billet to obtain granules of powders of high-melting-point materials was promising, in particular tungsten carbide with sphericity over 90%, microhardness HV0.1 more than 3000 kg / mm2 characterized by high flow ability more than 7.5 s/ 50 g. Due to the use of new materials and innovative design and technological solutions the high reliability, maximum interval of technical service, high resource of operating units and executing mechanism of the equipment were ensured. Due to the use of new high-power plasma system with power supply source with high efficiency coefficient and improved dynamic characteristics, the system of preliminary heating of billets, innovative gas systems, high performance vacuum system, the developed universal system for the production of granules of powders of high-melting-point material were also applicable for the manufacture of spherical powders of metals and alloys, including highly active, and provided lower costs of products (powder) with an increased productivity, economic efficiency of the atomization process and reduced the impact of atomization process on the environment.

Alloy Digest ◽  
1970 ◽  
Vol 19 (12) ◽  

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..


Alloy Digest ◽  
1970 ◽  
Vol 19 (8) ◽  

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..


Alloy Digest ◽  
2020 ◽  
Vol 69 (10) ◽  

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.


2019 ◽  
Vol 103 (2) ◽  
pp. 889-898 ◽  
Author(s):  
Maoqiao Xiang ◽  
Miao Song ◽  
Qingshan Zhu ◽  
Chaoquan Hu ◽  
Yafeng Yang ◽  
...  

Solar Energy ◽  
2005 ◽  
Vol 79 (3) ◽  
pp. 332-339 ◽  
Author(s):  
Akira Hoshi ◽  
David R. Mills ◽  
Antoine Bittar ◽  
Takeo S. Saitoh

1996 ◽  
Vol 441 ◽  
Author(s):  
W. K. Liu ◽  
X. M. Fang ◽  
P. J. McCann ◽  
M. B. Santos

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.


1992 ◽  
Vol 7 (10) ◽  
pp. 2747-2755 ◽  
Author(s):  
C.G. McKamey ◽  
P.F. Tortorelli ◽  
J.H. DeVan ◽  
C.A. Carmichael

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%.


2007 ◽  
Vol 336-338 ◽  
pp. 1203-1206 ◽  
Author(s):  
Metin Gürü ◽  
M. Korçak ◽  
Süleyman Tekeli ◽  
Ahmet Güral

The properties of ceramic-metal (Cermet) composites as tensile strength, hardness and resistance to corrosion and high temperature are superior than ceramics and metals. Because of the enhanced characteristics of cermets, they are commonly used in various applications and industries. The main objective of this study is to produce a cheap, easy produced, strong and high corrosion resistant composite material. For these purposes, zinc is used for its natural capacity against corrosion, low density, low melting point and softness. Magnesium aluminates spinel oxide (MgAl2O4) is chosen because of its high melting point and low density. Fly ash is a waste from coal power plant having puzzolanic properties. In this study, the effect of various amounts of zinc and fly ash addition on density and hardness behaviour of zinc-based MgAl2O4 composites was investigated. The experimental results showed that zinc and fly ash addition improved the hardness behavior of zincbased MgAl2O4 composite.


2021 ◽  
Vol 858 ◽  
pp. 158344
Author(s):  
Xuecheng Cai ◽  
Shuaijun Ding ◽  
Zhongjie Li ◽  
Xin Zhang ◽  
Kangkang Wen ◽  
...  

2021 ◽  
Vol 22 (7) ◽  
Author(s):  
C. Lagan ◽  
J. E. Huckle ◽  
J. M. Katz ◽  
B. Khorsand ◽  
D. Daurio ◽  
...  

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