The influence of testing parameters on stress corrosion crack growth in the high strength aluminium alloy 7010-T651

An interlaboratory testing programme to evaluate the rising displacement test for stress corrosion crack (SCO growth investigations was carried out within the framework of the "Measurements and Testing" programme of the European Community under BCR contract nr. MATI CT 930038. The contribution of the NLR to the project consisted of testing of...

Effects of cooling rate on corrosion properties of high strength aluminium alloys under atmospheric conditions

Long-term outdoor exposure tests were done to investigate the effect of cooling rate on corrosion and stress corrosion properties of extruded rods of the high strength aluminium alloys 2024-T4, 2023-T6, 7075-T6 and 7075-T73. The 2024 alloy exhibited a high susceptibility to SCC irrespective of best treatment and cooling rate, whereas 7075-T6 was...

Spacecraft sustained load fracture control

The opportunities for sustained load fracture control in spacecraft are indicated. Emphasis is given to verification by small-scale laboratory testing.

Long-term outdoor stress corrosion testing of overaged 7000 series aluminium alloys

Long-term outdoor stress corrosion tests were executed on overaged 7000 series aluminium alloy plate and forgings. Plate material of the alloys 7010-T7651, 7010-T7451 and 7075-T7351 exhibited an excellent resistance to SCC. PM alloy X7091-T7E69 forgings combined a higher strength with superior SCC resistance as compared to IM alloy forgings. The...

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...

Effect of cooling rate on corrosion properties and microstructure of high strength aluminium alloys

The Jominy end-quench test was applied to rods of the alximinium alloys T010 and X TO9I to obtain a decreasing cooling rate over the length of the rods. After heat treating to a high strength T6 and an overaged TT condition the corrosion properties and the microstructure were determined related to the cooling rate. No influence of cooling rate...

The use of Arall in fuselage skins

The report starts with a general review of the loading of transport aircraft fuselages and the consequent fuselage skin stresses Taking the F-28 fuselage as an example, the potential weight savings that can be obtained by using ARALL as skin material are assessed. The report ends with conclusions and recommendations

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...

Influence of environments on constant displacement stress corrosion crack growth in high strength aluminium alloys

An experimental investigation was carried out into the applicability of various corrosive environments for stress corrosion crack propagation testing of high strength aluminium alloys using double cantilever beam specimens. Testing under atmospheric conditions was used as a reference. It was found that stress corrosion crack growth under...

Stress corrosion crack initiation testing of high strength aluminium alloys using tuning fork type specimens

An experimental investigation was carried out into the applicability of various corrosive environments for stress corrosion crack initiation testing of high strength aluminium alloys using constant strain loaded tuning fork type specimens. The effect of surface preparation was also involved. The most important findings were that salt-chromate...

The effect of sheet thickness and laminating on the fatigue resistance of the aluminium alloyd AL-7010T73651

The influence of sheet thickness (2 mm and 10 mm) and the influence of laminating (5x2 ram) on the fatigue crack growth properties of the aluminium alloy AL 7010-T 73651 were investigated. Both constant amplitude loading and flight simulation loading were applied. All 2 mm and 10 mm thick sheets were machined from a 150 mm thick plate, i.e....

The Jominy end-quench test for investigation of corrosion properties and microstructure of high strength aluminium alloys

The Jominy end-quench test was applied to extruded rods of the aluminium alloys 2024 and 7075 to obtain a decreasing quench rate over the length of the rods. Subsequently the alloys were heat treated to the conditions: 2024-T4, 2024-T6, 7075-T73. A corrosion investigation and a transmission electron microscopy investigation were performed to...

Comparison of fracture toughness in titanium alloys IMI 550 and IMI 551

Fracture toughness tests on two high strength titanium alloys, IMI 550 and 551, showed that the higher strength alloy, IMI 551, had a much lower toughness. The alloys were very similar in microstructure and fracture mechanisms. A number of model formulations for predicting fracture toughness were compared with the experimental results. This...