Accession Number:

ADA034160

Title:

Fatigue Behavior of Aluminum Alloy-30 Percent Graphite Fiber Composites,

Descriptive Note:

Corporate Author:

AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS

Personal Author(s):

Report Date:

1975-03-12

Pagination or Media Count:

35.0

Abstract:

The fatigue behavior of aluminum alloy-graphite fiber composite materials prepared by liquid-metal infiltration was determined over a range of cycle life from 10 to 10 to the 8th power to establish the SN curve and the mechanisms of fatigue. The matrix materials included aluminum alloys 6061 and 201 they were infiltrated into Thornel 50 graphite fiber from the melt, which resulted in about a 30-vol fiber composite. The specimens were of circular cross section with a minimum diameter of approx. 4mm. The experimental conditions included sinusoidal loading at room temperature with a stress ratio of 0.1 and cyclic frequencies ranging from 10 to 30 Hz. The SN behavior of these materials is compared with prepared by hot-pressing. The SN curves for all aluminum composites other composite fatigue data reported in the literature, including 6061 A1-25 boron and aluminum-graphite composites compared are more or less parallel in the range from 100000 to 10 to the 7th power cycles. The fatigue strength of the 6061 alloy-graphite composite produced by liquid-metal infiltration is approx. 13 greater than the 201 alloy composite and 50 greater than the hot-pressed aluminum-graphite composite. Scanning electron fractography of the fracture surfaces indicates the fatigue fracture mode depends upon the stress level in the composite and is controlled by initiation and propagation of cracks within the matrix. Author

Subject Categories:

  • Properties of Metals and Alloys
  • Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE