COATING BY WIRE EXPLOSION SPRAYING (II): Structure and Adhesion of Tungsten Coatings on the Mild-Steel and Copper Substrate
Year: 1975
Type: article
Abstract: The coating method and the characteristics of wire explosion spraying developed in our laboratory are described.The mechanism of adhesion between the coating and substrate in two metal systems, W-mild steel and W-Cu which differ in mutual solubility, is studied.Metallographic observations using EPMA and soft X-ray confirmed the presence of a solid solution boundary layer in the case of the mild steel substrate, and a critical shearing stress of adhesion measured by our method ranged from 20 to 26 kg/mm 2 , which is nearly equal to the shearing strength of the tungsten coating itself of 24 kg/mm 2, and the fracture propagated within the coating itself.In the case of the copper substrate the critical shearing stress of adhesion was 9 to 13 kg/mm 2 which is much weaker than the shearing strength of copper, 28 kg/mm 2, and the fracture propagated along the boundary between the coating and the substrate.Theoretical considerations attempt to explain the mechanisms of formation of the structures and the adhesion properties.It is concluded that the high adhesion strengths obtained by this method are attributable to the characteristics of the particles sprayed by wire explosion, i.e., the small size of average 5 µ, the high temperature of near the boiling point of materials, the high impinging velocity of 500~600 m /sec, and furthermore the uniformities of the size, velocity and temperature of the sprayed particles.
DOI: 10.5109/7173572
Authors: Toshiro SUHARA, Kazunori KITAJIMA, Shigehisa FUKUDA, Hiroshi ITO, Hiroki FUKUNAGA
Language: English
Subfield: Mechanical Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4403788314