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Title: High temperature deformation of NiAl matrix composites

Abstract

The intermetallic compound, NiAl, has many attractive properties at a high temperature structural materials. However, its lack of creep resistance prevents practical applications. Adding ceramic reinforcements, such as TiB{sub 2} particles, Al{sub 2}O{sub 3} particles or whiskers can significantly improve the strength of binary NiAl at high temperatures. However, the increase in the yield stress of the discontinuous NiAl matrix composites as compared with monolithic NiAl is difficult to explain. The purposes of this research were to understand the deformation mechanisms which cause the increase in strength achieved by adding TiB{sub 2} particles, Al{sub 2}O{sub 3} particles or whiskers to NiAl, and to recognize the principles of the deformation process in NiAl matrix composites. In order to accomplish these objectives, mechanical properties and thermal activation parameters in NiAl matrix composites with different types, shapes and sizes of reinforcements have been systematically evaluated. Microstructures and dislocation structures in NiAl matrix composites have also been thoroughly characterized before and after deformation. It was found that the size of the reinforcement had a large influence on the microstructures of the composites, and the nominal activation energies for all the composites were the same and within the range of the activation energy of self-diffusionmore » for pure NiAl. It was further concluded that the reinforcement addition only increased the non-thermally activated component of the yield stress.« less

Authors:
;  [1]
  1. Univ. of Maryland, College Park, MD (United States)
Publication Date:
OSTI Identifier:
684402
Resource Type:
Journal Article
Journal Name:
Acta Materialia
Additional Journal Information:
Journal Volume: 47; Journal Issue: 10; Other Information: PBD: 10 Aug 1999
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; MICROSTRUCTURE; CREEP; NICKEL ALLOYS; ALUMINIUM ALLOYS; TITANIUM BORIDES; ALUMINIUM OXIDES; COMPOSITE MATERIALS; DISLOCATIONS; TEMPERATURE DEPENDENCE; COMPUTERIZED SIMULATION

Citation Formats

Xu, K., and Arsenault, R.J. High temperature deformation of NiAl matrix composites. United States: N. p., 1999. Web. doi:10.1016/S1359-6454(99)00146-9.
Xu, K., & Arsenault, R.J. High temperature deformation of NiAl matrix composites. United States. doi:10.1016/S1359-6454(99)00146-9.
Xu, K., and Arsenault, R.J. Tue . "High temperature deformation of NiAl matrix composites". United States. doi:10.1016/S1359-6454(99)00146-9.
@article{osti_684402,
title = {High temperature deformation of NiAl matrix composites},
author = {Xu, K. and Arsenault, R.J.},
abstractNote = {The intermetallic compound, NiAl, has many attractive properties at a high temperature structural materials. However, its lack of creep resistance prevents practical applications. Adding ceramic reinforcements, such as TiB{sub 2} particles, Al{sub 2}O{sub 3} particles or whiskers can significantly improve the strength of binary NiAl at high temperatures. However, the increase in the yield stress of the discontinuous NiAl matrix composites as compared with monolithic NiAl is difficult to explain. The purposes of this research were to understand the deformation mechanisms which cause the increase in strength achieved by adding TiB{sub 2} particles, Al{sub 2}O{sub 3} particles or whiskers to NiAl, and to recognize the principles of the deformation process in NiAl matrix composites. In order to accomplish these objectives, mechanical properties and thermal activation parameters in NiAl matrix composites with different types, shapes and sizes of reinforcements have been systematically evaluated. Microstructures and dislocation structures in NiAl matrix composites have also been thoroughly characterized before and after deformation. It was found that the size of the reinforcement had a large influence on the microstructures of the composites, and the nominal activation energies for all the composites were the same and within the range of the activation energy of self-diffusion for pure NiAl. It was further concluded that the reinforcement addition only increased the non-thermally activated component of the yield stress.},
doi = {10.1016/S1359-6454(99)00146-9},
journal = {Acta Materialia},
number = 10,
volume = 47,
place = {United States},
year = {1999},
month = {8}
}