Effect of Al alloying on the Hall-Petch strengthening and AE in compressed Mg-Li-Al alloys before and after HPT processing

Pawełek, A.; Ranachowski, Z.; Piątkowski, Andrzej; Kúdela, S.; Ranachowski, P.

doi:10.4149/km_2011_4_271

Cited by 10 publications

(19 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…tendency of AE to decrease reported earlier (Kúdela et al, 2011;Kuśnierz et al, 2008) in the samples of Mg-Li and Mg-Li-Al alloys compressed after processing with intensive deformation, and for comparison, presented here in the section 4.3 of this chapter. The next Figs.…”

mentioning

confidence: 91%

Mechanical Behavior and Plastic Instabilities of Compressed Al Metals and Alloys Investigated with Intensive Strain and Acoustic Emission Methods

Pawełek¹

2011

Recent Trends in Processing and Degradation of Aluminium Alloys

View full text Add to dashboard Cite

mentioning

confidence: 91%

Mechanical Behavior and Plastic Instabilities of Compressed Al Metals and Alloys Investigated with Intensive Strain and Acoustic Emission Methods

Pawełek¹

2011

Recent Trends in Processing and Degradation of Aluminium Alloys

View full text Add to dashboard Cite

“…Series of alloys used in this study were prepared by casting of raw materials in a steel crucible at 800°C with subsequent pouring into a cooled steel mould in a chamber of vacuum induction furnace (Balzers) under low argon pressure (1000 Pa, of 99.999% purity) after previous evacuation (10 -2 Pa). The applied preparation procedure was similar to that reported in [15] and used also in our previous works [5][6][7][8][9]. Then, the alloys were machined into standard specimens with rectangular cross-section.…”

Section: Compression and Tensile Testsmentioning

confidence: 99%

“…The AE method has been applied to the investigations of poly-and single crystals of metals and alloys by the authors of the present paper for many years [5,7,10,17]. The investigations concentrated on explaining the correlations between AE descriptors and the mechanisms of deformation of the materials subjected to the tensile and compression tests.…”

Section: Acoustic Emission Measurementsmentioning

confidence: 99%

“…The measuring system of AE signal was functionally coupled with the stress/strain testing machines and it was described in more details in [5,18]. A broad-band piezoelectric sensor (standard WD type, certified by Physical Acoustics Corporation) enabled to record the acoustic pulses in the frequency range from 100 kHz to 1 MHz.…”

Section: Acoustic Emission Measurementsmentioning

confidence: 99%

“…The occurrence of hot-shortness phenomenon, followed by the fracture of intercrystalline character is an important reason for technological difficulties. Previous investigations of the authors of the paper [5][6][7][8][9] of mechanical properties of alloys with the application of AE method were devoted to the Mg-Li-Al alloys and related composites generally in the context of the method of intensive deformation processes leading to their excellent mechanical properties, such as great strength and plasticity or even superplasticity. On the other hand, the investigations of metal and alloy plastic instability using the AE technique were carried out [10][11][12] mainly in the context of basic aspects of PL effect, twinning or shear band in both poly-and single metal and alloy crystals.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Plastic Instabilities Induced by the Portevin - Le Châtelier Effect and Fracture Character of Deformed Mg-Li Alloys Investigated Using the Acoustic Emission Method

Pawełek

Piątkowski

Wajda

et al. 2016

Archives of Metallurgy and Materials

Self Cite

View full text Add to dashboard Cite

IntroductionUnsatisfying ability to plastic deformation at elevated temperatures, mostly leading to the reduction of deformability and/or hot plasticity is characteristic for many metals and alloys [1][2][3][4]. The occurrence of hot-shortness phenomenon, followed by the fracture of intercrystalline character is an important reason for technological difficulties. Previous investigations of the authors of the paper [5][6][7][8][9] of mechanical properties of alloys with the application of AE method were devoted to the Mg-Li-Al alloys and related composites generally in the context of the method of intensive deformation processes leading to their excellent mechanical properties, such as great strength and plasticity or even superplasticity. On the other hand, the investigations of metal and alloy plastic instability using the AE technique were carried out [10][11][12] mainly in the context of basic aspects of PL effect, twinning or shear band in both poly-and single metal and alloy crystals. The fracture and strengthening properties of Mg-Li based alloys (and composites) were investigated, for example in [13][14][15][16], but without the use of AE method, which proved to be a very useful technique of material examination. In this work the results of the investigations of the correlation between the AE phenomenon, the plastic instability, induced by PL effect, twining or shear bands, and the both, intergranular and transcrystalline fracture of Mg4Li5Al and Mg4Li4Zn alloys subjected to tensile and compression tests at wide range of elevated temperatures are presented.Alloys based on magnesium with lithium, as the lightest ones from among the known metallic construction materials, are very attractive from the point of view of their application as the materials for light, yet durable constructions to be used in the automotive industry (e.g. car engine housings), light housings of computers and aerospace technology. The basic Mg-Li alloys exist in three phase areas. The hexagonal α phase appears in the concentration range of Li up to 4 wt.%. If the content of Li is more than 12 wt.% -the β phase of cubic lattice occurs. The alloys of Li content from 4% up to 12 wt.% form the α+β two-phase mixture. The mechanical properties of α phase are worse from that of the β phase, which is more plastic and thus reveals good machinability and weldability. Alloying additions, e.g. Al (or Zn) from 3% to 5%, slightly increase the density of the alloy, but lead to the precipitation of coherent particles of transition phase, θ-MgLi 2 Al/θ-MgLi 2 Zn, which additionally strengthens the matrix and leads to the improvement of mechanical properties [14]. The present paper addresses the optical microscopic, as well as TEM and SEM observations of the failure of samples after tensile and compression tests.

show abstract

Effect of KOBO Extrusion and Following Cyclic Forging on Grain Refinement of Mg–9Li–2Al–0.5Sc Alloy

et al. 2019

View full text Add to dashboard Cite

KOBO type extrusion and following cyclic forging in two perpendicular directions at temperatures 150-200 °C were applied to new Mg-9Li-2Al-0.5Sc alloy to study its effect on strength and microstructure evolution. KOBO extrusion of as cast ingot caused significant grain refinement of (α + β) dual phase Mg-9Li-2Al-0.5Sc alloys down to range 1-10 μm for hcp α phase and 1-5 μm for the β phase as resulted from EBSD studies. At that stage ultimate tensile strength UTS of 168 MPa and elongation of 36% were attained. Additional deformation by cyclic forging alternatively from 2 perpendicular directions caused formation of much finer grains of average size of few hundred nm observed using TEM and close to 1 μm applying EBSD technique. Tensile strength increased after that operation above 200 MPa and elongation above 40%, which were the highest observed in the dual phase Mg-Li based alloys. Deformation by cyclic forging induced formation of strong texture with 0001 plane parallel to forging directions. Additional precipitates of size below 1 μm at α/β interfaces or within β phase were identified as hcp AlSc 2 phase. Fine particles of hcp α phase were observed after severe plastic deformation SPD within β phase grains, as effect of diffusion assisted deformation. The amount of hcp α phase increased after SPD up to 70% from initial 40%. High density of defects at α/β interfaces on 0001 planes observed in HRTEM mode was responsible for promotion of hcp phase formation during SPD.

show abstract

Effect of Al alloying on the Hall-Petch strengthening and AE in compressed Mg-Li-Al alloys before and after HPT processing

Cited by 10 publications

References 19 publications

Mechanical Behavior and Plastic Instabilities of Compressed Al Metals and Alloys Investigated with Intensive Strain and Acoustic Emission Methods

Mechanical Behavior and Plastic Instabilities of Compressed Al Metals and Alloys Investigated with Intensive Strain and Acoustic Emission Methods

Plastic Instabilities Induced by the Portevin - Le Châtelier Effect and Fracture Character of Deformed Mg-Li Alloys Investigated Using the Acoustic Emission Method

Effect of KOBO Extrusion and Following Cyclic Forging on Grain Refinement of Mg–9Li–2Al–0.5Sc Alloy

Contact Info

Product

Resources

About