Structure and electrochemical behaviour of weldments of titanium Grade 1 in a bromine-containing solution

2021 ◽  
Vol 112 (1) ◽  
pp. 5-12
Author(s):  
M.D. Ilieva ◽  
N.V. Ferdinandov ◽  
D.D. Gospodinov ◽  
R.H. Radev
Keyword(s):  
Hollow Cathode ◽  
Heat Affected Zone ◽  
Corrosion Behaviour ◽  
Arc Discharge ◽  
Pure Titanium ◽  
Passive Layer ◽  
Commercially Pure Titanium ◽  
Protective Properties ◽  
Titanium Grade ◽  
Cathode Arc

Purpose: The presented research aims to determine the microstructural changes in weldments of commercially pure titanium Grade 1 after welding by hollow cathode arc discharge in vacuum and related changes in the corrosion behaviour of the weldments. Design/methodology/approach: Macro and microstructure of weldments were studied using optical microscopy. Corrosion behaviour of untreated Grade 1 and heat-affected zone of weldments of Grade 1 was investigated using electrochemical testing, including open circuit potential measurements and potentiodynamic polarisation. As an aggressive environment, 1 M KBr water solution was used. Findings: Welding by hollow cathode arc discharge in vacuum leads to the formation of a coarse Widmanstätten structure in the heat-affected zone. This imperfect structure results in a passive layer with worsened protective properties, thus increasing the corrosion rate of weldments by up to two orders of magnitude compared to Grade 1 in as-received condition. The passive layer on the welded surfaces did not allow Grade 1 to acquire a stable corrosion potential during potenitodynamic polarization. Research limitations/implications: Titanium and its alloys are passivating metallic materials, and their corrosion resistance depends on the properties of a thin protective surface layer. Changes in the underlying metal microstructure can affect the passivation behaviour of titanium and the properties of this layer. Welding by hollow cathode arc discharge in vacuum alters the microstructure of heat-affected zone, thereby causing Widmanstätten microstructure to form. As the passive layer over that microstructure has worsened protective properties, we suggest additional heat treatment after welding to be applied. Future experimental research on this topic is needed. Originality/value: Welding by hollow cathode arc discharge in vacuum is a welding method allowing weldments to be done in a clean environment and even in space. In the specialised literature, information on the structure and corrosion resistance of weldments of commercially pure titanium Grade 1 welded by hollow cathode arc discharge in vacuum is missing. The present research fills in a tiny part of this gap in our knowledge.

SURFACE ANALYSIS OF MICRO-ARC OXIDIZED COATINGS DEPOSITED ON cp-Ti

2009 ◽  
Vol 23 (31n32) ◽  
pp. 3717-3723
Author(s):  
YEON-WOOK KIM ◽  
TAE-HYUN NAM
Keyword(s):  
Pore Size ◽  
Current Density ◽  
Pure Titanium ◽  
Rutile Phase ◽  
Passive Layer ◽  
Commercially Pure Titanium ◽  
Applied Current ◽  
Oxidation Treatment ◽  
Applied Current Density ◽  
Titanium Grade

The surface of commercially pure titanium (grade 4) was modified by micro-arc oxidation treatment. A porous TiO 2 coating layer was formed on the Ti surface and its crystal structure was analyzed as rutile phase. Both the thickness of the TiO 2 layer and the pore size on the surface were strongly dependent on the applied current density as well as the micro-arc oxidizing time during the oxidation treatment. When a current density of 50 mA/cm2 had been applied for 10 minutes, the thickness and the pore size of the oxide layer were 1.2 µm and 230 nm, respectively. The thickness and the pore size of the layer continued to increase with increasing the applied current density. The TiO 2 passive layer of the titanium surface can attribute to the excellent biocompatibility and the formation of nano-sized pores may maximize the interlocking between mineralized bone and the surface of the Ti implant.

UPM CP TITANIUM GRADE 3 (UNS R50550)

Alloy Digest ◽  
2020 ◽  
Vol 69 (6) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Pure Titanium ◽  
Heat Treating ◽  
Commercially Pure Titanium ◽  
Commercially Pure ◽  
Continuous Service ◽  
Pure Grade ◽  
Grade 3 ◽  
Titanium Grade ◽  
Design Stress

Abstract UPM CP Titanium Grade 3 (UNS R50550) is an unalloyed commercially pure titanium that exhibits moderate strength (higher strength than that of Titanium Grade 2), along with excellent formability and corrosion resistance. It offers the highest ASME allowable design stress of any commercially pure grade of titanium, and can be used in continuous service up to 425 °C (800 °F) and in intermittent service up to 540 °C (1000 °F). This datasheet provides information on composition, physical properties, and elasticity. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Ti-167. Producer or source: United Performance Metals.

Homogeneity of Bulk Nanostructured Titanium Obtained by Hydrostatic Extrusion

2011 ◽  
Vol 674 ◽  
pp. 47-51 ◽  
Author(s):  
Krzysztof Topolski ◽  
Halina Garbacz ◽  
Wacław Pachla ◽  
Krzysztof J. Kurzydlowski
Keyword(s):  
Grain Size ◽  
Pure Titanium ◽  
Hydrostatic Extrusion ◽  
Equivalent Diameter ◽  
Commercially Pure Titanium ◽  
Average Grain Size ◽  
Size Diversity ◽  
Titanium Grade ◽  
Bulk Nanocrystalline ◽  
Nano Grains

The aim of this study was to investigate the homogeneity of the bulk nanocrystalline titanium rods obtained by Hydrostatic Extrusion (HE). The investigated material was commercially pure titanium grade 2. The final products of extrusion were nanocrystalline rods with diameters of 7 and 10 mm and lengths of about 250 mm. The size and shape of the grains were examined on transverse sections using transmission electron microscopy (TEM). The grain size was determined by the average grain equivalent diameter d2. The grain size diversity was quantified in terms of the equivalent diameter coefficient of variation CV (d2). The samples for the microscopic analyses were cut from various regions of the rods i.e. top, end, centre, and from surface of the rods. In all the samples, the average grain size determined on transverse sections was about 70 nm and the nano-grains in the various regions of the rods were similar in the shape. The examinations demonstrated that the nanostructure of the extruded rods was homogeneous. This observation was confirmed by the results of microhardness measurements.

scholarly journals The Effects Of Friction On Stamping Process Of Sheet Metals Used In Aviation

2015 ◽  
Vol 60 (3) ◽  
pp. 1895-1900 ◽  
Author(s):  
K. Dyja ◽  
W. Więckowski
Keyword(s):  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Spherical Cap ◽  
Drawing Test ◽  
Commercially Pure ◽  
Stamping Process ◽  
Strip Drawing ◽  
Titanium Grade ◽  
The Impact ◽  
Lubrication Conditions

Abstract An important factor in the possibility of obtaining correct drawn parts with the desired functional properties is the friction between the stamped sheet and the tool. The article discusses the impact of technological lubricants developed according to our own formulas, based on vegetable oils, on the stamping process taking into account the strain distributions in the drawn parts. Biodegradable lubricants based on rapeseed oil with an addition of stearic acid or boric acid were used. The results of the friction coefficient in a strip drawing test and the numerical analysis results of the stamping process of a spherical cap from sheet metal: aluminium 2024, commercially pure titanium Grade 2, steel 5604 in dry friction and lubrication conditions, are presented. Strain distributions and changes in the drawn part wall thickness were analysed.

Photocatalytic activity and antibacterial efficacy of UVA-treated titanium oxides

2020 ◽  
Vol 35 (4-5) ◽  
pp. 500-514
Author(s):  
Haden Andrew Johnson ◽  
Randall Scott Williamson ◽  
Mary Marquart ◽  
Joel David Bumgardner ◽  
Amol V Janorkar ◽  
...  
Keyword(s):  
Photocatalytic Activity ◽  
Pure Titanium ◽  
Antimicrobial Properties ◽  
Bacterial Attachment ◽  
Mixed Phase ◽  
Titanium Oxides ◽  
Commercially Pure Titanium ◽  
Mixed Acid ◽  
Uva Irradiation ◽  
Titanium Grade

Studies have shown ultraviolet-A (UVA) irradiation of crystalline titanium oxides leads to the production of reactive oxygen species (ROS) via a photocatalytic process. The ROS exhibit antimicrobial properties that may be of benefit in preventing bacterial attachment to implant devices. Recent studies have suggested a potential benefit of mixed anatase and rutile oxides and dopants on the photocatalytic properties of titanium oxides. The goal of this work was to compare the photocatalytic activity of different anodized commercially pure titanium grade 4 (CPTi4) surfaces. CPTi4 specimens were anodized in three mixed-acid electrolytes to create crystalline oxide surfaces that were either primarily anatase, primarily rutile, or a combination of anatase and rutile. Additionally, the primarily anatase and combination oxides incorporated some phosphorous from the phosphoric acid component in the electrolyte. The photocatalytic activity of the anodized specimens was measured using both methylene blue (MB) degradation assay and comparing the attachment of S. aureus under irradiation with UVA light of differing intensities (1 mW/cm2, 8 mW/cm2, and 23 mW/cm2). Primarily rutile oxides exhibited significantly higher levels of MB degradation after exposure to 1 mW/cm2 UVA lights. Primarily rutile specimens also had the largest reduction in bacterial attachment followed by the mixed phase specimens and the primarily anatase specimens at 1 mW/cm2 UVA lights. Phosphorous-doped, mixed phase oxides exhibited an accelerated MB degradation response during exposure to 8 mW/cm2 and 23 mW/cm2 UVA lights. All anodized and unanodized CPTi4 groups revealed similar S. aureus attachment at the two higher UVA intensities. Although MB degradation assay and the bacteria attachment assay both confirmed photocatalytic activity of the oxides formed in this study, the results of the MB degradation assay did not accurately predict the oxides performance against S. aureus.

scholarly journals Thromboinflammation as bioactivity assessment of H2O2-alkali modified titanium surfaces

2019 ◽  
Vol 30 (6) ◽  
Author(s):  
Gry Hulsart-Billström ◽  
Oscar Janson ◽  
Håkan Engqvist ◽  
Ken Welch ◽  
Jaan Hong
Keyword(s):  
Platelet Aggregation ◽  
Complement Activation ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Coagulation Activation ◽  
Commercially Pure ◽  
A Cell ◽  
Modified Surface ◽  
Titanium Surfaces ◽  
Titanium Grade

Abstract The release of growth factors from platelets, mediated by the coagulation and the complement system, plays an important role in the bone formation around implants. This study aimed at exploring the thromboinflammatory response of H2O2-alkali soaked commercially pure titanium grade 2 discs exposed to whole human blood, as a way to assess the bioactivity of the discs. Commercially pure titanium grade 2 discs were modified by soaking in H2O2, NaOH and Ca(OH)2. The platelet aggregation, coagulation activation and complement activation was assessed by exposing the discs to fresh whole blood from human donors. The platelet aggregation was examined by a cell counter and the coagulation and complement activation were assessed by ELISA-measurements of the concentration of thrombin-antithrombin complex, C3a and terminal complement complex. The modified surface showed a statistically significant increased platelet aggregation, coagulation activation and complement activation compared to unexposed blood. The surface also showed a statistically significant increase of coagulation activation compared to PVC. The results of this study showed that the H2O2-alkali soaked surfaces induced a thromboinflammatory response that indicates that the surfaces are bioactive.

A study of argon metastable generation in a hollow cathode arc

1984 ◽  
Vol 62 (2) ◽  
pp. 141-147
Author(s):  
Marc Fortin ◽  
Paul Meubus
Keyword(s):  
Hollow Cathode ◽  
Potential Energy Curve ◽  
Arc Discharge ◽  
Rare Gas ◽  
Energy Curve ◽  
Helium Mixture ◽  
Wavelength Scale ◽  
Gas Molecules ◽  
Cathode Arc ◽  
Radiation Measurements

A study is made of the intense spectroscopic continuum obtained between 120 and 180 nm for an argon–helium mixture (15% He) deexcitation, the emission originating from a hollow cathode arc discharge operated at 2900 K and a calculated pressure of 20 kPa. The deexcitation of the excimers toward the repulsive fundamental level gives way to an ultraviolet (UV) continuum, which is a characteristic of the potential energy curve for these molecules and whose position in the wavelength scale depends on the temperature of the hollow cathode. This continuum is identified as the second Tanaka continuum.Absolute radiation measurements have been made with a gold coated photocathode in order to determine the excited rare gas molecules [Formula: see text] concentration, which is in the order of 7 × 1013 cm−3.Such concentrations are high and seem to be related to the generation means used (hollow cathode).The spectroscopic results obtained with the indicated specific argon–helium mixture imply a major contribution of a precursor of the type (He–Ar)+ for the [Formula: see text] metastable formation.

Evaluation of Elastic Properties of CP Ti by Three Different Techniques

2015 ◽  
Vol 830-831 ◽  
pp. 195-198
Author(s):  
K. Saravanan ◽  
Bhal Sumit ◽  
P.L. Nithilaksh ◽  
P. Ramesh Narayanan
Keyword(s):  
Elastic Constants ◽  
Pure Titanium ◽  
Ultrasonic Pulse ◽  
Test Methods ◽  
Stressed Condition ◽  
Commercially Pure Titanium ◽  
Static Tensile ◽  
Titanium Grade ◽  
Cp Ti ◽  
Pulse Echo

Elastic constants are the fundamental key parameters in the mechanical behaviour of engineering materials under stressed condition. This paper explains the determination of elastic constants of commercially pure titanium (Grade-2) at ambient temperature using three independent test methods including quasi-static tensile test with strain gauged specimen, ultrasonic pulse echo method and resonance based impulse excitation technique. The results are statistically analysed and compared.

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