Crack bridging in a laminated metal matrix composite

Journal Article · Thu Sep 01 04:00:00 EDT 1994 · Scripta Metallurgica et Materialia; (United States)

DOI:https://doi.org/10.1016/0956-716X(94)90152-X· OSTI ID:7085157

Osman, T M; Singh, P M; Lewandowski, J J ^[1]

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1. Case Western Reserve Univ., Cleveland, OH (United States). Dept. of Materials Science and Engineering

Laminate structures consisting of alternating layers of reinforced and monolithic metallic alloys have been proposed as a method to enhance the fracture resistance of discontinuously reinforced metal matrix composites. One objective of producing such layered structures is to create a material which benefits from enhanced strength and stiffness without a degradation in damage tolerance. Improvements in the fracture initiation and growth toughness of 10% and 250%, respectively, have been reported for a bi-layer laminate consisting of monolithic 3003 and MB85/SiC/15p. Similarly, the fracture resistance of a tri-layer laminate containing two layers of monolithic 7093 surrounding one layer of 7093/SiC/15p was markedly greater than unlaminated 7093/SiC/15p and comparable to the monolithic 7093. These laminates are designed to utilize extrinsic toughening mechanisms on a macroscopic scale to produce stable crack propagation in materials which otherwise exhibit little crack growth resistance. Crack tunneling has been observed in the crack divider orientation of hybrid structures in which cracking occurs to a greater extent in constituent with the lower intrinsic fracture resistance. In the case of the 7093-7093/SiC/15p tri-layer laminate system, crack extension of 4.9 mm was observed in the DRA layer compared to only 1.6 mm the monolithic layers. As a result, crack growth did not occur at the same rate in easy layer and a substantial ductile ligament was present in the crack wake of the DRA material. The purpose of this study was to investigate the role of crack bridging on a macroscopic scale in laminated metal matrix composites. In particular, the following sections document initial attempts to investigate crack wake effects in laminate structures in which crack propagation does not occur simultaneously in both layers.

• OSTI ID: 7085157
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 31:5; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360603* -- Materials-- Properties
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM BASE ALLOYS
CARBIDES
CARBON COMPOUNDS
COMPOSITE MATERIALS
COPPER ALLOYS
CRACK PROPAGATION
DATA
EXPERIMENTAL DATA
FRACTURE PROPERTIES
INFORMATION
MAGNESIUM ALLOYS
MATERIALS
MECHANICAL PROPERTIES
NICKEL ADDITIONS
NICKEL ALLOYS
NUMERICAL DATA
SILICON CARBIDES
SILICON COMPOUNDS
ZINC ALLOYS
ZIRCONIUM ADDITIONS
ZIRCONIUM ALLOYS