3D printing of diamond reinforced metal matrix composites for thermal management applications – 3DCOMPOSITE

High-power electronic devices, such as supercomputers, generate considerable heat. If this heat is not transferred away from the device’s internal circuitry, the circuits will overheat, significantly reducing the lifetime of the device, causing faults and total device failure. Thermal management materials featured by tailored thermal properties are used to dissipate heat away from device circuitry. However, current substrate materials are restricted by their properties and/or high cost of manufacturing. This proposed project will explore the feasibility to cost-effectively produce a metal/diamond composite with a high thermal conductivity by using 3D printing technology. This research aims at both advancing fundamental understanding of 3D-printed metal matrix composites and the development of improved manufacturing technologies, particularly for copper/diamond and aluminium/diamond composites via interface engineering.

This joint project puts together excellence of the four laboratory partners: ICMCB Université de Bordeaux/CNRS, UMET Université de Lille, ICB-LERMPS Université de Technologie Belfort-Montbéliard, and I2M Université de Bordeaux/CNRS. 3 SMEs agreed to participate to this project: 1) Lifco Industry subcontractor for thin film deposition of a small batch of diamond powder by PVD, 2) BV Proto which will potentially benefit from the outcome of the project linked with possible optimization of SLM machine and 3) Minapack Technologies which already fabricate and commercialize MMC materials for heat sink applications and which will potentially be interested in the intellectual properties developed during this project.

The objectives and research hypothesis in the three main work packages are detailed below:

WP1 : focus on advancing fundamental understanding for determining how the interphase characteristics affect interfacial thermal conductance (ITC) and thermophysical properties of the 3D-printed metal/diamond composites. A model metal (Al and Cu)/carbide-forming-element interlayer/diamond structure, similar to actual interfaces in the metal/diamond composites, will be prepared using physical vapour deposition (PVD) and/or other proper techniques and further annealing. Direct measurement of ITC values, using a modulated photothermal radiometry technique, will be performed on such model materials and correlated with the interphase structure characterized by electron microscopy. Kinetics of the model materials during the SLM process will be stimulated using a “home-made 3D printer.

WP2 : focus on technological advancement by developing a scalable and cost-effective sol-gel (and PVD)/satelliting process to produce a diamond core-shell powder coated with fine metal (Cu and Al) alloy particles for 3D printing using a commercial SLM machine; Interface tailoring and homogenous integration of the diamond particles in the SLM-processed component will be simultaneously figured out by introducing a nanoscale carbide-forming-element interlayer in between the diamond core and Al (or Cu) outer layer; identify the relationship between 3D printing process and metal/diamond composites’ microstructure and thermophysical properties (e.g. density, TC).

WP3: focus on revealing detailed interphase configurations of the metal/interlayer/diamond composite powders and components and the model materials, such as the geometry, bonding, chemistry and structural defects and interfacial reactions, by using in-depth characterization at length scales from the micro down to nano- and/or atomic scales. Correlate interphase as well as matrix microstructure with thermophysical properties to develop an understanding of the mechanism of microstructure formation during the 3D printing process.