Title : ( Investigation of in-situ synthesis and consolidation of NiAl–Al2O3 composites by reactive spark plasma sintering process using mechanically activated reaction )
Authors: Maryam Beyhaghi , Ali Reza Kiani Rashid , Mehrdad Kashefi Torbati , Jalil Vahdati Khaki , Stefan Jonsson ,
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Abstract
In the present study, NiAl/Al2O3 in-situ composites are fabricated from nickel oxide, nickel and aluminum by utilization of mechanical activation for 1 hour and 4.5 hours and then spark plasma sintering (SPS). Both thermite reaction and consolidation of reactant materials are fulfilled during the SPS process. In composites made from 4.5 hour ball milled powder, effects of different SPS parameters, such as temperature (950°C, 1000°C and 1050°C), pressure (65 MPa and 90 MPa) and types of heating method (resistance heating of graphite die, combined resistance heating of sample and graphite die) on microstructure and hardness of fabricated intermetallic composites (IMCs) are investigated. X-ray diffractometry results show that all samples are composed of NiAl and Al2O3 phases. A mechanism for reaction and shrinkage during SPS with the aid of differential thermal analysis results and recorded data by SPS apparatus is proposed. Relative density of the composites measured by the Archimedes method exceeds 99% by sintering at 1050°C. Hardness of sintered IMCs improves by increments in sintering temperature and sintering pressure. The highest hardness belongs to sample heated to 1050°C with the combined resistance heating of sample and of graphite die during SPS because of its homogenous microstructure.
Keywords
, Composites, Nickel aluminides, Alumina, Spark Plasma Sintering, Mechanical activation
@article{paperid:1045333,
author = {Beyhaghi, Maryam and Kiani Rashid, Ali Reza and Kashefi Torbati, Mehrdad and Vahdati Khaki, Jalil and Stefan Jonsson},
title = {Investigation of in-situ synthesis and consolidation of NiAl–Al2O3 composites by reactive spark plasma sintering process using mechanically activated reaction},
journal = {International Journal of Material Science Innovations},
year = {2014},
volume = {2},
number = {4},
month = {August},
issn = {2289-4063},
pages = {100--116},
numpages = {16},
keywords = {Composites; Nickel aluminides; Alumina; Spark Plasma Sintering; Mechanical activation},
}
%0 Journal Article
%T Investigation of in-situ synthesis and consolidation of NiAl–Al2O3 composites by reactive spark plasma sintering process using mechanically activated reaction
%A Beyhaghi, Maryam
%A Kiani Rashid, Ali Reza
%A Kashefi Torbati, Mehrdad
%A Vahdati Khaki, Jalil
%A Stefan Jonsson
%J International Journal of Material Science Innovations
%@ 2289-4063
%D 2014
