Probing into the Yield Plateau Phenomenon in Commercially Pure Titanium During Tensile Tests

This research aims to study the behavior of monotonic and cyclic plastic deformation on commercially pure titanium which has undergone surface treatment using the nitrogen ion implantation method. The doses of 2.0×1017 ions/cm2 and the energy of 100 keV were used to implant the nitrogen ions into the CpTi. Monotonic properties tests were performed in a laboratory air and at room temperature using ASTM E8 standard specimens. Fatigue and corrosion fatigue tests were conducted in a laboratory air and in artificial saline solutions, at room temperature using ASTM 1801-97 specimens. Tensile tests were carried out with constant displacement rate and fatigue tests were carried under fully-reversed with stress-controlled conditions with stress amplitudes 230, 240, 250, 260, 270 and 280 MPa. The results showed the material properties of monotonic behavior for CpTi and Nii-Ti; tensile strength (σu) of 497 and 539 MPa and for 0.2% offset yield strength (σy) of 385 and 440 MPa, respectively and of cyclic behavior; cyclic strength coefficient (k’) of 568.41 and 818.64 and cyclic strain hardening exponent (n’) of 0.176 and 0.215, respectively. This study has succeeded in producing useful new material properties that will contribute to the field of material science and engineering.

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Improvement in Ductility in Commercially Pure Titanium Alloys by Stress Relaxation at Room Temperature

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.611-612.92 ◽

2014 ◽

Vol 611-612 ◽

pp. 92-98 ◽

Cited By ~ 11

Author(s):

Irena Eipert ◽

Giribaskar Sivaswamy ◽

Rahul Bhattacharya ◽

Muhammad Amir ◽

Paul Blackwell

Keyword(s):

Stress Relaxation ◽

Titanium Alloys ◽

Yield Point ◽

Room Temperature ◽

Pure Titanium ◽

Tensile Tests ◽

Tensile Behaviour ◽

Strain Rates ◽

Commercially Pure Titanium ◽

Commercially Pure

Present work focusses on the effect of stress relaxation on the tensile behaviour of two commercially pure titanium alloys of different strength levels (Grade 1 and Grade 4) subjected to tensile tests at room temperature. The stress relaxation tests were performed by interrupting the tensile tests at regular strain intervals of 5% in the plastic region of the tensile curve and compared to the monotonic tensile tests at different strain rates ranging from 10-4to 10-1s-1. To understand the effect of anisotropy, samples were taken along 0° and 90° to rolling direction (RD) for both the alloys. Improvement in ductility of different levels at all the strain rates was observed in both the alloys when stress relaxation steps were introduced as compared to monotonic tests. However there is not much change in the flow stress as well as in strain hardening behaviour of the alloys. The true stress-true strain curves of Grade 4 samples taken in 90° to RD exhibited discontinuous yielding phenomenon after the yield point, which is termed as a yield-point elongation (YPE). The improvement in ductility of the Cp-Ti alloys can be linked to recovery process occurring during the stress relaxation steps which resulted in the improvement in ductility after repeated interrupted tensile tests. The paper presents and summarise the results based on the stress relaxation for the two different alloys.

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Tensile properties of α-titanium alloys at elevated temperatures

MATEC Web of Conferences ◽

10.1051/matecconf/202032104016 ◽

2020 ◽

Vol 321 ◽

pp. 04016

Author(s):

Tarik Nawaya ◽

Werner Beck ◽

Axel von Hehl

Keyword(s):

Titanium Alloys ◽

Tensile Properties ◽

Oxidation Resistance ◽

Elevated Temperatures ◽

Pure Titanium ◽

High Strength ◽

Tensile Tests ◽

Commercially Pure Titanium ◽

Commercially Pure ◽

Gleeble 3500

Hot-deep drawing is an innovative processing technology to produce complex shaped sheet metal components with constant wall thickness from high-strength lightweight materials. For some aerospace and automotive applications oxidation resistance at medium to high temperatures is an important aspect. In terms of this titanium α-alloys are often used due to their balanced relation of strength and oxidation resistance. In the presented study the stress-strain characteristics of several α-titanium alloys were determined at ambient and elevated temperatures by means of hot tensile tests. Besides the commercially pure Titanium alloy ASTM-Grade 4, two novel α-titanium alloys were investigated. Regarding the hot forming properties a comparison with α-β Ti-6Al-4V alloy was conducted. The hot tensile tests were carried out by means of a particular forming dilatometer type “Gleeble 3500” at 400, 500, 600, 650, 700 and 800 °C. The test showed favorable peak plasticity for all α-alloys at the temperature range between 600 and 650 °C in contrast to lower or higher temperatures. All samples were metallographically characterized. Key words: titanium α-alloys, hot tensile properties, elevated temperatures, Gleeble 3500.

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RMI 0.2% Pd

Alloy Digest ◽

10.31399/asm.ad.ti0074 ◽

1979 ◽

Vol 28 (12) ◽

Keyword(s):

Corrosion Resistance ◽

Crevice Corrosion ◽

Elevated Temperatures ◽

Pure Titanium ◽

Heat Treating ◽

Low Ph ◽

Commercially Pure Titanium ◽

Bend Strength ◽

Commercially Pure ◽

Minimum Yield

Abstract RMI 0.2% Pd is a grade of commercially pure titanium to which up to 0.2% palladium has been added. It has a guaranteed minimum yield strength of 40,000 psi with good ductility and formability. It is recommended for corrosion resistance in the chemical industry and other places where the environment is mildly reducing or varies between oxidizing and reducing. The alloy has improved resistance to crevice corrosion at low pH and elevated temperatures. This datasheet provides information on composition, physical properties, elasticity, tensile properties, and bend strength. It also includes information on corrosion resistance as well as forming, heat treating, machining, joining, and surface treatment. Filing Code: Ti-74. Producer or source: RMI Company.

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UPM CP TITANIUM GRADE 3 (UNS R50550)

Alloy Digest ◽

10.31399/asm.ad.ti0167 ◽

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.

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