Temperature effect on fine-grained structure formation in high-strength Al alloy 7475 during hot severe deformation

2009 ◽  
Vol 516 (1-2) ◽  
pp. 180-188 ◽  
Author(s):  
O. Sitdikov ◽  
T. Sakai ◽  
H. Miura ◽  
C. Hama
Keyword(s):  
Temperature Effect ◽  
Structure Formation ◽  
High Strength ◽  
Al Alloy ◽  
Fine Grained ◽  
Severe Deformation ◽  
Fine Grained Structure

Influence of Physical Properties of B4C Powder on the Strength Properties of the Ceramics Manufactured by SPS Sintering

2015 ◽  
Vol 1085 ◽  
pp. 312-315
Author(s):  
Oleg L. Khasanov ◽  
Edgar S. Dvilis ◽  
Zulfa G. Bikbaeva ◽  
Valentina V. Polisadova ◽  
Alexey O. Khasanov ◽  
...  
Keyword(s):  
Physical Properties ◽  
Boron Carbide ◽  
Physical And Mechanical Properties ◽  
High Strength ◽  
Strength Properties ◽  
Carbide Powder ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
Determining Factor ◽  
Sps Sintering

Ceramics samples in the form of a parallelepiped with high strength characteristics have been made. For the manufacture of the ceramics samples a powder mixture from submicron В4С powder with additives (1 wt%, 5 wt%, 10 wt%) of boron carbide nanopowder was used. The physical properties of the powder mixtures and strength properties of sintered ceramics have been studied. It was shown that the use of submicron fractions of the boron carbide powder together with nanoadditives is a determining factor in the formation of dense fine-grained structure providing improved physical and mechanical properties of the ceramics.

Fine-Grained Structure Formation in Al- Mg- Sc Alloy during Hot ECAP

2006 ◽  
Vol 503-504 ◽  
pp. 721-726 ◽  
Author(s):  
Oleg Sitdikov ◽  
Rustam Kaibyshev ◽  
Elena Avtokratova ◽  
Kaneaki Tsuzaki
Keyword(s):  
Structure Formation ◽  
Fine Grained ◽  
Fine Grained Structure

Influence of ECAP Routes on the Microstructure and Mechanical Properties of Hot Extruded 3003 Al Alloy

2007 ◽  
Vol 124-126 ◽  
pp. 1397-1400 ◽  
Author(s):  
Byoung Soo Lee ◽  
Hoon Cho
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Hot Extrusion ◽  
High Strength ◽  
Al Alloy ◽  
Deformation Structure ◽  
Ecap Processing ◽  
Fine Grained ◽  
Strain Process ◽  
Equiaxed Grains

The microstructures and mechanical properties of unidirectional deformation structured Al alloy during ECAP with various deformation routes were investigated. In order to fabricate unidirectional deformation structure for Al alloy, hot extrusion was carried out. It was found that the deformation route A in ECAP routes is the dominant route for the grain refinement and strengthening. In deformation route A, the high strength ultra-fine grained Al alloy with a grain size of ~ 200 nm was obtained due to the accumulation of consecutive strain process. In contrast, the strength of ECAP’ed Al alloy produced via deformation route C was greatly increased after one pass because the grains were strained and cancelled each pass. By contrast, the equiaxed grains were obtained in deformation route BC because the sample was rotated 90 O in the same sense in each pass. The deformation route BC was superior to the deformation route C because the deformation route BC was more favorable than the deformation route C in the accumulation of consecutive strain. It is also found that unidirectional deformation structured Al alloy via hot extrusion shows similar grain refinement tendency with equiaxed structured Al alloy during ECAP processing.

The Influence of Addition of the Rare Earth Elements on the Structure and Hardness of AlZn12Mg3.5Cu2.5 Alloy

2015 ◽  
Vol 226 ◽  
pp. 39-42
Author(s):  
Rafał Michalik ◽  
Tomasz Mikuszewski
Keyword(s):  
Rare Earth ◽  
Automotive Industry ◽  
Electrical Power ◽  
High Strength ◽  
Hardness Test ◽  
Relative Strength ◽  
Zinc Alloys ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
High Strength Aluminum Alloys

Aluminium alloys are characterized by a number of advantageous properties , which include: low density ,high relative strength , high electrical and thermal conductivity , ease of machining and good dumping features. Particular interesting are high-strength aluminum alloys of zinc, magnesium and copper. These alloys are used mainly in aircraft, building &structure, electrical, electrical power and automotive industry. A significant problem associated with the use of high-strength aluminium-zinc alloys is their insufficient resistance to corrosion. Improvement of corrosion resistance can be obtained by application of alloy micro-additives. The article shows results of examinations related to influence of rare earth additive on the structure and hardness of AlZn12Mg3.5Cu2.5 alloy. The scope of examination included: structure testing using scanning microscope, X – ray microanalysis, hardness test. Examinations have shown higher hardness of samples with rare earth additives. Was found , that rare earth addition influences on more fine –grained structure of the AlZn12Mg3.5Cu2.5 alloy.

Development of Ultra-Fine Grained Structure in an Al-5.4%Mg-0.5%Mn Alloy Processed by ECAP

2010 ◽  
Vol 667-669 ◽  
pp. 487-492
Author(s):  
Alla Kipelova ◽  
Ilya Nikulin ◽  
Sergey Malopheyev ◽  
Rustam Kaibyshev
Keyword(s):  
Plastic Deformation ◽  
Structure Formation ◽  
Equal Channel Angular Pressing ◽  
Microstructural Evolution ◽  
Coarse Grained ◽  
High Angle ◽  
Fine Grained ◽  
Angular Pressing ◽  
Fine Grained Structure ◽  
Zr Alloy

Microstructural changes during equal channel angular pressing (ECAP) at the temperatures of 250 and 300°C to the strains ~4, ~8 and ~12 were studied in a coarse-grained Al-5.4%Mg-0.5%Mn-0.1%Zr alloy. At a strain of ~4, the microstructural evolution is mainly characterized by the development of well-defined subgrains within interiors of initial grains and the formation of fine grains along original boundaries. Further straining leads to increase in the average misorientation angle, the fraction of high-angle grain boundaries and the fraction of new grains. However, only at 300°C, the plastic deformation to a strain of ~12 leads to the formation of almost uniform submicrocrystalline (SMC) grained structure with an average crystallites size of ~ 0.5 m. At 250°C, the microstructure remains non-uniform and consists of subgrains and new recrystallized grains. The mechanism of new SMC structure formation after ECAP is discussed.

Effect of pressing temperature on fine-grained structure formation in 7475 aluminum alloy during ECAP

2004 ◽  
Vol 381 (1-2) ◽  
pp. 121-128 ◽  
Author(s):  
A Goloborodko ◽  
O Sitdikov ◽  
R Kaibyshev ◽  
H Miura ◽  
T Sakai
Keyword(s):  
Aluminum Alloy ◽  
Structure Formation ◽  
Pressing Temperature ◽  
Fine Grained ◽  
Fine Grained Structure

Grain Refinement of 6061 Al Alloy by the Modified Strain-Induced Melt- Activated(SIMA) Process for Semi-Solid Processing

2007 ◽  
Vol 119 ◽  
pp. 311-314 ◽  
Author(s):  
Young Buem Song ◽  
Chun Pyo Hong
Keyword(s):  
Grain Refinement ◽  
Grain Structure ◽  
Al Alloy ◽  
Fine Grained ◽  
Fine Grain ◽  
Fine Grained Structure ◽  
Size Uniformity ◽  
Sima Process ◽  
Semi Solid ◽  
6061 Al Alloy

The dynamic process of fine grain evolution of 6061 aluminum alloy during modified strain-induced, melt-activated (SIMA) process was studied. The modified SIMA process employed casting, two stage homogenization, warm multi-forging, and recrystallization and partial melting (RAP). Multi-forging was carried out at a strain rate of 9x10-3 s-1 to accumulate high strains, with decreasing temperature from 250 to 200 °C. The alloy multi-forged with the accumulated strain of about 12 and RAP at 640 °C for 10 min exhibited the uniform equiaxed recrystallized grain structure. Accordingly, it was evident that multi-forging was very effective on grain refinement and grain size uniformity. The present modified SIMA process was discussed as an alternative thermo-mechanical processing for preparing the alloys with fine grained structure for semi solid processing.

STRUCTURAL PROPERTIES AND ABRASIVE- WEAR RESISTANCE OF BRINAR 400 AND BRINAR 500 STEELS

Tribologia ◽  
2017 ◽  
Vol 273 (3) ◽  
pp. 67-75 ◽  
Author(s):  
Łukasz KONAT ◽  
Jerzy NAPIÓRKOWSKI ◽  
Beata BIAŁOBRZESKA
Keyword(s):  
Wear Resistance ◽  
Abrasive Wear ◽  
Sandy Loam ◽  
High Strength ◽  
Abrasive Wear Resistance ◽  
Martensitic Steels ◽  
Fine Grained ◽  
Carbide Phases ◽  
Fine Grained Structure ◽  
Steel Grades

In the paper, microstructures and the examination results of abrasive-wear resistance of steel grades Brinar 400 and Brinar 500 are presented. It was found on the grounds of light and electron scanning microscopy that these steels are characterised by subtle differences in microstructures, influencing their mechanical and usable properties. In as-delivered condition, the steels have fine-grained structure with post-martensitic orientation, containing few particles of carbide phases. Such microstructures of Brinar steels and the performed chemical analyses indicate that their properties are formed during specialised operations of thermo-mechanical rolling. Generally, it can be said that the examined steels were designed according to the accepted standards of material engineering, related to low-alloy, high-strength, and abrasive-wear resistant martensitic steels. According to the above, the obtained results of structural examinations of Brinar 400 and Brinar 500 steels were referred to real abrasive-wear indices obtained by the spinning bowl method with use of various abrasive soil masses. The tests carried-out in light soil (loamy sand), medium soil (sandy loam), and in heavy soil (loam), as well as hardness measurements showed strict dependence of abrasive-wear indices on microstructures and the heattreatment condition of the examined steels. Examination results of abrasive-wear resistance of Brinar steels were compared with those of steel 38GSA in normalised conditions.

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