Reinforcement stresses during deformation of sphere- and particulate-reinforced Al-matrix composites
- Oxford Univ. (United Kingdom). Dept. of Materials
- Polytechnic Univ. of Madrid (Spain). Dept. of Materials Science
Recent experimental results showed that reinforcement fracture is very often the dominant damage mechanism during ambient temperature deformation of discontinuously reinforced Al-matrix composites (DRAC). The reinforcements are broken by cracks perpendicular to the loading axis, and the fraction of broken reinforcements increases during plastic deformation as the load transferred from the matrix to the ceramic particulates increases. This process continues until a criteria fraction of broken reinforcements is reached, and then fracture takes place suddenly by a ductile mechanism involving localized necking of the intervoid matrix. The rate of reinforcement fracture depends on the strength of the ceramic reinforcements and on the stresses acting on them, and the modeling of the processes of damage accumulation in DRAC requires the knowledge of both. In particular, the stresses acting on the reinforcements during monotonic tensile deformation are a function of the applied strain, of the matrix and reinforcement properties, and of the volume fraction and shape of the ceramic reinforcements. A parametrical study is presented in this article of the influence of these factors on the stress acting on the reinforcements. The numerical results covered the whole range of matrix strengths which are typical in DRAC and were fitted to simple analytical expressions to facilitate their use by other researchers.
- Sponsoring Organization:
- USDOE
- OSTI ID:
- 207700
- Journal Information:
- Metallurgical Transactions, A, Vol. 27, Issue 2; Other Information: PBD: Feb 1996
- Country of Publication:
- United States
- Language:
- English
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