Characterization of Fracture Toughness of Hybrid MMCs the Short Fiber Reinforced Metal Matrix Composites

Evaluation of fracture toughness of short fiber reinforced metal matrix composites (MMCs) becomes important for the application as structural materials. Therefore, in this study static and dynamic fracture toughness of MMCs manufactured by squeeze casting process were investigated. A number of MMCs have been tested with various matrix alloys, volume fractions, and specifically types of reinforcements. It was found that static and dynamic fracture toughness of metal matrix composites was remarkably decreased by the addition of ceramic reinforcements. Dynamic fracture toughness slightly decreased compared with static fracture toughness because of the effect of dynamic velocity under impact loading. The toughness of ceramic reinforced MMCs is controlled by a complexity interaction between the matrix alloy and reinforcement. Important properties which influence toughness include the type of reinforcement (its physical form, size), volume fraction and combination of reinforcement, and the matrix alloy. And notch fracture toughness of MMCs for simple evaluation was also discussed.

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Effect of Forging Parameters on Low Cycle Fatigue Behaviour of Al/Basalt Short Fiber Metal Matrix Composites

The Scientific World JOURNAL ◽

10.1155/2013/250513 ◽

2013 ◽

Vol 2013 ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

R. Karthigeyan ◽

G. Ranganath

Keyword(s):

Metal Matrix Composites ◽

Metal Matrix ◽

Low Cycle Fatigue ◽

Matrix Alloy ◽

Short Fiber ◽

Fatigue Properties ◽

Matrix Composites ◽

Fiber Reinforced ◽

The Matrix ◽

Fracture Damage

This paper deals with metal matrix composites (MMCs) of Al 7075 alloy containing different weight percentage (2.5, 5, 7.5, and 10) basalt short fiber reinforcement and unreinforced matrix alloy. The samples were produced by the permanent stir casting technique. The casting ingots were cut into blanks to be forged in single stage and double stage, using MN press and graphite-based lubricant. The microstructures and fatigue properties of the matrix alloy and MMC samples were investigated in the as cast state and in the single and double stage forging operations. The microstructure results showed that the forged sample had a uniform distribution of the basalt short fiber throughout the specimens. Evaluation of the fatigue properties showed that the forged samples had higher values than those of the as cast counterparts. After forging, the enhancement of the fatigue strength of the matrix alloy was so significant and high in the case of 2.5 and 5.0 wt. percentage basalt short fiber reinforced MMC, and there was no enhancement in 7.5 and 10 weight percentages short fiber reinforced MMCs. The fracture damage was mainly due to decohesion at the matrix-fiber interface.

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Continuum Damage Modeling for Dynamic Fracture Toughness of Metal Matrix Composites

Journal of Solid Mechanics and Materials Engineering ◽

10.1299/jmmp.3.931 ◽

2009 ◽

Vol 3 (7) ◽

pp. 931-942 ◽

Cited By ~ 2

Author(s):

Intaek LEE ◽

Yasuo OCHI ◽

Sungin BAE ◽

Jungil SONG

Keyword(s):

Fracture Toughness ◽

Metal Matrix Composites ◽

Dynamic Fracture ◽

Metal Matrix ◽

Dynamic Fracture Toughness ◽

Continuum Damage ◽

Matrix Composites ◽

Damage Modeling

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Damage of Short-Fiber-Reinforced Metal Matrix Composites Considering Cooling and Thermal Cycling

Journal of Engineering Materials and Technology ◽

10.1115/1.482788 ◽

1999 ◽

Vol 122 (2) ◽

pp. 203-208 ◽

Cited By ~ 20

Author(s):

Chuwei Zhou ◽

Wei Yang ◽

Daining Fang

Keyword(s):

Thermal Cycling ◽

Metal Matrix Composites ◽

Stress Drop ◽

Metal Matrix ◽

Failure Modes ◽

Short Fiber ◽

Uniaxial Tensile ◽

Matrix Composites ◽

Fiber Reinforced ◽

Matrix Damage

Mechanical properties and damage evolution of short-fiber-reinforced metal matrix composites (MMC) are studied under a micromechanics model accounting for the history of cooling and thermal cycling. A cohesive interface is formulated in conjunction with the Gurson-Tvergaard matrix damage model. Attention is focused on the residual stresses and damages by the thermal mismatch. Substantial stress drop in the uniaxial tensile response is found for a computational cell that experienced a cooling process. The stress drop is caused by debonding along the fiber ends. Subsequent thermal cycling lowers the debonding stress and the debonding strain. Micromechanics analysis reveals three failure modes. When the thermal histories are ignored, the cell fails by matrix damage outside the fiber ends. With the incorporation of cooling, the cell fails by fiber end debonding and the subsequent transverse matrix damage. When thermal cycling is also included, the cell fails by jagged debonding around the fiber tops followed by necking instability of matrix ligaments. [S0094-4289(00)01202-0]

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