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Title: Crack growth and closure effects under far-field cyclic compression in a SiC-whisker-reinforced 2124 aluminum composite

Journal Article · · Scripta Metallurgica et Materialia; (United States)
 [1];  [2];  [3]
  1. Changwon National Univ. (Korea, Republic of)
  2. Research Inst. of Industrial Science and Technology, Pohang (Korea, Republic of)
  3. Pohang Inst. of Science and Technology (Korea, Republic of)

In this study, cyclic compression fatigue tests were carried out on CT-type specimens of an aluminum matrix composite reinforced with SiC whiskers. The material used in this study was a 2124 Al-SiC[sub w] composite, manufactured by power metallurgy techniques and containing 15 v/o reinforcing SiC whisker. The crack closure induced by crack-face roughness in the wake region is found to be an important factor in limiting total fatigue crack growth distance in a 2124 Al-SiC[sub w] composite under cyclic compression. The critical saturation crack length in cyclic periodic compression loading can be controlled by compressive overload application, which decreases the crack-face roughness; here, a fatigue crack of 0.41 mm in length was obtained under cyclic compression. The tendency for the tension fatigue crack to bypass SiC whiskers microscopically and whisker-rich regions macroscopically leaves very rough features on fracture surfaces of the composite. However, most compression-fatigued fracture surfaces are found to be relatively flat, except around the crack tip region, which has an appearance (growth mechanism) similar to the tension-fatigued region.

OSTI ID:
6514822
Journal Information:
Scripta Metallurgica et Materialia; (United States), Vol. 28:7; ISSN 0956-716X
Country of Publication:
United States
Language:
English