Youngʹs modulus and residual stress of plasma-sprayed boron carbide coatings

This paper addresses the application of nondestructive evaluation techniques, such as the use of ultrasonic and X-ray techniques, for characterizing the quality of plasma-sprayed boron carbide coatings. The Youngʹs modulus and shear modulus of plasma-sprayed boron carbide coatings were measured by an ultrasonic echo technique. The residual stresses of coatings were determined by X-ray diffraction technique. The relationship between Youngʹs modulus and microstructure of the coatings is discussed. The results showed that the spraying distance has a significant effect on the phase composition and microstructure of boron carbide coatings. The elastic modulus of boron carbide coatings decreases with increasing spraying distance. This is explained by the increasing content of B2O3 and pores in the boron carbide coatings. The residual stresses of the coatings show a polynomial relationship with the spraying distance.