CERN Accelerating science

European Organization for Nuclear Research

Thermal Management Materials

Innovative Metal Matrix Composite for Thermal Management and Thermal Shock Applications

Description

The study of innovative Beam Intercepting Devices, in particular collimators, is essential to handle the high energy particle beams required to explore unknown territory in basic research. This calls for the development of novel advanced materials, as no existing metal-based or carbon-based material possesses the combination of physical, thermal, electrical and mechanical properties, imposed by the collimators extreme working conditions. New material families being investigated include metal-diamond and metal-graphite composites.

Combining the outstanding thermal and physical properties of diamond or graphite with the electrical and mechanical ones of metals and transition metal-based ceramics, these materials possess low density, high thermal conductivity, low coefficient of thermal expansion, high operating temperature and excellent thermal shock resistance. The research program carried out on these materials at CERN and collaborating partners is mainly focused on the theoretical investigation, material characterisation and manufacturing processes.

Besides High Energy Physics, these materials are of particular interest for demanding thermal management applications such as high power density electronic packaging, avionics and aerospace systems, gas turbines, advanced automotive and aeronautical braking systems. In the case of Molybdenum Carbide – Graphite composites, one can obtain a thermal conductivity of 770 W/mK, a coefficient of thermal expansion of less than 2 ppm/K, an electrical conductivity in excess of 1 MS/m and a density as low as 2.6 g/cubic cm. These, as well as other properties, can be tailored to meet specific application requests.

Area of expertise

Material Science.

Applications

Outside the High Energy Physics, these materials are of particular interest for thermal management applications such as high power density electronic packaging. The thermal conductivity of the materials used for the packaging of GaN (grown on SiC substrates) is currently limited to around 170-220 W/cmK as the CTE has to be close to 4 to 5 ppm/K (typically 5.6 to 8). The die are normally attached to a Au plated carrier (CuMoCu or CuW) using AuSn solder at around 280-300 deg C and operate with junction temperatures of 225 deg C. A material with a thermal conductivity of 700 & a CTE of 4 to 5 could be of interest also to the microwave device industry in general.

Additional fields of application may include aerospace, nuclear fusion, high-end braking systems, high power RF devices etc.

Advantages

  • Very high thermal conductivity.
  • Low coefficient of thermal expansion and good strength.
  • Excellent thermal shock resistance and very high operating temperatures.
  • Electric conductivity can be increased by applying a metallic cladding on the MMC surface.

Intellectual Property status

  • Collaborative R&D, licensing option can be discussed.

Contact person

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