Mechanical characterization and modeling of the heavy tungsten alloy IT180

Scapin, Martina

doi:10.1016/j.ijrmhm.2015.01.018

Cited by 39 publications

(16 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The investigation in compression was limited since the reachable level of strain is much lower than in tension, but nevertheless increasing the strain means also to increase the friction, which is difficult to be taken into account during data elaboration. As widely discussed in [21], to perform tests in compression at high temperature, especially in dynamic regime, is more critical due to the small dimensions of the specimens. For these reasons for the data analysis the results coming from compression tests were not used.…”

Section: Resultsmentioning

confidence: 99%

“…The high strain-rate tests were performed using Split Hopkinson Bar setups in direct configuration. A more in depth description of the testing setups can be found in [21][22][23]. In the tests at elevated temperature, both in quasistatic and dynamic regime, the specimen was heated using an induction coil system, controlled with a feedback on the temperature measurement obtained using thermocouples directly welded on the specimen surface (see Fig.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Investigation and Mechanical Modelling of Pure Molybdenum at High Strain-Rate and Temperature

Scapin

Peroni

Carra

2016

J. dynamic behavior mater.

Self Cite

View full text Add to dashboard Cite

This work shows the results obtained from the investigation of the mechanical behavior of two batches of pure molybdenum specimens (C99.97 % Mo, Mo1 supplied by Plansee and Mo2 supplied by AT&M) under static and dynamic loading conditions at different temperatures, both under tensile and compressive loading conditions. Due to its properties molybdenum has applications in several fields including nuclear. At this moment, it is a good candidate for structural material application for Beam Intercepting Devices of the Large Hadron Collider at CERN, Geneva. The experimental tests in tensile loading condition were performed on small dog-bone specimens. A series of tests at room temperature and a range of strainrates was performed in order to obtain information about the strain-rate sensitivity of the material. A series of tests at different temperatures in both static and high dynamic loading conditions was performed in order to obtain information about the thermal softening of the material. The dynamic tests were performed using the Hopkinson Bar technique, and the heating of the specimen was performed using an induction coil system. The experimental tests in compression were carried out on cylindrical specimens at room temperature and a range of strain-rates. The experimental data were analyzed via a numerical inverse method based on Finite Element numerical simulations.This approach allows to obtain the effective stress versus strain curves, which cannot be derived by using standard relations since instability and necking were present. Moreover, it also allows the non-uniform distribution of strain-rate and temperature inside the specimen to be accounted for. The results obtained from compression tests confirm the data obtained in tension in terms of strainhardening and strain-rate sensitivity, even if the material exhibits a tension-compression asymmetry of the behavior. The analysis of the hardening, temperature and strain-rate sensitivities reveals that a unique standard visco-plastic model could not be defined to reproduce the material strength behavior under different loading conditions, especially over wide range of variation of the variables of interest.Keywords Refractory metal Á High temperature Á High strain-rate Á Hopkinson bar Á Tensile and compression Á Nuclear applications Á Instability Á FE-based numerical inverse approach

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Investigation and Mechanical Modelling of Pure Molybdenum at High Strain-Rate and Temperature

Scapin

Peroni

Carra

2016

J. dynamic behavior mater.

Self Cite

View full text Add to dashboard Cite

show abstract

“…In order to derive the evolution of pressure, temperature, and density in the blocks of the jaw, an appropriate equation of state (EOS) must be adopted. In these simulations, a tabular EOS for tungsten has been used for Inermet-180 [38][39][40]. The behavior of the material beyond the elastic regime is usually accounted for by a strength model, while its structural limits are determined through a convenient failure model: in these simulations the Johnson-Cook strength model [39] and the minimum hydrostatic pressure were adopted [41].…”

Section: Thermomechanical Studiesmentioning

confidence: 99%

“…In these simulations, a tabular EOS for tungsten has been used for Inermet-180 [38][39][40]. The behavior of the material beyond the elastic regime is usually accounted for by a strength model, while its structural limits are determined through a convenient failure model: in these simulations the Johnson-Cook strength model [39] and the minimum hydrostatic pressure were adopted [41]. The applied models were compared with data from dedicated experiments at the CERN HiRadMat facility, where a pulsed proton beam impacted collimator materials on a test bench.…”

Section: Thermomechanical Studiesmentioning

confidence: 99%

Modeling of beam-induced damage of the LHC tertiary collimators

Quaranta

Redaelli

Lechner

et al. 2017

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

Modern hadron machines with high beam intensity may suffer from material damage in the case of large beam losses and even beam-intercepting devices, such as collimators, can be harmed. A systematic method to evaluate thresholds of damage owing to the impact of high energy particles is therefore crucial for safe operation and for predicting possible limitations in the overall machine performance. For this, a three-step simulation approach is presented, based on tracking simulations followed by calculations of energy deposited in the impacted material and hydrodynamic simulations to predict the thermomechanical effect of the impact. This approach is applied to metallic collimators at the CERN Large Hadron Collider (LHC), which in standard operation intercept halo protons, but risk to be damaged in the case of extraction kicker malfunction. In particular, tertiary collimators protect the aperture bottlenecks, their settings constrain the reach in β Ã and hence the achievable luminosity at the LHC experiments. Our calculated damage levels provide a very important input on how close to the beam these collimators can be operated without risk of damage. The results of this approach have been used already to push further the performance of the present machine. The risk of damage is even higher in the upgraded high-luminosity LHC with higher beam intensity, for which we quantify existing margins before equipment damage for the proposed baseline settings.

show abstract

“…A series of different solutions are analyzed and good results, in terms of correlation between experimental and predicted responses, are obtained when the experimental data at temperature over 400 • C in quasi-static condition are omitted from the optimization process. In the optimization all the available repetitions are taken into account for the determination of 6 unknown (a more in-depth description of the procedure is reported in [9]). The optimized parameters are summarized in Table 2.…”

Section: Epj Web Of Conferencesmentioning

confidence: 99%

Experimental investigation of the behaviour of tungsten and molybdenum alloys at high strain-rate and temperature

Scapin

Fichera

Carra

et al. 2015

EPJ Web of Conferences

Self Cite

View full text Add to dashboard Cite

Abstract. The introduction in recent years of new, extremely energetic particle accelerators such as the Large Hadron Collider (LHC) gives impulse to the development and testing of refractory metals and alloys based on molybdenum and tungsten to be used as structural materials. In this perspective, in this work the experimental results of a tests campaign on Inermet R IT180 and pure Molybdenum (sintered by two different producers) are presented. The investigation of the mechanical behaviour was performed in tension varying the strain-rates, the temperatures and both of them. Overall six orders of magnitude in strain-rate (between 10 −3 and 10 3 s −1 ) were covered, starting from quasi-static up to high dynamic loading conditions. The high strain-rate tests were performed using a direct Hopkinson Bar setup. Both in quasi-static and high strain-rate conditions, the heating of the specimens was obtained with an induction coil system, controlled in feedback loop, based on measurements from thermocouples directly welded on the specimen. The temperature range varied between 25 and 1000 • C. The experimental data were, finally, used to extract the parameters of the Zerilli-Armstrong model used to reproduce the mechanical behaviour of the investigated materials.

show abstract

Mechanical characterization and modeling of the heavy tungsten alloy IT180

Cited by 39 publications

References 26 publications

Investigation and Mechanical Modelling of Pure Molybdenum at High Strain-Rate and Temperature

Investigation and Mechanical Modelling of Pure Molybdenum at High Strain-Rate and Temperature

Modeling of beam-induced damage of the LHC tertiary collimators

Experimental investigation of the behaviour of tungsten and molybdenum alloys at high strain-rate and temperature

Contact Info

Product

Resources

About