Karak, S K and Dutta Majumdar, Jyotsna and Lojkowski, W and Michalski, A and Ciupinski, L and Kurzydlowski, K J and Manna, Indranil (2012) Microstructure and mechanical properties of nano-Y2O3 dispersed ferritic steel synthesized by mechanical alloying and consolidated by pulse plasma sintering. Philosophical Magazine, 92 (5). pp. 516-534. ISSN 1478-6435

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Abstract

Ferritic steel with compositions 83.0Fe-13.5Cr-2.0Al-0.5Ti (alloy A), 79.0Fe-17.5Cr-2.0Al-0.5Ti (alloy B), 75.0Fe-21.5Cr-2.0Al-0.5Ti (alloy C) and 71.0Fe-25.5Cr-2.0Al-0.5Ti (alloy D) (all in wt%) each with a 1.0wt% nano-Y2O3 dispersion were synthesized by mechanical alloying and consolidated by pulse plasma sintering at 600, 800 and 1000 degrees C using a 75-MPa uniaxial pressure applied for 5 min and a 70-kA pulse current at 3Hz pulse frequency. X-ray diffraction, scanning and transmission electron microscopy and energy disperse spectroscopy techniques have been used to characterize the microstructural and phase evolution of all the alloys at different stages of mechano-chemical synthesis and consolidation. Mechanical properties in terms of hardness, compressive strength, yield strength and Young's modulus were determined using a micro/nano-indenter and universal testing machine. All ferritic alloys recorded very high levels of compressive strength (850-2850 MPa), yield strength (500 1556 MPa), Young's modulus (175 250 GPa) and nanoindentation hardness (9.5-15.5 GPa), with up to 1-1.5 times greater strength than other oxide dispersion-strengthened ferritic steels (<1200 MPa). These extraordinary levels of mechanical properties can be attributed to the typical microstructure of uniform dispersion of 10-20-nm Y2Ti2O7 or Y2O3 particles in a high-alloy ferritic matrix.

Item Type:	Article
Uncontrolled Keywords:	Nano-Y2O3 dispersed ferritic steel; Mechanical alloying; Microstructure; mechanical property; pulse plasma sintering
Subjects:	Microstructure and Characterization Engineering Materials
Divisions:	UNSPECIFIED
Depositing User:	Bidhan Chaudhuri
Date Deposited:	01 Jun 2012 06:21
Last Modified:	06 Nov 2012 11:31
URI:	http://cgcri.csircentral.net/id/eprint/1450

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