Nanostructure Formation and Properties in Some Al Alloys after SPD and Heat Treatment

Kvačkaj, Tibor; Bidulská, Jana; Fujda, Martin; Kočiško, Róbert; Pokorný, Imrich; Milkovič, Ondrej

doi:10.4028/www.scientific.net/msf.633-634.273

Cited by 15 publications

(14 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is * corresponding author; e-mail: tibor.kvackaj@tuke.sk unique and it indeed represents interesting cases from the point of view of mechanical properties [58]. In recent years, the scientic research has been focused on the increase of strength in Al alloys by SPD methods without any ageing treatment [9].…”

mentioning

confidence: 99%

Mechanical and Structural Properties of High Purity Al Processed by ECAP

et al. 2012

View full text Add to dashboard Cite

The mechanical properties and substructure formation of high purity aluminium (99.999%) processed by severe plastic deformation method (equal channel angular pressing) were studied. The equal channel angular pressing process was carried out at room temperature by route C (sample rotation around the axis about 180• after each pass) in a die with two channels intersecting at an angle of Φ = 90. The softening mechanism through dynamic recovery was recognized up to 6th equal channel angular pressing pass, however, after that the mechanical strengthening was revealed. The samples after equal channel angular pressing processing were annealed in dierent temperature and time conditions. The inuence of annealing temperature and time on microhardness as well as diameter of grain size were investigated in samples processed by the 4th equal channel angular pressing pass.

show abstract

mentioning

confidence: 99%

Mechanical and Structural Properties of High Purity Al Processed by ECAP

et al. 2012

View full text Add to dashboard Cite

show abstract

“…The heat treaded state of composite generally showed a remarkable increase in the 0.2% yield strength and ultimate tensile strength (about 242 % and 165 %, respectively). This behaviour was related to strengthening mechanism of precipitation of β´´-Mg 2 Si phase particles in 6061 aluminum matrix, that occurred during aging treatment of AlMgSi alloys [27]. Strengthening effect produced by precipitation of β´´-Mg 2 Si phase particles is accompanied by losses in ductility and impact resistance of this type of alloy [20].…”

Section: Discussionmentioning

confidence: 99%

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF EXTRUDED SiC/6061 COMPOSITE

Glogovský¹,

Fujda²,

Vojtko³

et al. 2015

Acta Metall Slovaca

Self Cite

View full text Add to dashboard Cite

The effect of heat treatment on microstructure and mechanical properties of extruded SiC/6061 aluminium alloy matrix composite was investigated. The heat treatment (annealing at 540 °C for 1.5 hours, water quenching and artificial aging at 170 °C for 7 hours) caused dissolution of Mg 2 Si particles and decomposition of small SiC particles. The 0.2 % yield strength and the ultimate tensile strength of extruded composite were increased by application of heat treatment due to precipitation of β´´ phase particles. On the other hand, the ductility of composite was decreased. The fracture surface of as-extruded composite was consisted of numerous dimples. It was a result of micro voids nucleation at interface between matrix and SiC particles and secondphase particles. The fracture of heat treated composite was similar, micro voids were nucleated mainly on SiC particles, which were cracked during tensile test.

show abstract

“…Thus, by taking measurements along linear traverses it is possible to obtain quantitative information on the variations of hardness and homogeneity on selected planes of sectioning after ECAP. In the last decades several studies focused on the mechanical behavior and the microstructural evolution of pure Al and Al alloys processed by ECAP [6][7][8][9][10][11][12][13][14][15]. However, very little information is available at present on the evolution of microhardness and on degree of homogeneity existing along the orthogonal and longitudinal axes of billets processed by ECAP [17,18], although this information is important if the pressed billets will be used in industrial application.…”

Section: Introductionmentioning

confidence: 99%

“…The present research was undertaken with the objective to use microhardness measurements to evaluate the level of homogeneity within the pressed sample of AA 3004, processed by ECAP. Earlier investigations, conducted on samples processed by either ECAP [10][11][12][13][14][15] or high-pressure torsion (HPT) [21], demonstrated a direct correlation between microhardness measurements and the average grain sizes determined using transmission electron microscopy. Accordingly, it is reasonable to anticipate that a homogeneity in the hardness measurements will correspond also to a reasonable homogeneity in the internal microstructure.…”

Section: Introductionmentioning

confidence: 99%

MICRO-HARDNESS EVOLUTION OF Al-ALLOY AA 3004, PROCESSED BY EQUAL CHANNEL ANGULAR PRESSING

Izairi¹,

Ajredini²,

Ristova³

et al. 2013

Acta Metall Slovaca

View full text Add to dashboard Cite

Equal Channel Angular Pressing (ECAP) is a very interesting method for modifying the microstructure in producing materials with ultrafine grain in sub-micrometer or nanometre range. Experiments demonstrate that these ultrafine structures may exhibit, by comparison with large -grained polycrystals, major differences in some fundamental properties. A nanostructured AA 3004 alloy was used to investigate the evolution of microhardness and microstructure on the cross-sectional plane X, after processing by ECAP at room temperature for up to six passes. The measurements show the average microhardness increases significantly after two passes with additional increases in subsequent passes. Microhardness values increase by more than two times after 6 passes. There is a reduction in grain size from of ~ 50µm in the initial condition to ~ 12 µm after 6 passes. The results also show that the microstructure and the microhardness evolve with increasing strain so that, after a total of 6 passes, the structure is almost homogenous throughout the cross-sectional plane of the billet.Keywords: Al alloy; SPD; ECAP; micro-hardness; homogeneity IntroductionExtensive studies of equal-channel angular pressing (ECAP) and other severe severe plastic deformation (SPD) techniques, over the past two decades [1][2][3] have established the processing techniques and have shown the possibility of producing ultrafine grain (UFG) structure in many metals and alloys. Grain size reduction is one of the most attractive ways of improving the mechanical properties of metallic materials. It is known that the strength of all polycrystalline materials is related to the grain size, through the Hall-Petch equation which predict an increase in yield strength (σ y ) with a decrease in grain size (d): σ y = σ 0 + kd -1/2 [4,5]. Several different SPD procedures are now available but the most popular appears to be Equal Channel Angular Pressing (ECAP), that was first proposed in the 80 s, by Segal. In processing by ECAP the sample is pressed through a die containing two channels equal in cross-section, intersecting at an angle φ that is generally close to 90 o (Fig. 1). Since the sample emerges from

show abstract

Nanostructure Formation and Properties in Some Al Alloys after SPD and Heat Treatment

Cited by 15 publications

References 15 publications

Mechanical and Structural Properties of High Purity Al Processed by ECAP

Mechanical and Structural Properties of High Purity Al Processed by ECAP

EFFECT OF HEAT TREATMENT ON MICROSTRUCTURE AND MECHANICAL PROPERTIES OF EXTRUDED SiC/6061 COMPOSITE

MICRO-HARDNESS EVOLUTION OF Al-ALLOY AA 3004, PROCESSED BY EQUAL CHANNEL ANGULAR PRESSING

Contact Info

Product

Resources

About