On the PLC Effect in a Particle Reinforced AA2017 Alloy

Härtel, M.; Illgen, Christian; Frint, Philipp; Wagner, Martin F.‐X.

doi:10.3390/met8020088

Cited by 32 publications

(18 citation statements)

References 56 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This serration-flow behaviour is called the Portevin-Le Chatelier (PLC) effect during the plastic deformation of the material [28]. The substitute and interstitial alloys, such as Al alloys [42], carbon steel [43], and copper alloys [44], tend to demonstrate PLC behaviour during tensile loading [45]. The PLC effect is related to pinning and unpinning processes, where the pinned process has occurred when the dislocation is stuck by obstacles formed from the forest dislocations and grain boundaries.…”

Section: Tensile Propertiesmentioning

confidence: 99%

“…The frequencies of serration are different because of the stress fields of the grain size, in which the serration frequency is high for the as-welded sample. After rolling, the serration causes the stress to increase with increased rolling percentage because of the pinning effect [42]. Thus, the strain hardening increasing during rolling results in decreasing crystallite size and lattice strain for the sample.…”

Section: Tensile Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Cold-Rolling Strain Hardening Effect on the Microstructure, Serration-Flow Behaviour and Dislocation Density of Friction Stir Welded AA5083

Sajuri

Selamat

Baghdadi

et al. 2020

Metals

View full text Add to dashboard Cite

5083 aluminium (Al) alloy materials have extensive structural applications in transportation industries because of their high strength-to-weight ratio and corrosion resistance. However, under conventional fusion weldings, these materials are limited by their porosity, hot cracking, and distortion. Herein, friction stir welding (FSW) was performed to join a similar AA5083 alloy. A post-weld cold-rolling (PWCR) process was applied on joint samples at different thickness-reduction percentages (i.e., 10%, 20%, and 40%) to identify the effect of strain hardening on the microstructure and mechanical properties of the friction-stir-welded joint of AA5083 while considering the serration-flow behaviour at stress–strain curves and dislocation density of the post-weld cold-rolled (PWCRed) samples. FSW induced a 20% reduction in the tensile strength of the joint samples relative to the base metal. PWCR also reduced the average grain size at the nugget zone and base metal because of the increase in plastic deformation imposed on the samples. Furthermore, PWCR increased the dislocation density because of the interaction among dislocation stress fields. Consequently, the tensile strength of the friction-stir-welded joint increased with the increased cold-rolling percentage and peaked at 403 MPa for PWCRed–40%, which significantly improved the serration-flow behaviour of stress–strain and welding efficiency up to 123%.

show abstract

Section: Tensile Propertiesmentioning

confidence: 99%

Section: Tensile Propertiesmentioning

confidence: 99%

Cold-Rolling Strain Hardening Effect on the Microstructure, Serration-Flow Behaviour and Dislocation Density of Friction Stir Welded AA5083

Sajuri

Selamat

Baghdadi

et al. 2020

Metals

View full text Add to dashboard Cite

show abstract

“…They observed characteristic oscillations on strain-stress curves in aluminum-based alloys and low-carbon steels [1]. Since then, the Portevin-Le Chatelier effect (PLC) has been extensively studied in copper and aluminum-based alloys during tensile or compression tests [2][3][4][5]. However, in the case of steels the PLC effect was studied rarely [5][6][7].…”

Section: Introductionmentioning

confidence: 99%

Explanation of the PLC Effect in Advanced High-Strength Medium-Mn Steels. A Review

et al. 2019

View full text Add to dashboard Cite

The paper reviews the recent works concerning the Portevin-Le Chatelier (PLC) effect in Advanced High-Strength Steels (AHSSs) with a special attention to high-strength medium-manganese steels. Theories explaining the mechanism of the plastic instability phenomenon in steels with medium-and high-Mn contents were discussed. The relationships between microstructural effects such as TRIP (Transformation-Induced Plasticity), TWIP (Twinning-Induced Plasticity) and the PLC effect were characterized. The effects of processing conditions including a deformation state (hot-rolled and cold-rolled) and strain parameters (deformation temperature, strain rate) were addressed. Factors affecting the value of critical strain for the activation of serrated flow behavior in particular in medium-manganese steels were described.The explanation of the Portevin-Le Chatelier mechanism in medium-Mn steels showing the TRIP effect is a complicated issue because of their microstructure consisting of several phases, as well as the TRIP effect exhibited by these steels. The exact characteristics of the factors affecting the PLC effect in AHSS is very important, both from a research point of view and their industrial implementation. This overview concerns the PLC phenomenon in Advanced High Strength Steels (AHSSs), with particular emphasis on advanced medium-Mn TRIP steels. The Nature of PLC Effect in SteelsThe plastic instability phenomenon occurring during the deformation of metallic materials shows two most common forms of propagative bands: Lüders and Portevin-Le Chatelier bands. The Lüders bands refer to the regions of localized strain. They form immediately after the onset of plastic deformation from the yield point drop, followed to a dominant stage of the stress plateau stage. Lüders bands are commonly caused by static strain aging (SSA) [13]. Static strain aging is characterized by an increase in strength properties associated with a decrease in plasticity. The PLC bands are represented by characteristic serrations on stress-strain curves. PLC bands are usually related to the dynamic strain aging (DSA) effect. The occurrence of the PLC bands is much more erratic, and can be observed in various forms (serration types) in comparison to the Lüders bands.There are several theories which explain the PLC effect in metallic materials. However, none has been so far clearly confirmed. The first interpretation of this phenomenon was proposed by Cottrell [1]. From his point of view, the PLC effect is related to the interactions between solute atoms, such as C or N, and mobile dislocations. The presence of serrations on a tensile curve is associated with the rapid release of dislocations from the atmospheres of dissolved atoms, which block their movement. This model is based on the assumption that atmospheres are formed around dislocations due to volume diffusion. In the presence of substitution atoms, diffusion is facilitated by vacancies resulting from plastic deformation. The interstitial gaps located in the vicinity of the dislocation are enl...

show abstract

“…Clarke and Hinton [2] pointed out that these oscillations may be misinterpreted as special material characteristics. However, several researchers have observed and concluded that the serration phenomenon is actually a material property and it depends on the material type, strain rate and temperature [7,[10][11][12]15,21,26,27]. Nevertheless, the effect of auto-tuning on the serration behavior has not been reported so far.…”

Section: The Effect Of Auto-tuningmentioning

confidence: 99%

“…The plastic deformation in metals and alloys is mainly attributed to the nucleation and motion of dislocations [20]. The PLC effect has been investigated by stress and strain-controlled tensile tests as well as digital image correlation and acoustic emission [21]. Recently some researchers have reported the PLC effect under compressive loading as well [9].…”

Section: Introductionmentioning

confidence: 99%

Effect of Auto-Tuning on Serrated Flow Behavior

Mohammed

Chen

2019

Metals

View full text Add to dashboard Cite

The mechanical response of a servo-hydraulic testing system is affected by the stiffness of test specimens. An adaptive controller helps in auto-tuning the system by setting the optimal proportional-integral-derivative values for the subsequent test as the stiffness changes. This paper presents the effect of auto-tuning of various channels on the flow response of several commercial Al and Mg alloys and a mild steel. Strain-controlled monotonic tensile tests were performed at a given strain rate of 1 × 10−4 s−1 after auto-tuning of position, load, and strain channels in different combinations. Serrated flow or Portevin–Le Chatelier effect was observed in the Al alloys after auto-tuning of either position channel only or position and load channels. However, the serrations of Al alloys were shielded after further auto-tuning of strain channel. The stress-strain curves of Mg alloys and mild steel were observed to be basically free of serrations under any combinations of auto-tuning, which confirms that the serrated flow is a property of specific materials rather than a machine system noise.

show abstract

On the PLC Effect in a Particle Reinforced AA2017 Alloy

Cited by 32 publications

References 56 publications

Cold-Rolling Strain Hardening Effect on the Microstructure, Serration-Flow Behaviour and Dislocation Density of Friction Stir Welded AA5083

Cold-Rolling Strain Hardening Effect on the Microstructure, Serration-Flow Behaviour and Dislocation Density of Friction Stir Welded AA5083

Explanation of the PLC Effect in Advanced High-Strength Medium-Mn Steels. A Review

Effect of Auto-Tuning on Serrated Flow Behavior

Contact Info

Product

Resources

About