Formation of Nanocrystalline Structure Upon Severe Thermomechanical Processing and its Effect on the Superplastic Properties of Nickel Base Alloys

2014 ◽  
pp. 739-750
Author(s):  
V.A. Valitov
Keyword(s):  
Thermomechanical Processing ◽  
Nanocrystalline Structure ◽  
Nickel Base ◽  
Superplastic Properties

Influence of Thermo-Mechanical Processing on the Microstructure of Beryllia Dispersed Nickel Alloys

1973 ◽  
Vol 31 ◽  
pp. 184-185
Author(s):  
M.S. Grewal ◽  
S.A. Sastri ◽  
N.J. Grant
Keyword(s):  
High Temperature ◽  
Nickel Alloys ◽  
Thermomechanical Processing ◽  
Cold Work ◽  
High Temperature Strength ◽  
Strengthening Effect ◽  
Mechanical Processing ◽  
Uniform Dispersion ◽  
Oxide Particles ◽  
Nickel Base

Currently there is a great interest in developing nickel base alloys with fine and uniform dispersion of stable oxide particles, for high temperature applications. It is well known that the high temperature strength and stability of an oxide dispersed alloy can be greatly improved by appropriate thermomechanical processing, but the mechanism of this strengthening effect is not well understood. This investigation was undertaken to study the dislocation substructures formed in beryllia dispersed nickel alloys as a function of cold work both with and without intermediate anneals. Two alloys, one Ni-lv/oBeo and other Ni-4.5Mo-30Co-2v/oBeo were investigated. The influence of the substructures produced by Thermo-Mechanical Processing (TMP) on the high temperature creep properties of these alloys was also evaluated.

Plastic Flow and Microstructure Evolution during Thermomechanical Processing of a PM Nickel-Base Superalloy

2013 ◽  
Vol 44 (6) ◽  
pp. 2778-2798 ◽  
Author(s):  
S. L. Semiatin ◽  
K. E. McClary ◽  
A. D. Rollett ◽  
C. G. Roberts ◽  
E. J. Payton ◽  
...  
Keyword(s):  
Plastic Flow ◽  
Microstructure Evolution ◽  
Thermomechanical Processing ◽  
Nickel Base Superalloy ◽  
Nickel Base ◽  
Base Superalloy

Thermomechanical processing of a nickel-base superalloy powder compact

1983 ◽  
Vol 1 (4) ◽  
pp. 201-207 ◽  
Author(s):  
A.Y. Kandeil ◽  
J-P.A. Immarigeon ◽  
W. Wallace ◽  
M.C. de Malherbe
Keyword(s):  
Powder Compact ◽  
Thermomechanical Processing ◽  
Nickel Base Superalloy ◽  
Nickel Base ◽  
Base Superalloy ◽  
Superalloy Powder

Nucleation-Mediated Structural Refinement and Aluminium Alloy Design

2006 ◽  
Vol 519-521 ◽  
pp. 191-196 ◽  
Author(s):  
Barry C. Muddle ◽  
Jian Feng Nie
Keyword(s):  
Amorphous Matrix ◽  
Thermomechanical Processing ◽  
Nanocrystalline Structure ◽  
Al Alloys ◽  
Grain Structure ◽  
Second Phase ◽  
Structural Refinement ◽  
Second Phase Particles ◽  
Solid State Phase Transformation ◽  
Structural Scale

Regardless of whether it is cast microstructure, the grain structure that is the product of thermomechanical processing or the nanoscale dispersions of strengthening second-phase particles, it is inescapable that the structural scale that controls mechanical properties in Al alloys is determined primarily by processes of nucleation during either solidification, recrystallisation or solid-state phase transformation. In those advanced alloys with bulk amorphous or nanocrystalline structure, production of an amorphous precursor is reliant on initial suppression of the nucleation of crystallisation, and subsequent controlled nucleation of dispersed nanocrystals within amorphous matrix. The processes of nucleation that control structural scale in modern Al alloys are briefly reviewed, with a focus on potential for further structural refinement and advances in properties.

Routes to Develop Fine-Grained Magnesium Alloys and Composites for High-Strain Rate Superplasticity

1999 ◽  
Vol 601 ◽  
Author(s):  
Toshiji Mukai ◽  
Hiroyuki Watanabe ◽  
T. G. Nieh ◽  
Kenji Higashi
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
Magnesium Alloys ◽  
High Strain ◽  
Thermomechanical Processing ◽  
Superplastic Forming ◽  
Fine Grained ◽  
Superplastic Properties ◽  
Rapidly Solidified

AbstractSuperplastic properties of magnesium alloys and their composites were reviewed with a special emphasis on the achievement of high strain rate superplastic forming. The role of grain size on superplastic deformation mechanisms was particularly addressed. Commercial Mg-Al-Zn alloys and a ZK60-based composite are used as model materials to illustrate the underlining principles leading to the observation of high strain rate superplasticity. In this paper, experimental results from several processing routes, including thermomechanical processing, severe plastic deformation, and extrusion of machined chips and rapidly solidified powders, are presented. High strain rate superplasticity (HSRS) is demonstrated in ZK60-based composites.

Microstructure and Mechanical Properties of Nanostructured Intermetallic Alloy Based on Ti2AlNb

2008 ◽  
Vol 584-586 ◽  
pp. 153-158
Author(s):  
M.R. Shagiev ◽  
G.A. Salishchev
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Room Temperature ◽  
Thermomechanical Processing ◽  
Nanocrystalline Structure ◽  
Nanostructured Material ◽  
Intermetallic Alloy ◽  
Superplastic Behavior ◽  
Average Grain Size ◽  
Rolling Temperatures

Homogeneous nanocrystalline structure with the average grain size of about 300 nm was produced in Ti2AlNb-based intermetallic alloy by a thermomechanical processing which included multistep isothermal forging at temperatures below the β-transus and intermediate annealings. Nanostructured material possessed excellent mechanical properties. At room temperature, elongations up to 25% were obtained and the ultimate strength reached 1400 MPa. The alloy exhibited superplastic behavior in the temperature range of 850-1000°C. The maximum elongation of 930% and steady state flow stress σ50 of about 125 MPa were obtained at 900°C and strain rate of 4.2×10-3 s-1. The rolling temperatures of nanostructured alloy were defined from analysis of its mechanical behavior at a typical rolling strain rate of about 10-1 s-1 and intermetallic sheets with improved mechanical properties were produced.

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