Central Glass and Ceramic Research Institute

About: Central Glass and Ceramic Research Institute is a facility organization based out in Kolkata, West Bengal, India. It is known for research contribution in the topics: Microstructure & Sintering. The organization has 1123 authors who have published 2904 publications receiving 51519 citations.

Reactive Infiltration of Si‐Mo Alloyed Melt into Carbonaceous Preforms of Silicon Carbide

Abstract: A MoSi2/reaction-bonded SiC composite was prepared from a preform of petroleum coke and commercial SiC powders (in weight ratios of 0.5 and 0.6), following reactive infiltration of a Si-Mo melt (molybdenum concentration of 7–29 wt%) made from elemental powder. The resulting material had a relative density of >90% of the theoretical density and, on a microstructural scale, contained SiC and MoSi2, in addition to unreacted carbon and silicon. The SiC and MoSi2 boundary was smooth and sharp, with no sign of any reaction. The occasional presence of an intermediate zone between SiC and MoSi2 was detected; this zone contained silicon, iron, and aluminum, the formation of which may be related to the presence of impurities in the silicon and SiC.

Evaluation of Micromechanical Properties of Carbon/Carbon and Carbon/Carbon–Silicon Carbide Composites at Ultralow Load

Abstract: 2D carbon fiber (C-fiber)-reinforced carbon/carbon (C/C) composites were prepared by vacuum infiltration with coal-tar pitch followed by carbonization and graphitization in inert atmosphere. Liquid silicon infiltration was done in controlled atmosphere at 1600 degrees C to convert the matrix carbon of the C/C composites into silicon carbide. The 2D C/C and carbon/carbon-silicon carbide (C/C-SiC) composites had density of similar to 1.65 and similar to 2.32 g/cm3, respectively with corresponding flexural strength of similar to 70 and similar to 169 MPa, respectively. The local mechanical properties like hardness, Young's modulus, contact pressure, relative stiffness, relative spring back, and indentation energies of the two composites under different loading conditions were measured at an ultra low load of 10 mN using a nanoindentation instrument with a Berkovich indenter. The scatter in the data was treated in terms of the two-parameter Weibull statistical analysis. The maximum characteristic Young's modulus (similar to 16 GPa) and hardness (1.20 GPa) was obtained for the C/C-SiC composites in parallel direction of fabric stacking. The elastic rebounce was also the maximum (0.77) for the C/C-SiC composites when loaded in parallel direction of fabric stacking. The extent of structural anisotropy was higher in the C/C-SiC composite than that of the C/C composite.

Retention of SiC during development of SiC-MxSiyOz composites [M = Al, Zr, Mg] by reaction bonding in air

Abstract: Oxidation of SiC is a major constraint during development of metal oxide–silicon carbide composites when processed in oxygen containing environment such as in air. In the present investigation, Mg+2, Al+3 and Zr+4 hydrogels were used as a source of respective oxide and oxidation of SiC in each system was studied. A three-stage mechanism was found to be operative in Al+3 and Zr+4 systems where oxidation at the initial stages was found to be controlled by the nature of the polynuclear complexes formed on the surfaces of SiC particles. At the intermediate stage a transition from polynuclear complex to metal silicate protective layer formation changes the oxidation characteristics. Finally the metal silicates provided the ultimate protection. Mg+2 was found to be ineffective. The extent of retention of SiC in the final composites could be premonitored by controlling the amount and the nature of complexing cations.