Material and geometrical design for high reliability bilayer

Abstract

Ceramic/metal, ceramic/ceramic, and ceramic/polymer bilayers are prepared to find the best design for a reliable material. The transparent bilayer enables in situ observation of crack initiation. The elastic modulus of the substrate material in the bilayer is controlled from 2.35 GPa to 230 GPa by using different compositions of glass, metal, and polymer. The thickness of the ceramic coating layer is controlled from 120 μm to 5.6 mm. The surface of the coating material is abraded to control the strength and toughness. Classical cone cracks and transverse radial cracks are observed during Hertzian indentation. The crack initiations depend on not only material design parameters such as strength, toughness, and elastic modulus but also geometrical parameters such as coating thickness. Conditions for avoiding cracking are considered, in terms of the material and geometrical design parameters.

Correlation of microstructure with hardness and wear resistance in (TiC,SiC)/stainless steel surface composites fabricated by high-energy electron-beam irradiation

“…[1][2][3][4] However, when these materials are repeatedly exposed to severe conditions of high temperature, impact, and corrosive environment, fracture or separation occurs at interfaces between the metal and ceramic, and causes problems during actual applications. In response to these problems, studies have been made to obtain the desired surface compositions and microstructures by using a laser beam on ceramics such as TiN, TiC, and SiC.…”