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Architecturally modified Al-DRA composites: The effect of size and shape of the DRA rods on fracture behavior

Jamali, M ; Sharif University of Technology | 2010

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  1. Type of Document: Article
  2. DOI: 10.1007/s10853-010-4273-2
  3. Publisher: 2010
  4. Abstract:
  5. Architectural modification of aluminum matrix composites is considered as an efficient method to improve fracture toughness. Al-DRA (Al-Al/SiC/20 p) composites were fabricated via "powder extrusion-casting- ingot extrusion" route with structures similar to that of reinforced concrete, so that DRA rods were surrounded by unreinforced aluminum. The effects of variation in shape, size, and number of DRA rods on fracture behavior of Al-DRA composites were investigated. Composites containing DRA rods with hexagonal cross-section exhibited higher resistance to crack initiation and growth, in comparison to those containing circular rods. In the case of hexagonal rods, increasing the number of rods (reducing the rods' cross-section surface) led to further enhancement of fracture toughness. Fracture surface observations of all samples revealed the existence of desirable cohesion between rods and the surrounding matrix. The remained sharp and unblunted corners of hexagonal DRA rods caused stress concentration and microcrack formation upon loading. Hence, plastic deformation constraint of aluminum ligament between rods was alleviated, which, in turn, led to further energy consumption during the fracture process
  6. Keywords:
  7. Aluminum matrix composites ; Architectural modification ; Circular rods ; Efficient method ; Energy consumption ; Fracture behavior ; Fracture process ; Fracture surfaces ; Microcrack formation ; Powder extrusion ; Size and shape ; Surrounding matrix ; Aluminum ; Cracks ; Extrusion ; Fracture ; Reinforced concrete ; Stress analysis ; Stress concentration ; Fracture toughness
  8. Source: Journal of Materials Science ; Volume 45, Issue 11 , June , 2010 , Pages 2852-2861 ; 00222461 (ISSN)
  9. URL: http://link.springer.com/article/10.1007%2Fs10853-010-4273-2