Deposition of tungsten coatings by detonation spraying

Tungsten is a promising material for plasma-facing components of thermonuclear reactors. In the present work, tungsten coatings of low residual porosity (1%) were deposited on copper substrates by detonation spraying. Calculations of the particle temperatures and velocities were conducted for tungsten particles of different sizes using a previously developed model. These calculations helped selecting the spraying parameters enabling the formation of high-quality tungsten coatings in the experiments. A proper selection of the stand-off distance allowed achieving a high deposition efficiency of the powder (60%). The coatings showed a high bonding strength to the copper substrates, which was found to be 100 MPa, and a high hardness (850 HV). The coatings were shown to accumulate compressive stresses, which are beneficial for the structural integrity of coatings up to 500 mu m thick.

Automated summary

Tungsten coatings with low residual porosity were successfully deposited on copper substrates using detonation spraying, with high bonding strength and hardness. By calculations and experiments, suitable spraying parameters were selected to achieve high-quality coatings, showing potential for plasma-facing components of thermonuclear reactors.