scholarly journals Synchronized Full-Field Strain and Temperature Measurements of Commercially Pure Titanium under Tension at Elevated Temperatures and High Strain Rates

Metals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 25
Author(s):  
Guilherme Corrêa Soares ◽  
Mikko Hokka

Understanding the mechanical behavior of materials at extreme conditions, such as high temperatures, high strain rates, and very large strains, is fundamental for applications where these conditions are possible. Although tensile testing has been used to investigate material behavior under high strain rates and elevated temperatures, it disregards the occurrence of localized strains and increasing temperatures during deformation. The objective of this work is to combine synchronized full-field techniques and an electrical resistive heating system to investigate the thermomechanical behavior of commercially pure titanium under tensile loading at high temperatures and high strain rates. An electrical resistive heating system was used to heat dog-bone samples up to 1120 °C, which were then tested with a tensile Split Hopkinson Pressure Bar at strain rates up to 1600 s−1. These tests were monitored by two high-speed optical cameras and an infrared camera to acquire synchronized full-field strain and temperature data. The displacement and strain noise floor, and the stereo reconstruction error increased with temperature, while the temperature noise floor decreased at elevated temperatures. A substantial decrease in mechanical strength and an increase in ductility were observed with an increase in testing temperature. The localized strains during necking were much higher at elevated temperatures, while adiabatic heating was much lower or non-existent at elevated temperatures.

2020 ◽  
Vol 87 (9) ◽  
Author(s):  
Xuchen Wang ◽  
Mostafa Hassani

Abstract With the advent of advanced testing techniques such as laser-induced particle impact test, it is possible to study materials mechanics under extremely high deformation rates, i.e., above 106 s−1, a relatively less explored regime of strain rates. Inspired by the classical Taylor impact test, in this study, we accelerate microparticles of commercially pure titanium to a range of impact velocities, from 144 to 428 m/s, toward a rigid substrate and record their deformation upon impact in real-time. We also conduct finite element modeling of the experimentally recorded impacts using two constitutive equations, namely, Johnson–Cook and Zerilli–Armstrong. We show that the titanium microparticles experience strain rates in the range of 106–1010 s−1 upon impact. We evaluate the capability of the Johnson–Cook and Zerilli–Armstrong equations in predicting the deformation response of pure Ti at ultra-high strain rates. With an optimization-based constitutive modeling approach, we also propose updated strain rate-related parameters for both equations and improve the extent to which the two models can describe the deformation of pure titanium at ultra-high strain rates.


Alloy Digest ◽  
1979 ◽  
Vol 28 (12) ◽  

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.


2012 ◽  
Vol 548 ◽  
pp. 174-178 ◽  
Author(s):  
Chong Yang Gao ◽  
Wei Ran Lu

By using a dislocation-based plastic constitutive model for hcp metals developed by us recently, the dynamic thermomechanical response of an important industrial material, commercially pure titanium (CP-Ti), was described at different temperatures and strain rates. The constitutive parameters of the material are determined by an efficient optimization method for a globally optimal solution. The model can well predict the dynamic response of CP-Ti by the comparison with experimental data and the Nemat-Nasser-Guo model.


1986 ◽  
Vol 72 (2) ◽  
pp. 321-328 ◽  
Author(s):  
Takehide SENUMA ◽  
Hiroshi YADA ◽  
Hirobumi YOSHIMURA ◽  
Hisaaki HARADA ◽  
Takuji SHINDO ◽  
...  

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