Heat load behaviors of plasma sprayed tungsten coatings on copper alloys with different compliant layers

Properties of tungsten coating deposited onto copper by high-speed atmospheric plasma spraying

“…Overall, the oxygen contents increase with the input power, but the values are very small. These results are similar to what has been achieved with VPS-W coating [12,13]. HAPS-W technique can reduce the oxidation of tungsten mainly due to the high velocities of the powder particles and the rapid solidification of the droplets.…”

“…It exhibited a slightly poorer adhesion in comparison with the reported result of the VPS-W coating [10,11,13]. In theory, HAPS-W should be able to obtain better coating adhesion because of the higher flight velocity of particles.…”

Vacuum annealing enhances the properties of a tungsten coating deposited on copper by atmospheric plasma spray

“…However, when studied under the same annealing conditions, steel was found to suffer minimal reduction in microhardness, suggesting that replacing copper with steel as the substrate could solve this problem. The adhesion of the coating was measured to be around 15 MPa both before and after annealing, smaller than that of VPS-W coatings reported in the literature [12][13][14]. This is most likely due to smaller particle size, which means lower kinetic energy and higher residual stress [6].…”

“…It is clear that vacuum annealing drastically reduced the oxygen content of the APS-W coating, resulting in a value that matches or is even below the one measured for VPS-W coatings [5,12]. In both cases the microhardness is significantly higher in the middle than near the substrate or air interfaces.…”

High heat load properties of actively cooled W/CuCrZr mock-ups by diffusion bonding with Ni or Ti interlayer

“…Recently, A W/Cu mock-up of explosive joining with no interlayer has been manufactured and tested in ASIPP, however, delaminations took place under about 6-7 MW/m 2 due to large stresses [15]. And tungsten coating were successfully deposited on copper alloy by plasma spray method in ASIPP [16]. Diffusion bonding is an alternative method for joining similar and dissimilar materials, which results in almost no phase transformation or microstructural change during the process because the bonding temperature can be as low as half of the joined materials' melting points.…”