In situ observation of microcrack growth in 8090-T[sub 4] alloy

Journal Article · Wed Sep 01 04:00:00 EDT 1993 · Scripta Metallurgica et Materialia; (United States)

OSTI ID:6273096

Yun, Zhang; Yongbo, Xu; Yulin, Liu; Suhua, Ai; Hongen, Zhao; Zhangqi, Hu ^[1]

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1. Academia Sinica, Shenyang (China). Inst. of Metal Research

Aluminum-lithium alloys have become of recent interest as potentially important aerospace structural materials because of their low density, high elastic modulus and strength. However, some Al-Li alloys show very low tensile ductility and fracture toughness, particularly at peak-aged conditions. Vasudevan and Starke et al. recognized that Al-Li alloys were highly sensitive to intergranular fracture. Noble emphasized the effect of strain localization at coarse slip bands. Although much research has been published, the problem still has not been satisfactorily resolved. In contrast, the 8090-T[sub 4] alloy exhibits good comprehensive properties. In this paper, in situ observations in a TEM were carried out in the 8090-T[sub 4] alloy in order to study the deformation characteristics near the crack tip as well as microcrack growth. The results can be used to define the microstructure/property relationship in Al-Li alloys. Some results on fracture mechanisms at peak-and over-aged conditions will be reported later, so that the relationship between fracture mechanism, tensile ductility and the resistance to crack growth can be elucidated.

• OSTI ID: 6273096
• Journal Information: Scripta Metallurgica et Materialia; (United States), Journal Name: Scripta Metallurgica et Materialia; (United States) Vol. 29:5; ISSN SCRMEX; ISSN 0956-716X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360103* -- Metals & Alloys-- Mechanical Properties
AEROSPACE INDUSTRY
ALLOYS
ALUMINIUM ALLOYS
CRACK PROPAGATION
DATA
DENSITY
DUCTILITY
ELASTICITY
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
FRACTURE PROPERTIES
INDUSTRY
INFORMATION
LITHIUM ALLOYS
MECHANICAL PROPERTIES
MICROSCOPY
NUMERICAL DATA
PHYSICAL PROPERTIES
TENSILE PROPERTIES
TRANSMISSION ELECTRON MICROSCOPY