151 research outputs found
Dynamic recrystallization and production of ultrafine-grain structure in magnesium alloys
No full textPurpose: development of materials microstructure control method within a wide range of grain sizes. The work determines the action of various mechanisms of the dynamic recrystallization in magnesium alloys and shows the effect of the initial structure and microstructure on the dynamic recrystallization. The author proposes the conditions for obtaining a preset structure and a process of production of high-strength blanks from alloy MA21. The process of strengthening and stabilizing the properties of alloy MA21 is adopted for use in the Mechanical Engineering Design Office of the city of Miass. The results of the work are recommended for use at enterprises of the aerospace industryAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio
Effect of normalizing and tempering on structure and mechanical properties of advanced martensitic 10% Cr–3% Co–0.2% Re steel
No full text
Effect of ECAP on Microstructure and Mechanical Properties of an Al-Mg-Sc Alloy
No full textAn Al-4.57%Mg–0.2%Sc was subjected to equal channel angular pressing up to fixed true strains of 1, 2, 4, 8 and 12 at a temperature of 300oC. It was shown that extensive grain refinement occurs in this alloy through continuous dynamic recrystallization. As a result, ECAP can provide the formation of subgrain structure, partially recrystallized structure and fully recrystallized structure. The type of structure evolved is dependent on strain imposed. At ε2, the formation of three-dimensional arrays of low-angle boundaries takes place. Next, in the strain interval from 4 to 8 these low-angle boundaries gradually convert into high-angle boundaries. At ε12, fully recrystallized structure is evolved. Yield stress and ultimate strength gradually increases with increasing strain. Mechanisms of strengthening are discussed.</jats:p
DYNAMIC RECRYSTALLIZATION, MECHANISMS OF PLASTIC DEFORMATION IN MAGNESIUM ALLOYS AND IN STEELS
No full textThere the systematic study of structural changes during the plastic flow and during the deformation mechanism of magnesium alloys, of steels of diverse classes as well as of YBa*002Cu*003O*007 ceramic compound and LiF ion crystal has been realized in view to the determination of physics of dynamic recrystallization processes. The experimental data have been compared with the design results from the diverse theoretical simulators. It was ascertained that phenomenology, the kinetics and the mechanisms of dynamic recrystallization are determined by the existing mechanisms of plastic deformation. The formation mechanisms of recrystallized grains have been offered on the basis of obtained results. The special notice have been taken for the consideration of structure evolution in the cold deformation process with the superhigh degreesAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio
Grain refinement and strengthening of a Cu–0.1Cr–0.06Zr alloy subjected to equal channel angular pressing
No full textMicrostructure Evolution in an Al-Cu-Mg-Ag Alloy during ECAP at 300°C
No full textA novel Al-Cu-Mg-Ag alloy with small additions of zirconium and scandium was subjected to equal channel angular pressing (ECAP) by using route BC at 300°C to strains ranging from ~1 to ~12. Initially, the alloy was subjected to solution treatment followed by water quenching; subsequent overageing was carried out at 380°C for 3 h. It was shown that continuous dynamic recrystallization (CDRX) occurs during ECAP resulting in partially recrystallized structure; at a total strain of ~12, the portion of high-angle boundaries (HAB) attains 50 pct., average misorientation is ~25°. Crystallites having elongated shape and an average size of ~1 μm are evolved after a total strain of ~12.</jats:p
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