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...

Fractographic examination of specimens from lEPG TA 31 creep tests

The NLR examined by fractography nine ruptured creep specimens supplied by EGT. Three specimens had been tested at 600° C and six specimens had been tested at 650° C. Internal (creep) cracking occured by transgranular microvoid coalescence, which is likely to be characteristic for standard heat treatment Inconel 718. One specimen tested at 600°...

Fatigue and fracture of aerospace aluminium alloys: a short course

This report contains the overhead sheets of a short course on fatigue and fracture of aerospace aluminium alloys, plus an annex in the form of a review paper.

Corrosion fatigue crack arrest in aluminium alloys: basic data

Constant amplitude low stress Intensity fatigue crack growth for 2024-T3 and 7475-T761 aluminium alloys In laboratory air, sump tank water and synthetic seawater was Investigated. Corrosion fatigue crack grouwt retardation and arrest occurred In both sump tank water and synthetic seawater, resulting In higher AKth values than In air. Crack...

Fracture characteristics of carbon and aramid unidirectional composites in interlaminar shear and open hole tensile tests.

This investigation examined carbon/epoxy and aramide/epoxy composites in interlaminar shear and in open-hole tensile tests at 90 to the unidirectional fibre orientation. Epoxy resin was also tested under tension. Photomicroscopy and the S.E.M. were used to study the fracture surfaces. Wet tests were performed to investigate the influence of...

Effect of penetrant on fatigue of aluminium alloy lap joints

The effect of penetrant on the fatigue life of single shear riveted lap joints was investigated by flight simulation fatigue tests using the MINITWIST gust spectrum. The penetrant/material combination investigated was ARDROX 985 P3T and aluminium alloy 202U-T3 sheet material (both bare and clad) respectively. The effect of penetrant on the...

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...

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 influence of different types of anodic layers on the fatigue properties of 202U-T3 and 7056-T6 sheet material

Constant amplitude and flight simulation fatigue tests have been carried out on sulphuric acid, chromic acid and phosphoric acid anodized specimens. A comparison was made with the fatigue behaviour of bare sheet material. Before fatigue testing the fracture strain of the anodic layers was determined.

The reclanation of improperly cadmium electroplated high strength steel parts

Circumferentially notched round specimens of 4340 type steel have been plated in a galvanic bath known to be embrittling. The specimens were reclaimed by stripping and baking. Half the specimens were replated in a non-embrittling bath. Reclamation did not remove all traces of hydrogen embrittlement, but raised the threshold stress to such a...

Environmental fatigue crack propagation in Ti-6A1-4V sheet: Revised Edition

A study was made of environmental fatigue crack propagation in 2.5 mm thick Ti-6A1-4V sheet conforming to AMS 4911, and 2.2 mm thick IMI 3l8 conforming to BS TA 10. The environments were dry argon, normal air, distilled water and 3.5 ^ aqueous NaCl. There were three alloy/orientation combinations: Ti-6A1-4V L-T, IMI 3l8 L-T and IMI 318 T-L. Test...