Ultra-low temperature fabrication of copper carbon fibre composites by hydrothermal sintering for heat sinks with enhanced thermal efficiency

Abstract

Highlights:  Dense Cu/40CF composite are fabricated by low temperature hydrothermal sintering at 265 °C and 250 MPa with 5 wt.% water.  Thermal properties of Cu/40CF composite materials fabricated by low temperature hydrothermal sintering are isotropic 2  Hydrothermal sintering increases thermal conductivity and reduces coefficient of thermal expansion in comparison to uniaxial hot pressing  Hydrothermal sintering improves mechanical hardness of Cu/40CF composite materials in comparison to uniaxial hot pressing

Metal Matrix Composite in Heat Sink Application: Reinforcement, Processing, and Properties

“…Copper is the most widely used matrix material for heat sink applications due to its high thermal conductivity (400 Wm −1 K −1 ), high melting temperature, and good weldability [ 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 ]. To overcome the high coefficient of thermal expansion of copper, different reinforcements have been incorporated in the copper matrix, namely diamond particles [ 36 , 38 , 39 , 40 , 41 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 , 58 , 59 , 60 , 61 , 62 , 63 , 64 , 65 , 66 , 67 ], graphite (particles, fibers, or foam) [ 44 , 68 , 69 , 70 ], carbon fibers (CFs) [ 39 , 54 , 71 , 72 , 73 ], carbon nanotubes (CNTs) […”

“…In order to overcome anisotropy in properties, cross-ply composites were fabricated, but the thermal conductivities obtained in the in-plane and transverse directions (i.e., 150 and 50 Wm −1 K −1 , respectively) were below 300 Wm −1 K −1 [ 95 ]. Novel hydrothermal sintering successfully yielded an approximate isotropic thermal conductivity of 300 Wm −1 K −1 with 40% volume fraction of copper-coated carbon fibers [ 73 ].…”

“…The developed microstructure determines the thermo-mechanical properties of the composite. The consolidated composite is available to be fabricated into final product through secondary thermo-mechanical processing like rolling, forging, or extrusion [ 22 , 39 , 73 , 151 ]. Hot press sintering, pulsed electric current sintering (PECS), and microwave sintering were reported to consolidate MMCs fabricated for heat sink applications.…”

“…An acceptable thermal performance is observed by reinforcing CNTs in copper by electrodeposition [ 75 ]. Carbon fibers have also been reinforced in copper [ 39 , 73 ] and aluminum [ 39 , 131 , 132 ] matrices, but the composites did not demonstrate an acceptable thermal performance. Hybridizing composites can be an effective alternative.…”

Innovative High-Pressure Fabrication Processes for Porous Biomaterials—A Review

“…The various mechanism perceived for the cold sintering is attributed to particle dissolution and reprecipitation, plastic deformation and hydrothermal-type process [51][52][53][54][55][56]. Various high pressure processing techniques used for materials processing are given in Table 1 [6,53,[57][58][59][60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76], mainly at elevated temperature for various level of pressure regarding the technologies used. The porous structure can be obtained by applying pressure for short time duration and/or lower temperature compensated by higher pressure (acting as driving Force) in these HP processes after the initiation of the necks, to avoid densification.…”