Microwave Reaction Sintering of Tungsten Carbide Cobalt Hardmetals

1996 ◽  
Vol 430 ◽  
Author(s):  
T. Gerdes ◽  
M. Willert-Porada ◽  
K. Rödiger ◽  
K. Dreyer
Keyword(s):  
Mechanical Properties ◽  
Tungsten Carbide ◽  
Microwave Field ◽  
Phase Reaction ◽  
Reaction Sintering ◽  
Densification Behavior ◽  
Fine Grained ◽  
Microwave Reaction ◽  
Liquid Phase Reaction ◽  
Processing Cycle

AbstractMicrowave reaction sintering of tungsten- carbon-, cobalt mixtures is described as a method that combines the liquid phase reaction sintering of tungsten carbide cobalt hardmetals with the enhanced densification behavior of hardmetals in the microwave field. Starting with green parts composed of W-, Co- powder, soot as carbon source and with varying amount of additives a dense and extremely fine grained hardmetal can be obtained in one pressureless microwave reaction sintering step.By this method hardmetals with improved mechanical properties can be obtained in a drastically simplified processing cycle, without time consuming steps such as carburizing and milling.

Microstructure and Mechanical Properties of Mo2FeB2 Based Cermets with/without Nb Addition

2017 ◽  
Vol 872 ◽  
pp. 56-60 ◽  
Author(s):  
De Qing Ke ◽  
Ying Jun Pan ◽  
Yuan Yuan Xu ◽  
Lin Yang ◽  
Run Wu
Keyword(s):  
Mechanical Properties ◽  
Grain Size ◽  
Rupture Strength ◽  
Phase Reaction ◽  
Reaction Sintering ◽  
Densification Behavior ◽  
Microstructural Characteristics ◽  
Nb Content ◽  
Nb Addition ◽  
Liquid Phase Reaction

Four series of Mo2FeB2 based cermets with different Nb content between 0 and 6 wt.% had been successfully fabricated by liquid phase reaction sintering (LPRS). The densification behavior, microstructural characteristics and mechanical properties of Mo2FeB2 based cermets were investigated. The result shows that with the increase of Nb content, the grain size decreased, but more pores formed. Meanwhile, the hardness and transverse rupture strength both be increased first and then decreased. Mo2FeB2 based cermets doped with 4 wt.% Nb content have the highest hardness and TRS of HRA 90.6 and 1970 MPa.

Reaction Sintering of Mg2Si Intermetallic Compound by Microwave Irradiation

2012 ◽  
Vol 512-515 ◽  
pp. 1683-1686
Author(s):  
Chang Kun Du ◽  
Shu Cai Zhou
Keyword(s):  
Solid State ◽  
Intermetallic Compound ◽  
Microwave Field ◽  
Phase Reaction ◽  
Reaction Sintering ◽  
Green Density ◽  
Power Setting ◽  
Lower Heating Rate ◽  
Lower Heating ◽  
Heating Profile

In order to reduce the oxidizing and volatilizing caused by Mg element in the traditional methods for synthesizing Mg2Si compounds, solid state phase reaction at low temperature was introduced by microwave field. XRD was used to characterize the powders. At the same time, the influences of parameters during the synthesis processing were discussed. The results suggest that the heating profile is also dependent on the initial green density and higher green density provides lower heating rate while power setting are fixed and the oxidation of Mg can be rest rained by changing microwave heating programs. It was found that high purity Mg2Si intermetallic compound can be obtained with excessive content of 8at% Mg from the stoichiometric Mg2Si, 853K and 30min

Collective processes in liquid-phase reaction sintering

2010 ◽  
Vol 49 (3-4) ◽  
pp. 141-146 ◽  
Author(s):  
V. P. Solntsev ◽  
V. V. Skorokhod ◽  
T. A. Solntseva
Keyword(s):  
Liquid Phase ◽  
Phase Reaction ◽  
Reaction Sintering ◽  
Collective Processes ◽  
Liquid Phase Reaction

Reaction sintering and mechanical properties of B4C with addition of ZrO2

2000 ◽  
Vol 15 (11) ◽  
pp. 2431-2436 ◽  
Author(s):  
Hae-Won Kim ◽  
Young-Hag Koh ◽  
Hyoun-Ee Kim
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Flexural Strength ◽  
Elevated Temperatures ◽  
Applied Pressure ◽  
Sintering Behavior ◽  
Reaction Sintering ◽  
Densification Behavior ◽  
High Relative Density ◽  
Full Densification

The effect of ZrO2 addition on sintering behavior and mechanical properties of both hot-pressed and pressureless-sintered B4C was investigated. The addition of ZrO2 improved the densification behavior of B4C remarkably via a reaction with the B4C to form ZrB2 at elevated temperatures. When B4C was densified at 2000 °C by hot pressing, only a small amount (approximately 2.5 vol%) of ZrO2 was necessary to achieve a full densification. Excellent mechanical properties (hardness, elastic modulus, flexural strength, and fracture toughness) were observed in those specimens. As the amount of ZrO2 was increased further, the mechanical properties were reduced, except for the fracture toughness, apparently due to the formation of too much ZrB2 in the specimen. Without the applied pressure, larger amounts of ZrO2 should be added to obtain a body with high relative density. When the B4C was sintered at 2175 °C with addition of 10 vol% ZrO2, the specimen has a density higher than 95% of the theoretical, and hardness and flexural strength of 25 GPa and 400 MPa, respectively.

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