Experimental ballistic performance of friction stir processed aluminum (AA6061-B 4 C) surface composite

Magarajan

Proceedings of the Institution of Mechanical Engineers, Part L:

2022

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In this paper, an attempt was made to study the ballistic resistance of Friction Stir Welded (FSW) AZ31B magnesium alloy. The base metal AZ31B plates were sliced to required size and FSW was carried out using a non-consumable taper pin tool made up of HCHCr steel. Samples were taken out from the FSW plates to study the microstructure and microhardness. The FSW AZ31B contain refined grains and tiny Mg17Al12 precipitates which were formed because of severe plastic deformation during FSW. The FSW AZ31B targets also showed ∼7.47% increase in microhardness compared to BM target. Further, ballistic test was conducted by impacting Ø7.62 × 39 mm hard steel core projectiles at an initial velocity of 420 m/s. AA6062 material of 25 mm was used as backing plate to measure the Depth of Penetration (DOP) of the projectile. The failure mechanism and the ballistic resistance of BM and FSW AZ31B samples were studied and compared. Finally, post ballistic analysis was made to study the failure modes of the target at microscopic level. Through various experimental results, it was identified that the increase in ballistic resistance of FSW AZ31B target was mainly due to two reasons; the refinement of grain size and small strengthening precipitates.

Section: Resultsmentioning

confidence: 99%

Investigation on ballistic behaviour of friction stir welded rolled AZ31B magnesium alloy

Magarajan

Proceedings of the Institution of Mechanical Engineers, Part L:

2022

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“…The reduction of DOP value was attributed due to higher hardness and presence of Mg 17 Al 12 precipitate particles. Magarajan et al [43,44] also reported that the ballistic resistance of the target significantly increased because of higher hardness value. The SCT targets of SZ and HAZ have higher ballistic resistance compare to FSW targets, but it was lower than that of DCT targets.…”

Section: Ballistic Performances In Terms Of Dopmentioning

confidence: 96%

Influence of Post Weld Cryogenic Treatment on the Ballistic Penetration Resistance of Friction Stir-Welded AZ31B Magnesium Alloy

Proceedings of the Institution of Mechanical Engineers, Part C:

2022

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Influence of post weld cryogenic treatment conditions (deep and shallow) on the ballistic resistance of friction stir welded (FSW) AZ31B magnesium alloy has been investigated. AZ31B welded joints which were prepared by using friction stir welding process were subjected to two types of cryogenic treatment conditions. The microstructural investigation of cryogenic treated joints showed the formation of Mg17Al12 precipitates and conversion of coarse eutectic phase into thin discontinues phase along with halos. In addition, superior microhardness values were noticed for the cryogenically treated joints compared with non-treated joints and base metal. High velocity ballistic experiments were conducted on cryogenically treated and non-treated weld targets using 7.62 mm deformable projectiles at an initial velocity of 450 ± 10 m/s. At the stir zone, the depth of penetration (DOP) of the projectile into the deep cryogenic treated (DCT) target was observed to be 11% and 34 % lesser than the shallow cryogenic treated (SCT) and FSW targets. Thus increase in the ballistic resistance was observed for the post-weld cryogenic treated FSW joints compared to non-treated FSW joints. SEM investigation of the projectile impacted DCT targets showed the formation of cracks, dimples and micro voids at the crater region. It is also noticed that, the Stir Zone (SZ) and Heat Affected Zones (HAZ) of the DCT target has effectively absorbed the ballistic impact energy of the projectile by a ductile fracture and hence DCT can be used to improve the ballistic penetration resistance of the FSW joints at the SZ and HAZ regions.

“…Over all, from the literature, it was noticed that FSW and FSP are the better manufacturing processes for fabricating defence structural parts. Yu et al [ 19 ] created a “thermo-mechanical model” for the FSW process using the ABAQUS environment. Iqbal et al [ 20 ] assessed the “ballistic performance” of “monolithic”, and “multi-layered mild steel targets” using “ABAQUS software”.…”

Section: Introductionmentioning

confidence: 99%

Comparative analysis of experimental and numerical investigation on multiple projectile impact of AA5083 friction stir welded targets

Balaji¹,

Kumar²,

Magarajan³

et al. 2023

PLoS ONE

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This research aims to investigate the ballistic resistance of base material (BM)and “Friction Stir Welded (FSW)”, AA5083 aluminum alloy. The primary objective was to build a finite element model to predict kinetic energy absorption and target deformation under single and multiple projectile impact conditions. This study employed 7.62mm Hard Steel Core (HSC) projectiles produced from Steel 4340. The target was analyzed using commercially available Abaqus Explicit software for Finite Element Analysis. It was noticed that the generation of kinetic energy and surface residual velocity increases as the number of projectile strikes increases. In addition, the experimental ballistic test was conducted to validate the numerical results. Using the analytical Recht-Ipson model, each target’s experimental residual velocity was determined. It was determined that weldments perform less well (30%) as compared to BM targets. Occurrence of plastic deformation during welding causes reduction in ballistic performance of weldments. For both the computational and experimental approaches, a correlation between residual velocities was found. The plastic deformations with ductile hole formation were observed in all the cases.