Microstructural Change of Beta Type Titanium Alloy by Intense Plastic Deformation

2006 ◽  
Vol 503-504 ◽  
pp. 705-710 ◽  
Author(s):  
Goroh Itoh ◽  
Hisashi Hasegawa ◽  
Tsing Zhou ◽  
Yoshinobu Motohashi ◽  
Mitsuo Niinomi
Keyword(s):  
Plastic Deformation ◽  
Work Hardening ◽  
Static Recrystallization ◽  
True Strain ◽  
Microstructural Change ◽  
Intense Plastic Deformation ◽  
Rolled Plate ◽  
Al Alloy ◽  
Hot Rolled ◽  
Zr Alloy

Usual static recrystallization treatment and a method to provide intense plastic deformation, ARB namely Accumulative Roll-Bonding, have been applied to two beta type titanium alloys, i.e. Ti-29Nb-13Ta-4.6Zr and Ti-15V-3Cr-3Sn-3Al. Microstructural change as well as work-hardening behavior was examined as a function of plastic strain. Both the work-hardening rate and the hardness at the initial as-hot-rolled state were smaller in the Ti-Nb-Ta-Zr alloy than in the Ti-V-Cr-Sn-Al alloy. Recrystallized grains of 14μm in size were obtained by the usual static recrystallization treatment, which was significantly smaller than that of the starting as-hot-rolled plate of 38μm. No significant change other than flattening and elongating of the original grains was found in the optical microscopic scale. It was revealed, however, from a TEM observation combined with selected area diffraction technique that geometric dynamic recrystallization occurred in the Ti-Nb-Ta-Zr alloy deformed at room temperature by a true strain of 5, resulting in an ultra-fine-grained microstructure where the grain size was roughly estimated to be about 100nm.

The Relationship between Mg Content and Extra-Hardening in Ultrafine Grained Al-Mg Alloy by SPD

2018 ◽  
Vol 941 ◽  
pp. 1173-1177
Author(s):  
Yuto Suzuki ◽  
Yuichi Shiono ◽  
Taiki Morishige ◽  
Toshihide Takenaka
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Work Hardening ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Mg Alloy ◽  
Al Alloy ◽  
Ultrafine Grained ◽  
Mg Content ◽  
The Relationship

Severe Plastic Deformation (SPD) process is one of methods for obtaining UFG-Al. It was reported in SPD-processed Al alloy that the extra-hardening due to work hardening caused by accumulated dislocation in the grains. In Al-Mg alloy, Mg decreases the stacking fault energy in this alloy, and dislocation tends to accumulate in the grains. In this study, Al-Mg alloy with various Mg contents were processed by Equal-Channel Angular Pressed (ECAP) which was one of SPD and annealed after processed ECAP. The relationship between Mg content and magnitude of extra-hardening was investigated. In ECAPed Al-3mass%Mg alloy, it was thought that extra-hardening was caused. Magnitude of extra-hardening was increased with increasing Mg content.

Application of High-Strain-Rate Superplastic Zn-Al Alloy to Seismic Dampers and its Optimised Shape Design

2007 ◽  
Vol 551-552 ◽  
pp. 583-590 ◽  
Author(s):  
Atsumichi Kushibe ◽  
Yorinobu Takigawa ◽  
Kenji Higashi ◽  
Kazuo Aoki ◽  
Koichi Makii ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Work Hardening ◽  
Tall Buildings ◽  
High Energy ◽  
Local Deformation ◽  
Al Alloys ◽  
Optimum Shape ◽  
Al Alloy ◽  
Seismic Damper ◽  
Damping Material

As a new damping material, the authors first developed a Zn-22wt.%-Al eutectoid alloy with ultra-fine grains exhibiting superplasticity at room temperature by means of thermomechanical controlling processes (TMCPs). The Zn-Al alloy has a few advantages such as low work-hardening rate and high ductility over a conventional seismic damping material, for instance, a low-yield-point steel. In addition, Zn-Al alloys are environment-conscious because of no harmful metal like Pb. However, when Zn-Al alloys are subjected to plastic deformation, since its work hardening is small, plastic deformation proceeds locally so that required absorption energy cannot be sufficiently obtained, and local fracture and local deformation instability can take place easily, which is the intrinsic characteristic of superplastic materials. Therefore we attempted to develop a shear panel type, a brace type damper for tall buildings and a bending type damper for Japanese wooden houses using FEM analysis in order to minimize localized strain and local deformation and to determine the optimum shape for this Zn-Al superplastic seismic damper. As a result, an ecological and high-energy absorption seismic dampers, so-called “maintenance-free seismic damper,” was successfully developed.

On effect of surface hardening on impact and abrasive wear resistance of Hadfi eld steel

2020 ◽  
pp. 252-255
Author(s):  
V.I. Bolobov ◽  
V.S. Bochkov ◽  
E.V. Akhmerov ◽  
V.A. Plashchinsky ◽  
E.A. Krivokrisenko E.A.
Keyword(s):  
Plastic Deformation ◽  
Wear Resistance ◽  
Abrasive Wear ◽  
Work Hardening ◽  
Surface Hardening ◽  
Cold Work ◽  
Abrasive Wear Resistance ◽  
Hadfield Steel ◽  
Mining Equipment ◽  
Effect Of Surface

On the example of Hadfield steel, as the most common material of fast-wearing parts of mining equipment, the effect of surface hardening by plastic deformation on their impact and abrasive wear resistance is considered. Wear test is conducted on magnetic ironstone as typical representative of abrasive and hard rock. As result of wear of initial samples with hardness of ∼200 HB and samples pre-hardened with different intensities to the hardness of 300, 337 and 368 HB, it is found that during the initial testing period, the initial samples pass the “self-cold-work hardening” stage with increase in hardness to ∼250 HB, which remains virtually unchanged during further tests; the hardness of the pre-hardened samples does not change significantly throughout the tests. It is established that the rate of impact-abrasive wear of pre-hardened samples is significantly (up to 1.4 times) lower than the original ones that are not subjected to plastic deformation, and decreases with increasing degree of cold-work hardening. Preliminary surface hardening by plastic deformation can serve as effective way to increase the service life of fast-wearing working parts of mining equipment.

Deformation Behaviour and Ultrafine Grained Structure Development in Steels with Different Carbon Content Subjected to Severe Plastic Deformation

2007 ◽  
Vol 345-346 ◽  
pp. 45-48 ◽  
Author(s):  
Jozef Zrník ◽  
Sergey V. Dobatkin ◽  
Ondrej Stejskal
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Work Hardening ◽  
Favourable Effect ◽  
Tensile Behaviour ◽  
Dislocation Network ◽  
Strength Increase ◽  
Subgrain Structure ◽  
Low Carbon ◽  
Channel Angle

The article focuses on the results from recent experimental of severe plastic deformation of low carbon (LC) steel and medium carbon (MC) steel performed at increased temperatures. The grain refinement of ferrite respectively ferrite-pearlite structure is described. While LC steel was deformed by ECAP die (ε = 3) with a channel angle φ = 90° the ECAP severe deformation of MC steel was conducted with die channel angle of 120° (ε = 2.6 - 4). The high straining in LC steel resulted in extensively elongated ferrite grains with dense dislocation network and randomly recovered and polygonized structure was observed. The small period of work hardening appeared at tensile deformation. On the other side, the warm ECAP deformation of MC steel in dependence of increased effective strain resulted in more progressive recovery process. In interior of the elongated ferrite grains the subgrain structure prevails with dislocation network. As straining increases the dynamic polygonization and recrystallization became active to form mixture of polygonized subgrain and submicrocrystalline structure. The straining and moderate ECAP temperature caused the cementite lamellae fragmentation and spheroidzation as number of passes increased. The tensile behaviour of the both steels was characterized by strength increase however the absence of strain hardening was found at low carbon steel. The favourable effect of ferrite-pearlite structure modification due straining was reason for extended work hardening period observed at MC steel.

The production of hot-rolled plate steel with reduced tolerances

Metallurgist ◽  
1974 ◽  
Vol 18 (11) ◽  
pp. 853-854
Author(s):  
Yu. V. Konovalov ◽  
L. B. Gorskii ◽  
A. E. Rudnev ◽  
V. P. Samoilov ◽  
G. I. Manshilin ◽  
...  
Keyword(s):  
Rolled Plate ◽  
Plate Steel ◽  
Hot Rolled

Ferromagnetism caused by severe plastic deformation of the Fe – 35% Al alloy

2011 ◽  
Vol 53 (12) ◽  
pp. 1325-1330
Author(s):  
Ya. A. Abzgildin ◽  
R. F. Al’mukhametov ◽  
N. G. Zaripov ◽  
H. Ya. Mulyukov
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
Al Alloy
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