Damage tolerance property comparisons for 2000 and 8000 series aluminium plate alloys

This report compares the mechanical properties, fracture toughness and fatigue crack growth properties of the damage tolerant/medium strength aluminium plate alloys 2024-T351, 2324-T39, 8090-T651 and 8090-T8171. The main objective, in view of previous work, was to determine whether damage tolerant 8090-T8171 plate can advantageously replace the...

Modern aluminium sheet alloys for aerospace applications

Fracture toughness and crack resistance of damage tolerant and high strength Al-Li alloys

Flight simulation and constant amplitude fatigue crack growth in aluminium-lithium sheet and plate

Since 1984 the NLR has done many fatigue crack growth tests to compare the modern Al-Li alloys 2090, 2091 and 8090 with the conventional damage tolerant alloys 2024 and 2324. Under constant amplitude loading the Al-Li alloy crack growth behaviour is often equivalent or superior to that of the conventional alloys. However, under gust spectrxim...

Fatigue crack growth in Al-Li sheet alloys in the in-service inspectable damage tolerance regime

The fatigue crack growth properties of several aluminium-lithium (Al-Li) sheet alloys were compared with those of the widely used conventional 2024-T3 alloy. The data, which are relevant to the in-service inspectable damage tolerance regime, were obtained using constant amplitude and flight simulation (gust spectrum) loading. The Al-Li alloys...

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...

Fracture and fatigue evaluation of damage tolerant Al-Li alloys for aerospace applications

Qualification of Al-Li alloys for damage tolerant aerospace structures requires extensive testing and evaluation. In this paper the emphasis is on fracture and fatigue crack growth properties of two candidate sheet alloys, 2091 and 8090, compared with the conventional and widely used 2024 alloy. The relative merits of these materials are...

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...

Patch repair of corroded aircraft skin areas

Environmental conditions in Europe are conducive to corrosion attack of aircraft structures. In military aircraft corrosion problems occur especially at countersunk fastener holes. The corrosion is generally removed by grinding. A limited amount of material removal is specified by the aircraft manufacturers, but it is sometimes necessary to...

Advanced aluminium alloy plate materials for damage tolerant aircraft structures

Engineering properties of the recently developed plate alloy 2324-T39 and the conventional alloy 2024-T351 are compared. Some results for the aluminium-lithium alloy DTD XXXA-T651 (Aluminium Association designation 8090) are also included. The strengths of 2324-T39 and DTD XXXA-T651 were comparable and significantly higher than that of 2024-T351...

Flight simulation fatigue crack propagation in 7010 and 7075 aluminium alloy plate

The fatigue crack propagation resistances of 7010-T7651, 7010-T73651 and 7075-T7351 thick plate were compared for flight simulation (gust spectrum) loading conditions. 7075-T7351 was slightly superior, and it was shown that this superiority was not essentially due to the higher fracture toughness of this alloy. The influence of specimen...