Fabrication and Characterization of ICP Sprayed Boron Carbide Coating on Tungsten Monoblock
Fabrication and Characterization of ICP Sprayed Boron Carbide Coating on Tungsten Monoblock
Abstract: Presently one of the most important tendencies is the use of tungsten monoblock material for the first wall and other plasma facing components (PFCs) in tokamak. The use of low Z materials such as B4C for protection of PFCs is a conventional method to decrease heavy impurity influx into tokamak plasma. This study involves the fabrication and characterization of inductively coupled plasma (ICP) thermal sprayed B4C coating on tungsten monoblock. Thickness of the coating is about 120μm. Surface morphology of the coating is presented with scanning electron microscope and metallographic microscope analyses. X-ray diffraction analysis and X-ray photoelectron spectroscopy showed that the main phase and chemical composition of the coatings were preserved when compared with that of the initial B4C powder. Pull-off test result revealed that the adhesion/cohesion strength of the coating was above 13.1 MPa. This work is innovative not only for the ICP thermal sprayed method for the B4C coating fabrication but for the plasma sprayed B4C on tungsten substrate.
Figure 1: Schematic drawing of the experiment system.
Key words: boron carbide coatings, tungsten substrate, ICP, thermal spray.