Factors affecting explosive compaction–sintering of tungsten–copper coating on a copper surface

This study investigated the effects of detonation velocity, tungsten content, and tungsten particle size on the explosive compaction-sintering of tungsten-copper composite coatings on a copper surface. Tests were carried out using explosives with detonation velocities of 2500 m/s and 3500 m/s, and the theoretical density of the coating reached approximately 99% using explosives with a detonation velocity of 3500 m/s. The experimental results showed that detonation velocity had a significant effect on coating density, while tungsten content and particle size had little effect. Scanning electron microscopy (SEM) of the tungsten-copper coating indicated that the coarsening of tungsten grains was prevented by this method, and the morphologies of the coatings prepared with different tungsten contents and tungsten particle sizes were very different. X-ray diffraction (XRD) analysis of the tungsten-copper coating showed that no impurities were introduced during the preparation of the coating. Energy dispersive Xray spectroscopy (EDS) analysis results revealed that the content of tungsten and copper in the coating was consistent with the powder added in mechanical alloying. The Vickers hardness test showed that the more uniformly distributed the tungsten particles were, the more uniform the hardness of the coating. Different tungsten particle sizes lead to different fracture types, but the shear strengths between the coating and the substrate were very similar. The bonding strength between the W-50% wt. Cu coating and the substrate was approximately 110-125 MPa. (C) 2017 Elsevier B.V. All rights reserved.