scholarly journals The influence of surface roughness and high pressure torsion on the growth of anodic titania nanotubes on pure titanium

2016 ◽  
Vol 387 ◽  
pp. 1010-1020 ◽  
Author(s):  
Nan Hu ◽  
Nong Gao ◽  
Marco J. Starink
Keyword(s):  
Surface Roughness ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Pure Titanium ◽  
Titania Nanotubes

scholarly journals Slippage during high-pressure torsion of commercially pure titanium and application of accumulative HPT to it

2022 ◽  
Vol 1213 (1) ◽  
pp. 012003
Author(s):  
D V Gunderov ◽  
A A Churakova ◽  
A V Sharafutdinov ◽  
V D Sitdikov ◽  
V V Astanin
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Pure Titanium ◽  
Phase Changes ◽  
Phase Content ◽  
Commercially Pure Titanium ◽  
Micro Hardness ◽  
Ω Phase ◽  
Commercially Pure ◽  
First Time

Abstract A new efficient method was used to find that in the case of high-pressure torsion of commercially pure titanium, accumulation of shear strain in Ti does not occur due to slippage of anvils. Despite this, micro-hardness increases as the number of turns n increases, and Ti structure is refined more intensively. High-pressure torsion is accompanied by a high-pressure ω-phase formation. However, the content of ω-phase changes non-monotonously with an increase in the number of turns. First, while number of turns is less than n=5, the ω-phase content reaches 50%. Upon further deformation, the ω-phase content decreases to 15% for n=20. A new accumulative high-pressure torsion method is applied to commercially pure titanium for the first time. Accumulative high-pressure torsion leads to the strongest transformation of the structure and an increase in hardness, since stronger real deformation occurs due to composition of compression and torsion strain cycles.

Effect of grain size on the micro-tribological behavior of pure titanium processed by high-pressure torsion

Wear ◽  
2012 ◽  
Vol 280-281 ◽  
pp. 28-35 ◽  
Author(s):  
Chuan Ting Wang ◽  
Nong Gao ◽  
Mark G. Gee ◽  
Robert J.K. Wood ◽  
Terence G. Langdon
Keyword(s):  
Grain Size ◽  
High Pressure ◽  
High Pressure Torsion ◽  
Tribological Behavior ◽  
Pure Titanium

Microstructure and metallic ion release of pure titanium and Ti–13Nb–13Zr alloy processed by high pressure torsion

2016 ◽  
Vol 91 ◽  
pp. 340-347 ◽  
Author(s):  
Ivana Dimić ◽  
Ivana Cvijović-Alagić ◽  
Bernhard Völker ◽  
Anton Hohenwarter ◽  
Reinhard Pippan ◽  
...  
Keyword(s):  
High Pressure ◽  
High Pressure Torsion ◽  
Pure Titanium ◽  
Ion Release ◽  
13Zr Alloy

scholarly journals High Pressure Torsion of Pure Ti: Effect of Pressure and Strain on Allotropy

2010 ◽  
Vol 89-91 ◽  
pp. 171-176 ◽  
Author(s):  
Kaveh Edalati ◽  
Z. Horita ◽  
Masaki Tanaka ◽  
Kenji Higashida
Keyword(s):  
High Pressure ◽  
Phase Formation ◽  
Bending Strength ◽  
High Pressure Torsion ◽  
Applied Pressure ◽  
Pure Titanium ◽  
Equivalent Strain ◽  
Bending Tests ◽  
Commercial Grade ◽  
Wide Range

High-pressure torsion (HPT) was conducted on commercial grade pure titanium (99.4%) by applying pressures in a wide range from 1.2 to 40 GPa. When the microhardness was plotted against equivalent strain, the hardness saturates to a constant level at each applied pressure. Such a level at the saturation depends on the applied pressure: for up to the pressure of 4 GPa, the saturation level is independent of the pressure but, for the pressures above 4 GPa, the hardness gradually increases with pressure because of the formation of an  phase. Bending tests showed that an excellent ductility as well as high bending strength was achieved for the sample processed at 2 GPa. The bending ductility was reduced for the sample at 6 GPa because of the  phase formation.

scholarly journals Microstructural Evolution and Microhardness Variations in Pure Titanium Processed by High‐Pressure Torsion

2020 ◽  
Vol 22 (6) ◽  
pp. 1901462 ◽  
Author(s):  
Wanji Chen ◽  
Jie Xu ◽  
Detong Liu ◽  
Jianxing Bao ◽  
Shima Sabbaghianrad ◽  
...  
Keyword(s):  
High Pressure ◽  
Microstructural Evolution ◽  
High Pressure Torsion ◽  
Pure Titanium

scholarly journals Investigating Anvil Alignment and Anvil Roughness on Flow Pattern Development in High-Pressure Torsion

2016 ◽  
Vol 1818 ◽  
Author(s):  
Yi Huang ◽  
Megumi Kawasaki ◽  
Terence G. Langdon
Keyword(s):  
Surface Roughness ◽  
High Pressure ◽  
Stainless Steel ◽  
High Pressure Torsion ◽  
Flow Patterns ◽  
Processing Technique ◽  
Model Material ◽  
Two Phase ◽  
Designed Experiments ◽  
Pattern Development

ABSTRACTHigh-pressure torsion (HPT) is a processing technique in which samples are subjected to a high pressure and torsional straining. Anvil alignment and anvil roughness are two important factors related to the successful application of the HPT processing technique. Using a two-phase duplex stainless steel as a model material, experiments were conducted by placing the anvils in different amounts of initial misalignment. Experiments show that the flow patterns (the development of double-swirl patterns) in HPT are dependent upon the alignment of the anvils within the HPT facility. Through carefully designed experiments, it is shown that the presence of a double-swirl is a feature of HPT processing when the initial positions of the anvils have a small lateral misalignment. The effect of the double-swirl patterns on the hardness evolution was also evaluated quantitatively. By comparing the flow patterns developed on the disc upper surface using both rough and smooth anvils with a fixed anvil misalignment, it was demonstrated that there are some differences in the flow patterns which are dependent upon the anvil surface roughness.

scholarly journals Structural and Mechanical Properties of Ti–Co Alloys Treated by High Pressure Torsion

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 426 ◽  
Author(s):  
Boris Straumal ◽  
Anna Korneva ◽  
Askar Kilmametov ◽  
Lidia Lityńska-Dobrzyńska ◽  
Alena Gornakova ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Annealing Temperature ◽  
High Pressure Torsion ◽  
Pure Titanium ◽  
Eutectoid Transformation ◽  
Ω Phase ◽  
Preliminary Annealing ◽  
Increasing Temperature ◽  
Co Alloys

The microstructure and properties of titanium-based alloys can be tailored using severe plastic deformation. The structure and microhardness of Ti–4 wt.% Co alloy have been studied after preliminary annealing and following high pressure torsion (HPT). The Ti–4 wt.% Co alloy has been annealed at 400, 500, and 600 °C, i.e., below the temperature of eutectoid transformation in the Ti–4 wt.% Co system. The amount of Co dissolved in α-Ti increased with increasing annealing temperature. HPT led to the transformation of α-Ti in ω-Ti. After HPT, the amount of ω-phase in the sample annealed at 400 °C was about 80­85%, i.e., higher than in pure titanium (about 40%). However, with increasing temperature of pre-annealing, the portion of ω-phase decreased (60–65% at 500 °C and about 5% at 600 °C). The microhardness of all investigated samples increased with increasing temperature of pre-annealing.

An Investigation of Hardness Homogeneity and Microstructure in Pure Titanium Processed by High Pressure Torsion

2014 ◽  
Vol 783-786 ◽  
pp. 2701-2706 ◽  
Author(s):  
Chuan Ting Wang ◽  
Alan G. Fox ◽  
Terence G. Langdon
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Grain Size ◽  
High Pressure ◽  
Dislocation Density ◽  
Vickers Microhardness ◽  
High Pressure Torsion ◽  
Pure Titanium ◽  
Commercial Purity ◽  
Transmission Electron

High-pressure torsion (HPT) was conducted on disks of commercial purity Ti under applied pressures of 3 and 6 GPa. Measurements of the Vickers microhardness showed improving hardness homogeneity with increasing numbers of HPT turns. Transmission electron microscopy demonstrated that a higher HPT pressure leads to a smaller grain size after straining and these grains contain a high dislocation density with arrays of twins. This is consistent with the higher hardness of the Ti samples processed by HPT under 6 GPa pressure.

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