Fabrication and characterization copper/diamond composites for heat sink application using powder metallurgy

Abstract

Copper composites reinforced with diamond particles were fabricated by the powder metallurgical technique. Copper matrix and diamond powders were mixed mechanically, cold com- pacted at 100 bar then sintered at 900?C. The prepared powders and sintered copper/diamond composites were investigated using X-ray diffraction (XRD) and scanning electron microscope equipped with an energy dispersive X-ray analysis (SEM/EDS). The effect of diamond contents in the Cu/diamond composite on the different properties of the composite was studied. On fracture surfaces of the Cu/uncoated diamond composites, it was found that there is a very weak bonding between diamonds and pure copper matrix. In order to improve the bonding strength between copper and the reinforcement, diamond particles were electroless coated with NiWB alloy. The results show that coated diamond particles distribute uniformly in copper composite and the interface between diamond particles and Cu matrix is clear and well bonded due to the formation of a thin layer from WB2, Ni3B, and BC2 between Cu and diamond interfaces. The properties of the composites materials using coated powder, such as hardness, transverse rupture strength, thermal conductivity, and coefficient of thermal expansion (CTE) were exhibit greater values than that of the composites using uncoated diamond powder. Additionally, the results reveals that the maximum diamond incorporation was attained at 20 Vf%. Actually, Cu/20 Vf% coated diamond com- posite yields a high thermal conductivity of 430 W/mK along with a low coefficient of thermal expansion (CTE) 6 × 10–6/K

An experimental investigation of bonding strengths for plasma facing components

“…[14][15][16][17][18] Considering the properties of diamond/Cu composite, it was a promising candidate to enhance the bonding strength of W/CuCrZr. 9-13 Diamond/Cu composite was one of the widely studied heat sink composites.…”

“…[9][10][11][12][13] Diamond/Cu composite was one of the widely studied heat sink composites. [14][15][16][17][18] Considering the properties of diamond/Cu composite, it was a promising candidate to enhance the bonding strength of W/CuCrZr. Actually, Wang et al 19,20 have conducted a lot of work to study the effects of different coating film, sintering temperatures, and volume fractions of diamond particles to the thermal conductivity of diamond/Cu composites.…”

Microstructural and wear characterizations of Ultra-Dispersed Diamond (UDD) reinforced Cu-15 wt.% Ti composites fabricated via mechanical alloying and sintering

“…[8,[21][22][23]. It was reported [8,9] that the strong bonding between diamond and copper was obtained with the addition of Ti and this led to heat and load transfer increment. Titanium was used as an interfacial binder in a number of studies in order to improve the interfacial bonding strength between the copper matrix and SiC [24,25], diamond [26].…”

“…These limitations are often circumvented by dispersing a stronger ceramic material in the copper matrix. In the literature, Al 2 O 3 [2,3], NbC [4], Fe 3 C [5], SiC [6], diamond [7][8][9] have commonly been used as reinforcements for Cu matrix. Among these, nanodiamond particles are quite attractive due to their unique mechanical and tribological properties, including extreme hardness and inertness to chemical attack [10][11][12].…”

Tribological study of hot pressed oxide dispersion strengthened 2205 DSS composite

“…ODS plays a crucial role in determining the mechanical properties of the composite. An ideal interface should provide good adhesion and minimum boundary resistance (Hamid, Moustafa, Morsy, Khalifa & Mouez, 2011).…”