329 Environmental effects on crack growth rate for aluminum alloys

Abstract

Sapienza". Pipart; ingbgueria Aerospaziale eAstronautiaa, Via Eudossiana 1& ooIS4 Romeltaly , -Absttact: in the aerospace ocrrnr4unity big conoern is deveteq to the development ofnew materials with high mechanical charapteristics and lcEw density. Many years ago'ocmiposite materials were a blg brornise for '' ''aerospade applications but even tdday'are still far frcmi replacing aluminium alloys. ln this work it wi11 be ' studied "the bchaviour of fatigueoorTosiep of six aluminium alloys. Most of these alloys are ofteq used in ' hofosPade stmctural c(rmponepts,. One of the tested allcys, specifica11y,the 6082, has beeri develeped firr ' 6ffshdre applications such as masts afid struetures used in sailing c(mipetitions. Crack growth rate versus stress intensificaticm factors have been determined at different excitaticm frequencies and at diffu'ent envir6Enmenta1 conditicms fbr all the six all(rys c(nisidered.

Corrosion fatigue characterisation of sintered multiphase stainless steels

“…The tests, repeated three times for each experimental condition, were carried out according to the above mentioned ASTM E-647 standard using an electromagnetic drive testing machine. 10 The specimens were subjected to a sinusoidal stress having a frequency of 5 Hz, maximum and minimum load F max 56000 N and F min 52000 N, thus determining a load ratio R50?3. The test environments were laboratory air and an NaClwater solution.…”

“…Some authors have investigated ways to eliminate the sigma phase from the microstructure by suitable thermal treatments. 7 The aim of this work is to analyse the fatigue and corrosion fatigue resistance (with the same experimental methods used by the authors for other materials [8][9][10] ) of some sintered stainless steels in order to compare their performance with those of the corresponding wrought materials (the fatigue and corrosion fatigue information of which can be found in the literature 11 ), as well as to estimate in a selected mechanical load regime, the influence of a very aggressive environment such as the marine one in which these materials could be successfully used.…”

Use of Fiber Optic Sensors for Monitoring Crack Growth in Fatigue and Corrosion-Fatigue Tests

“…In these last cases we usually refers to corrosion-fatigue. Many studies have been carried out on fatigue and corrosion-fatigue behaviour of metallic materials and test procedure are widely tested and standardized [1][2][3][4]. However new researches actually are conducted employing new test and measure techniques in order to study fatigue phenomena and to better understand the involved mechanisms.…”

“…A previous promising study as been carried out on a composite materials [10]. In this work this strain measuring technique has been applied on an aluminum alloy (2024 T3) previously completely characterized with conventional techniques [2].…”