Enhanced thermal conductivity in Diamond/Aluminum composites with tungsten coatings on diamond particles prepared by magnetron sputtering method

In the present work, tungsten (W) coatings with thickness range of 35-130 nm on the diamond particles were prepared by magnetron sputtering method, and then the Diamond/Al composites were prepared by the vacuum infiltration method. The prepared W coatings were smooth and dense on all the facets of the diamond particles. Moreover, the presence of W-coatings inhibited the interfacial debonding phenomenon and improved the interfacial bonding between diamond particles and Al matrix. The Diamond/Al composite with the 45 nm W-coating achieved the maximum thermal conductivity (622 W/(m.K)). To the best of our knowledge, it is the highest thermal conductivity obtained in the Al matrix composites reinforced with 100 mu m diamond particles with coatings. Based on the Hasselman and Johnson (H-J) model, the thermal conductivity behavior of the Diamond/Al composites has been discussed. It indicates that the magnetron sputtering is a feasible and successful method to prepare thin and reliable tungsten coatings for the Diamond/Al composites. (C) 2017 Elsevier B.V. All rights reserved.