scholarly journals Transformations of the Microstructure and Phase Compositions of Titanium Alloys during Ultrasonic Impact Treatment. Part I. Commercially Pure Titanium

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 562
Author(s):  
Alexey Panin ◽  
Andrey Dmitriev ◽  
Anton Nikonov ◽  
Marina Kazachenok ◽  
Olga Perevalova ◽  
...  
Keyword(s):  
Surface Layer ◽  
Phase Transformations ◽  
Pure Titanium ◽  
Surface Plastic ◽  
Commercially Pure Titanium ◽  
Ultrasonic Impact Treatment ◽  
Coordination Numbers ◽  
Microscopy Technique ◽  
Transmission Electron ◽  
Treated Sample

Experimental and theoretical studies helped to reveal patterns of surface roughening and the microstructure refinement in the surface layer of commercial pure titanium during ultrasonic impact treatment. Applying transmission electron microscopy technique, a gradient microstructure in the surface layer of the ultrasonically treated sample, where the grain size is varied from nano- to micrometers was revealed. It was shown that the surface plastic strains of the titanium sample proceeded according to the plastic ploughing mechanism, which was accompanied by dislocation sliding, twinning, and the transformations of the microstructure and phase composition. The molecular dynamics method was applied to demonstrate the mechanism of the phase transformations associated with the formation of stacking faults, as well as the reversible displacement of atoms from their sites in the hcp lattice, causing a change in coordination numbers. The role of the electronic subsystem in the development of the strain-induced phase transformations during ultrasonic impact treatment was discussed.

High Energy Shot Peening of Commercially Pure Titanium TIG Weld Joint

2010 ◽  
Vol 148-149 ◽  
pp. 659-663
Author(s):  
Chun Huan Chen ◽  
Rui Ming Ren
Keyword(s):  
Surface Layer ◽  
Weld Joint ◽  
Shot Peening ◽  
Welded Joint ◽  
Pure Titanium ◽  
High Energy ◽  
Commercially Pure Titanium ◽  
Nanostructured Surface ◽  
Commercially Pure ◽  
Cp Ti

Commercially pure Titanium (CP-Ti) TIG weld joint was treated by means of high energy shot peening (HESP) using a shot peening equipment commonly used in industry. The nanostructured surface layer was characterized by XRD, TEM, SEM and Microhardometer. The results showed that surface nanocrystallization of CP-Ti TIG weld joint were realized by high energy shot peening treatment. The finest grain size in the top surface layer is about 40nm. The hardness of the surface layer is enhanced significantly after shot peening compared with that of the as-welded joint, which resulted in a remarkable surface hardening effect. Surface welded defects such as air pores are eliminated successfully so that relative uniform surface layer was obtained.

Wear Assessment of Ti/SiC Surface Nano-Composite Layer and its Associated CP-Ti Substrate

2012 ◽  
Vol 445 ◽  
pp. 595-600 ◽  
Author(s):  
Ali Shamsipur ◽  
Seyed Farshid Kashani-Bozorg ◽  
Abbas Zarei Hanzaki
Keyword(s):  
Surface Layer ◽  
Wear Behavior ◽  
Composite Layer ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Micro Hardness ◽  
Wear Properties ◽  
Friction Stir ◽  
Pin On Disc ◽  
Cp Ti

In the present investigation, the surface of a commercially pure titanium (CP-Ti) substrate was modified to Ti/SiC nanocomposite layer employing friction stir processing technique; nanosized SiC powder was introduced into the stir zone provided by a rotating and advancing tool. The fabricated nanocomposite surface layer exhibited a micro hardness value of ~535HV which is much greater than 160HV of the substrate material using Vickers micro hardness testing. In addition, the un-treated CP-Ti substrate showed sever wear regime in the pin-on-disc test against the hardened AISI 52100 steel. It suffers extensive typical adhesive wear dominated by plastic deformation as evidenced by scanning electron microscopy. Also, deep grooves were formed, i.e. evidence of abrasive wear. Contrary to this, enhanced wear properties were detected for the Ti/SiC nanocomposite surface layer, i.e. lower coefficient of friction and weight loss. The nanocomposite surface layer was found to be adherent to the underlying substrate during the pin-on-disc test. The superior wear behavior of the nanocomposite surface layer is attributed to its improved micro hardness value due to the presence of hard nanosize SiC particles in a refined titanium matrix.

The Effect of Strain Rate on the Plastic Deformation Mode of CP-Ti during Surface Nanocrystallization

2011 ◽  
Vol 675-677 ◽  
pp. 239-242
Author(s):  
Chun Huan Chen ◽  
Cheng Jin ◽  
Rui Ming Ren
Keyword(s):  
Plastic Deformation ◽  
Surface Layer ◽  
Strain Rate ◽  
Shot Peening ◽  
Pure Titanium ◽  
Deformation Mode ◽  
Rate Variation ◽  
Commercially Pure Titanium ◽  
Surface Nanocrystallization ◽  
Cp Ti

The effect of the strain rate on the surface nanocrystallization of titanium is investigated both theoretically and experimentally in this paper. The strain rate variation and stress distribution from surface to the interior of titanium during shot peening are estimated firstly using finite element method. Then shot peening experiment is carried out on a commercially pure titanium (CP-Ti) plate, and the obtained surface microstructures is characterized by transmission electron microscopy (TEM). Combining theoretical simulations and experimental observations, the effect of strain rate on the strain accommodation mechanism and plastic deformation mode are discussed. It is concluded that the strain rate and stress achieve the highest at the top surface layer of CP-Ti, and the strain rate decrease dramatically from the surface to the interior. The strain rate at the top surface layer is up to 104 s-1, which leads to superplastic deformation of Ti. There is no mechanical twin in the surface layer, instead, deformation lamella and adiabatic shear bands are the dominating microstructures. By means of rotation recrystallization, those deformation bands evolve to nanocrystallines.

Strain localization of commercially pure titanium subjected to ultrasonic impact treatment followed by uniaxial tension

2016 ◽  
Author(s):  
Alexey Panin ◽  
Marina Kazachenok ◽  
Anna Kozelskaya ◽  
Olga Perevalova ◽  
Ruslan Balokhonov ◽  
...  
Keyword(s):  
Uniaxial Tension ◽  
Strain Localization ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Ultrasonic Impact Treatment ◽  
Commercially Pure

scholarly journals Исследование влияния обработки лазерными импульсами наносекундной длительности на микроструктуру и сопротивление усталости технически чистого титана

2022 ◽  
Vol 48 (2) ◽  
pp. 15
Author(s):  
Ю.Р. Колобов ◽  
С.С. Манохин ◽  
В.И. Бетехтин ◽  
А.Г. Кадомцев ◽  
М.В. Нарыкова ◽  
...  
Keyword(s):  
Subsurface Layer ◽  
Pure Titanium ◽  
Laser Pulses ◽  
Fatigue Tests ◽  
Nanosecond Laser ◽  
Commercially Pure Titanium ◽  
Transmission Electron ◽  
Effect Of Treatment ◽  
Recrystallized Grain Size ◽  
Titanium Grade

The effect of treatment with nanosecond laser pulses on the fatigue resistance of plate samples of recrystallized (grain size of the order of 2-3 µm) commercially pure titanium (grade VT1-0) under cyclic tensile loading is studied. The results of investigations by methods of scanning and transmission electron microscopy of the microstructure of the subsurface layer of the alloy under study after exposure to nanosecond laser irradiation and subsequent fatigue tests are presented.

Nanostructured Surface Layers In Low Carbon Steel and Pure Titanium Induced By High-Speed Rotating Wire-Wheel Deformation

2010 ◽  
Vol 97-101 ◽  
pp. 1352-1355
Author(s):  
Xin Min Fan ◽  
Fei Yan Liu ◽  
Jie Wen Huang
Keyword(s):  
Surface Layer ◽  
Carbon Steel ◽  
High Speed ◽  
Pure Titanium ◽  
Low Carbon Steel ◽  
Coarse Grained ◽  
Commercially Pure Titanium ◽  
Low Carbon ◽  
Cross Sectional ◽  
Average Grain Size

A nanostructure surface layer was produced on low carbon steel and commercially pure titanium using high-speed rotating wire-wheel deformation (HRWD). The microstructural features of the surface layer were systematically characterized by cross-sectional optical microcopy observations, transmission electron microscopy, and microhadness measurement was conducted along the depth from top surface layer to matrix of the samples. The results show that nearly equiaxed nanocrystalline layer is formed on the surface of the low carbon steel and pure titanium, in which the average grain size is about 8 nm and 15 nm respectively. The microhardness of the top surface is enhanced obviously compared with that of the coarse-grained matrix.

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