Crack resistance, fracture toughness and instability in damage tolerant Al-Li alloys

A comparison is made of the crack resistance (R-curve), fracture toughness and instability behaviour of candidate damage tolerant aluminiumlithium alloys, 2091 and 8090, and the widely used conventional 2024-T3 alloy. The 2091 alloy was in three heat treatment conditions, T8X, TX and TY, all artificially aged. The 8090 alloy was in the T81...

Damage tolerance and durability evaluation of aluminium-lithium alloys

New impetus to continued use of alximinium alloys in major structural areas of aircraft has been given by the development of aluminium-lithium alloys. However, qualification of these new materials for service requires extensive testing and evaluation, preferably in international cooperative programmes. The evaluation of aluminium-lithium alloys...

Engineering property comparisons for 2324-T39 and 2024-T351 aluminium alloy plate

Engineering property comparisons have been made for plate material of the newly developed aluminium alloy 2324-T39 and the widely used alloy 2024-T351. The properties considered were: tensile strength, fracture toughness, notched fatigue strength, and the resistance to fatigue crack propagation under both constant amplitude and flight simulation...

Fracture toughness and corrosion properties of the aluminium plate alloys 7010-T651 and 7150-T6E189

A comparative experimental investigation was done on the advanced plate alloys 7010-T651 from ALCAN and 7150-T6E189 from ALCOA. The mechanical properties, fracture toughness and corrosion properties were determined. The most notable finding was the excellent fracture toughness of alloy 7150-T6E189 combined with a high tensile strength. The...

Engineering property comparisons of PM alloy X7091-T7E69 and IM alloy forgings

The engineering properties of PM alloy X7091-T7E69 forgings were compared with those of forgings of the IM alloys 7075-T73, 7175-T736, 7050-T736 and 7010-T736. The properties considered were: strength, fracture toughness, fatigue crack propagation under constant amplitude and flight simulation loading, stress corrosion crack initiation and...

Engineering property comparisons of the aluminium plate alloys 7050-T7365I, 7010-T7365I and 7010-T765I

The Al-Zn-Mg-Cu alloy 7050 produced by Alcoa is a typical plate and forging alloy because of its low quench sensitivity. In order to compare this alloy with the earlier tested plate alloy 7010 an experimental programme was performed involving tensile, fracture toughness, and fatigue testing. In addition stress corrosion crack initiation and...

Engineering properties of the recently developed aluminium alloy designated 7010

An experimental investigation.was performed on 80 mm thick plate material of 7OIO-T7651 and 7OIO-T73651 developed by Alcan Industries Ltd in U.K. The testing programme involved: tensile tests, fracture toughness, stress corrosion and fatigue tests. For comparison a similar investigation vas carried out on 7075-T7351 Alcoa plate material.

Residual strength properties of carbon/epoxy composite material

Fatigue tests on unidirectional Ca/ep composite material have been performed to investigate whether previous fatigue loading did influence the residual static strength. Residual strength tests were carried out on (0, ± 45)2s and (± 45)2s laminates, while for the (O, ± 45)2s laminate the influence of previous tensile fatigue loading on the...

Residual strength of the aluminium alloy 7475-T76 at low temperatures

Residual strength tests have heen performed, on 300 mm wide centrecracked panels of various thicknesses, at room temperature and at -50 C. During the tests, stable crack growth was filmed and recorded with the electric potential method. Fracture toughness was determined using the method of Feddersen.

Scanning electron microscopy of fracture surfaces of carton composite materials

A microscopic study has been performed on carbon composite fracture surfaces, using the Scanning Electron Microscope (SEM). It appears that the SEM is a useful tool to examine the fracture surface characteristics of composite materials failing under different loading conditions.

Fracture toughness and fatigue properties of the new aluminium alloy 7475-T76

Residual strength tests have been performed on 610 mm wide centre cracked panels. During the tests, stable crack growth was filmed and crack opening displacements were measured. Fracture toughness was determined using the method of Feddersen. Flight simulation fatigue tests were carried out to investigate the crack propagation properties. A...