A. Squillace - Academia.edu (original) (raw)

Papers by A. Squillace

Advanced Materials Research, 2008

Abstract The current research has assessed the correlation between welding parameters and corrosi... more Abstract The current research has assessed the correlation between welding parameters and corrosion behaviour for friction stir welded 6056 aluminium alloy. Different thermal treatments and welding parameters were considered. For the welding parameters studied ...

Key Engineering Materials, 2008

ABSTRACT

Research in Nondestructive Evaluation, 2000

The attention of the present work is focused on the analysis of defects in carbonepoxy laminates.... more The attention of the present work is focused on the analysis of defects in carbonepoxy laminates. Different specimens are manufactured by varying the laminate orientation code, the weave type (preimpregnated or nonimpregnated), and the kind of defect. In particular, defects such as inclusions of spurious materials, delamination, and localized lack or excess of resin are artificially created to simulate the most probable kinds of damage occurring in carbon-epoxy products during manufacturing and/or in service. Nondestructive tests are performed by means of lock-in thermography.

Proceedings of the Institution of Mechanical Engineers, Part L: Journal of Materials: Design and Applications, 2011

ABSTRACT The effect of process parameters on mechanical and microstructural properties of AA 2139... more ABSTRACT The effect of process parameters on mechanical and microstructural properties of AA 2139 T8 joints produced by friction stir welding (FSW) was analysed by means of statistical tools. Three different parameters were taken into account: angular speed (ω), welding speed (v a), and plunging depth (p); each of them was varied on three levels. Forces and temperatures achieved during the welding were monitored and analysed for all joints. An accurate microstructural analysis was performed: the occurrence of some remarkable defects, typical of FSW, such as tunnel or lack of penetration, was related to actual process parameters adopted. The extension of each FSW characteristic zone was measured and the main grain dimension within each of these zones was measured. The mechanical properties of the joints were evaluated by means of Vickers microhardness measurements and tensile tests at room temperature. It was observed that the joint welded with lowest angular speed, highest welding speed, and greatest plunging depth attained the best performances. The statistical data treatment allowed providing a numerical model capable of predicting the mechanical performances of joints.

Journal of Materials Processing Technology, 2006

The effect of processing parameters on mechanical and microstructural properties of AA6056 joints... more The effect of processing parameters on mechanical and microstructural properties of AA6056 joints produced by Friction Stir Welding was analysed in the present study. Different samples obtained by employing rotating speeds of 500, 800 and 1000 rpm and welding speeds of 40, 56 and 80 mm/min were produced. The mechanical properties of the joints were evaluated by means of microhardness (HV) and tensile tests at room temperature. Fatigue tests on the welds were carried out by using a resonant electro-mechanical testing machine under constant loading control up to 250 Hz sine wave loading. The low cycle (LCF) and high cycle (HCF) fatigue tests were conducted in the axial total stress-amplitude control mode with R = σ min /σ max = 0.1, for all the welding and rotating speeds used in the present study. It was observed that the specimens welded at 56 mm/min showed the best behaviour in the low cycle regime. The microstructural evolution of the material was analysed by optical observations of the welds cross sections.

Engineering Failure Analysis, 2009

Al-Li alloys are characterized by a strong anisotropy in mechanical and microstructural propertie... more Al-Li alloys are characterized by a strong anisotropy in mechanical and microstructural properties with respect to the rolling direction. In the present paper sheets, 4 mm thick, of AA2198 Al-Li alloy were joined via Friction Stir Welding (FSW) by employing a rotating speed of 1000 RPM and a welding speed of 80 mm/min, in parallel and orthogonal

This work investigates the influence of the Friction Stir Welding (FSW) parameters on the mechani... more This work investigates the influence of the Friction Stir Welding (FSW) parameters on the mechanical properties AA 2198 T3 welds. For this purpose, a full-factorial experimental design was conducted. The observed responses are ultimate tensile strength (UTS) and yield strength (YS). The factors under investigation are tool rotational speed (N) and welding feed (Va). In order to estimate the influence of the heat transfer transient phase on the mechanical properties of the weld, besides these classical welding parameters, a position parameter defining the relative distance of the specimens from the welding run-in and run-out is considered. Analysis of variance (ANOVA), main effect plot and desirability function technique were used to determine the significant parameters and set the optimal level for each parameter. A regression equation was derived to predict each output characteristic.

ABSTRACT Corrosion fatigue (CF) is defined as the sequential stages of metal damage that evolve w... more ABSTRACT Corrosion fatigue (CF) is defined as the sequential stages of metal damage that evolve with accumulated load cycling, in an aggressive environment, and resulting from the interaction of irreversible cyclic plastic deformation with localized chemical or electrochemical reactions. The pitting fatigue corrosion (PFC) is a part of CF that studies the influence of fatigue and aggressive environment on pit creations and crack generation and propagation, up to catastrophic failure. It appears then evident the need to know and understand all phenomena that are involved in pit formation and growth in presence of both an aggressive environment and a cyclic load. Although each single effect of both fatigue and corrosion have been extensively documented for aluminium alloys, their synergic action is not thoroughly understood and it continues to be an area of considerable scientific and industrial interest. Fatigue experiments were conducted on bare AA 2024 T3 aluminium alloy specimens in presence of an aggressive environment consisting of a water aerated solution with 3.5% of NaCl in weight. The mechanical stress was imposed on simple cantilever beam way in high-cycle fatigue. Strain and Open Circuit Potential (OCP) variations observed as a functions of number of cycles are interpreted as a result, and taking into account, the numerous and complex phenomena occurring as time goes on. The pits birth and their subsequent growth seem to play a significant role as crack initiation and subsequent propagation up to final catastrophic failure.

Composites Part A: Applied Science and Manufacturing, 2002

An experimental investigation was carried out, in order to ®nd simple analytical methods for the ... more An experimental investigation was carried out, in order to ®nd simple analytical methods for the prediction of pin-bearing strength of glass mat reinforced plastics fabricated by hand lay-up.