Title: Effects of Ni-doping mode on microstructure and mechanical properties of alumina/Ni composites

Authors: Mao-xiang Jing, Xiang-qian Shen, Wang-xing Li, Dong-hong Li

Addresses: School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China; Zhengzhou Research Institute of Chalco, Zhengzhou 450041, China. ' School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China. ' Zhengzhou Research Institute of Chalco, Zhengzhou 450041, China. ' School of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013, China; Zhengzhou Research Institute of Chalco, Zhengzhou 450041, China

Abstract: Alumina-based cermets with Ni doping modes of intergranular, intragranular and mixture of both were prepared by hot press-sintering Ni-coated alumina, alumina-coated Ni and co-precipitate powders respectively. The densification process of the cermets from these three Ni/alumina powders was mainly influenced by Ni contents, sintering temperature, and precipitation process of precursor powders. The Ni phase at low contents with small particles located on the interfaces promoted the densification process due to a high reactivity and at high contents to some extent restrained the densification rate while reduced coarsening of alumina grains at high sintering temperatures. The Ni-doping modes could lead to a change in the fracture approach of alumina matrix and improvements of mechanical properties.

Keywords: Ni-doped alumina cermets; hot press sintering; fracture; densification; microstructure; nitrogen doping; mechanical properties; composites.

DOI: 10.1504/IJMPT.2009.024666

International Journal of Materials and Product Technology, 2009 Vol.34 No.3, pp.342 - 351

Published online: 14 Apr 2009 *

Full-text access for editors Full-text access for subscribers Purchase this article Comment on this article