Formation of a nanocrystalline structure upon severe thermomechanical treatment and its effect on the superplastic properties of a nickel alloy with nonisomorphic second-phase precipitates

2006 ◽  
Vol 102 (1) ◽  
pp. 97-104 ◽  
Author(s):  
V. A. Valitov ◽  
Sh. Kh. Mukhtarov ◽  
Yu. A. Raskulova
Keyword(s):  
Nickel Alloy ◽  
Thermomechanical Treatment ◽  
Nanocrystalline Structure ◽  
Second Phase ◽  
Superplastic Properties

A Comparative Study of Structure Formation in Thermomechanically Treated Ti-Ni and Ti-Nb-(Zr, Ta) SMA

2012 ◽  
Vol 706-709 ◽  
pp. 1931-1936 ◽  
Author(s):  
Sergey Prokoshkin ◽  
Vladimir Brailovski ◽  
Karine Inaekyan ◽  
Andrey Korotitskiy ◽  
Sergey Dubinskiy ◽  
...  
Keyword(s):  
Cold Rolling ◽  
Comparative Study ◽  
Shape Memory Alloys ◽  
Shape Memory ◽  
Structure Formation ◽  
Thermomechanical Treatment ◽  
Functional Properties ◽  
Nanocrystalline Structure ◽  
Technological Factors

The processes of structure formation in Ti-Ni and in Ti-Nb-Zr, Ti-Nb-Ta shape memory alloys (SMA) under thermomechanical treatment (TMT) were studied. The TMT comprised cold rolling with true strains from e=0.25 to 2 and post-deformation annealing. Differences in these processes between two groups of alloys are considered. The main conclusions are as follows: nanostructures created by TMT are useful for radical improvement of the SMA functional properties, and an optimum nanostructure (nanocrystalline structure, nanosubgrained structure or theirmixture) should be selected by taking into account other structural and technological factors.

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.

Effects of Thermomechanical Treatment Process on the Microstructure and Properties of 7A04 Aluminum Alloy

2011 ◽  
Vol 335-336 ◽  
pp. 805-808 ◽  
Author(s):  
Shi Xing Zhang ◽  
Hai Hong Wu ◽  
Gang Yi Cai
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Thermomechanical Treatment ◽  
Ageing Time ◽  
Solution Treatment ◽  
Second Phase ◽  
Microstructure And Properties ◽  
Treatment Processes ◽  
Phase Precipitate ◽  
Peak Value

The mechanical properties of a 7A04 aluminum alloy were improved by deformation strengthening and phase transformations strengthening adopting thermomechanical treatment, whose process include solution treatment, deformation treatment and ageing treatment in turn. The paper focuses on the influences of deforming degree and ageing process on microstructure and properties of 7A04 aluminum alloy. The experimental results show that hardness increased with increasing deformation ratio, and the value are greatly higher than that of samples after solution treatment. The results of ageing after deformation show that the hardness enhanced with prolonging the ageing time, which reach the peak value at 16 hours. In addition, the microstructure became more homogeneous and the grain was refined obviously by metallography microscope observation. The second phase precipitate dispersedly to strengthen the alloy. Above all, in order to obtain the better mechanical properties, the optimal thermomechanical treatment processes are solution treatment at 470°C for 2h, deformation with ratio of 40% as well as ageing at 120°C for 16h.

Effects of Thermomechanical Treatment Process on the Microstructure and Properties of Al-Zn-Mg Alloy

2011 ◽  
Vol 239-242 ◽  
pp. 847-850
Author(s):  
Gang Yi Cai ◽  
Yu Yong Yang ◽  
Xiao Hua Li
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Thermomechanical Treatment ◽  
Ageing Time ◽  
Solution Treatment ◽  
Second Phase ◽  
Microstructure And Properties ◽  
Treatment Processes ◽  
Phase Precipitate ◽  
Peak Value

The mechanical properties of Al-Zn-Mg aluminum alloy were improved by deformation strengthening and transformations strengthening adopting thermomechanical treatment, whose process are solution treatment, preageing treatment, deformation treatment and ageing treatment in turn. The paper focuses on the influences of deforming degree and ageing process on microstructure and properties of Al-Zn-Mg aluminum alloy. The experimental results show that hardness increased with increasing deformation ratio, and the value are greatly higher than that of samples after solution treatment. The results of ageing after deformation show that the hardness enhanced with prolonging the ageing time, which reach the peak value at 16 hours. In addition, the microstructure became more homogeneous and the grain was refined obviously by metallography microscope observation. The second phase precipitate dispersedly to strengthen the alloy. Above all, in order to obtain the better mechanical properties, the optimal thermomechanical treatment processes are solution treatment at 470°C for 2h, preageing treatment at 140°C for 24h, deformation with ratio of 40% as well as ageing at 120°C for 16h.

Formation of the nanocrystalline structure in the Ti50Ni25Cu25 shape-memory alloy under severe thermomechanical treatment

2011 ◽  
Vol 112 (6) ◽  
pp. 603-612 ◽  
Author(s):  
V. G. Pushin ◽  
N. N. Kuranova ◽  
A. V. Pushin ◽  
N. I. Kourov ◽  
V. P. Pilyugin
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Thermomechanical Treatment ◽  
Nanocrystalline Structure
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