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Inoculation of chromium white cast iron

Kopyciński D.

Archives of Foundry Engineering

2009

Vol. 9, iss. 1

191-194

It has been proved that an addition of boron carbide introduced as an inoculant to the chromium white cast iron changes the structure of castings. Castings after inoculation revealed a different structure with numerous grains. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

Analysis of the structure of castings made from chromium white cast iron resistant to abrasive wear

Kopyciński D.

Archives of Foundry Engineering

2009

Vol. 9, iss. 4

109-112

It has been proved that an addition of boron carbide and disintegrated steel scrap introduced as an inoculant to the chromium white cast iron changes the structure of castings. The said operation increases the number of crystallization nuclei for dendrites of the primary austenite. In this case, the iron particles act as substrates for the nucleation of primary austenite due to a similar crystallographic lattice. The more numerous are the dendrites of primary austenite and the structure more refined and the mechanical properties higher. Castings after B4C inoculation revealed a different structure of fine grained fracture. Primary precipitates of chromium carbide also appeared, reducing the mechanical properties of as-cast parts. Properly established heat treatment regime makes chromium iron castings regain their, originally high, mechanical properties.

Super-hard boron carbide/silicon carbide composites by reactive infiltration

Frage N., Prigozin H., Dariel M.P.

Inżynieria Materiałowa

2004

R. XXV, nr 3

278-279

Metal-ceramic composites based on B4C and SiC phases were obtain by infiltration of porous boron carbide preforms, enriched with free carbon, by silicon melt. Sugar as a precursor for free carbon was used. Porous boron carbide preforms with 35% porosity were infiltrated with sugar solution (100 gram sugar in 100 ml water). The sugar pyrolyse was performed at 500°C under argon. After the pyrolysis the preforms with 12 %wt. of free carbon were infiltrated with silicon at 1480°C under vacuum of 10^-4 torr. The resulted composites show homogeneous structure consisting of interconnected boron carbide and silicon carbide particles with 10%vol. of residual silicon. The hardness of the composites is about 2700HV and the elastic modulus is about 350GPa.

Ceramic composite resistor of B4C modified by TiO2 and glass phase.

Klimec E., Stobiecki T., Zaraska W.

Inżynieria Materiałowa

1998

R. XIX, nr 4

864-867

Technical progress in the manufacturing technology of composite materials resulted in arising of new generation of bulk resistors, resistant to high levels of overloads and high temperature. These resistors can be applied in extremly heavy working conditions, for instance in cooperation with ignition circuits. The resistors investigated in our research were performed on the basis of ceramic composite consisted of semiconductor boron carbide B4C as conductive phase, aluminium oxide Al2O3 and non-alkali glass as insulators and titanium dioxide TiO2. The technological procedure of the fabrication of resistors and the results of the tests, such as temperature dependence of the electrical resistance and exploitation trials, are presented.