Development and properties of high thermal conductivity molybdenum carbide - graphite composites

Guardia-Valenzuela, J.; Bertarelli, A.; Carra, Federico; Mariani, Nicola; Bizzaro, S.; Arenal, Raúl

doi:10.1016/j.carbon.2018.04.010

Cited by 59 publications

(39 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…A family of novel graphite-based composites reinforced with a dispersion of molybdenum-carbide particles, referred to as Molybdenum-Carbide Graphite (MoGr), with very high thermal and electrical properties, was recently developed at CERN, in collaboration with Brevetti Bizz (IT), for the upgraded primary and secondary collimators. This material, produced by spark plasma sintering, assisted by liquid phase, has been extensively investigated and characterized [18].…”

Section: Considered Materials Choices For Collimationmentioning

confidence: 99%

See 1 more Smart Citation

Resistivity Characterization of Molybdenum-Coated Graphite-Based Substrates for High-Luminosity LHC Collimators

et al. 2020

Self Cite

View full text Add to dashboard Cite

The High-Luminosity Large Hadron Collider (HL-LHC) project aims at extending the operability of the LHC by another decade and increasing by more than a factor of ten the integrated luminosity that the LHC will have collected by the end of Run 3. This will require doubling the beam intensity and reducing the transverse beam size compared to those of the LHC design. The higher beam brightness poses new challenges for machine safety, due to the large energy of 700 MJ stored in the beams, and for beam stability, mainly due to the collimator contribution to the total LHC beam coupling impedance. A rich research program was therefore started to identify suitable materials and collimator designs, not only fulfilling impedance reduction requirements but also granting adequate beam-cleaning and robustness against failures. The use of thin molybdenum coatings on a molybdenum–graphite substrate has been identified as the most promising solution to meet both collimation and impedance requirements, and it is now the baseline choice of the HL-LHC project. In this work we present the main results of the coating characterization, in particular addressing the impact of coating microstructure on the electrical resistivity with different techniques, from Direct Current (DC) to GHz frequency range.

show abstract

Section: Considered Materials Choices For Collimationmentioning

confidence: 99%

“…Adhesion of the coating was tested in a pull test and showed no delamination of the Mo coating. In particular, a rupture in the MoGr planes occurred at around 6 MPa, but never at the interface between the Mo coating and the MoGr substrate [30], which is close to the through-plane strength of the bulk material [18].…”

Section: Sputtering Coating Techniquesmentioning

confidence: 99%

Resistivity Characterization of Molybdenum-Coated Graphite-Based Substrates for High-Luminosity LHC Collimators

et al. 2020

Self Cite

View full text Add to dashboard Cite

show abstract

“…The prototype jaws allow testing three different approaches. The jaws are made of MoGr grade MG-6403Fc [25] and one 10 mm wide surface of uncoated material and two 10 mm wide coating stripes of Mo-the baseline coating of secondary collimators-and titanium nitride (TiN) with ρ ¼ 400 μΩm-for additional reference measurements ( Fig. 3, right).…”

Section: Prototype Low-impedance Collimatormentioning

confidence: 99%

“…Since the operational collimator openings cannot be significantly relaxed, it is therefore planned to change the material of the collimators with the highest contributions to the impedance. The present upgrade baseline foresees to replace 9 out of 11 secondary and 2 out of 4 primary collimators per beam [17] with new collimators using jaws made of a novel low-impedance material [25].…”

mentioning

confidence: 99%

Transverse beam stability with low-impedance collimators in the High-Luminosity Large Hadron Collider: Status and challenges

Antipov

Accettura

Amorim

et al. 2020

Phys. Rev. Accel. Beams

View full text Add to dashboard Cite

The High-Luminosity LHC Project aims to increase the integrated luminosity that will be collected by the Large Hadron Collider for the needs of the high energy physics frontier by the end of its Run 3 by more than a factor ten. This will require doubling the beam intensity, and in order to ensure coherent stability until the brighter beams are put in collision, the transverse impedance of the machine has to be reduced. As the major portion of the ring impedance is generated by its collimation system, several low resistivity jaw materials have been considered to lower the collimator impedance and a special collimator has been built and installed in the machine to study their effect. In order to assess the performance of each material we performed a series of tune shift measurements with LHC beams. The results show a significant reduction of the resistive wall tune shift with novel materials, in good agreement with the impedance model and the bench impedance and resistivity measurements. The largest improvement is obtained with a molybdenum coating of a molybdenum-graphite jaw. This coating, applied to the most critical collimators, is estimated to lower the machine impedance by up to 30% and the stabilizing Landau octupole threshold by up to 240 A after accounting for uncertainties of the model and other destabilising effects. A half of the overall improvement can be obtained by coating the jaws of a subset of 4 out of 11 collimators identified as the highest contributors to machine impedance. This subset of low-impedance collimators is being installed during the Long

show abstract

“…Graphite, as a kind of promising material, is extensively used in many industrial applications because of its extraordinary thermal and chemical stabilities, and low thermal expansion . For instance, a recent report on graphite nanoplatelets‐based epoxy showed high thermal conductivity via casting method .…”

Section: Introductionmentioning

confidence: 99%

Effects of graphite and boron nitride based fillers on mechanical, thermal conductive, and thermo‐physical properties in solution styrene–butadiene rubber

Fan

Cho

2018

Polymer Composites

View full text Add to dashboard Cite

In the present work, graphite and hexagonal boron nitride (BN) are studied as fillers in order to reinforce physical properties of the solution styrene–butadiene rubber (SSBR). Composites based on SSBR and these two fillers are prepared via kneading followed by hot compression method, and these two hybrid fillers with different wt% into the SSBR composites are also produced. The effects of different wt% on the morphology, tensile strength, thermal conductivity, and thermal properties are investigated. From the test results, using each of the filler can increase the mechanical properties and thermal conductivity, whereas the effectiveness of graphite remarkably increased the tensile strength and thermal conductivity. The composites of the hybrid filler systems have better mechanical performance compared to the SSBR filled with BN, and they are all inferior to the SSBR filled with graphite. In addition, the test showed that the thermal conductivity of the composites of the hybrid filler systems is comparable with SSBR filled with BN. POLYM. COMPOS., 40:E1426–E1433, 2019. © 2018 Society of Plastics Engineers

show abstract

Development and properties of high thermal conductivity molybdenum carbide - graphite composites

Cited by 59 publications

References 15 publications

Resistivity Characterization of Molybdenum-Coated Graphite-Based Substrates for High-Luminosity LHC Collimators

Resistivity Characterization of Molybdenum-Coated Graphite-Based Substrates for High-Luminosity LHC Collimators

Transverse beam stability with low-impedance collimators in the High-Luminosity Large Hadron Collider: Status and challenges

Effects of graphite and boron nitride based fillers on mechanical, thermal conductive, and thermo‐physical properties in solution styrene–butadiene rubber

Contact Info

Product

Resources

About