Piezo-spectroscopic and tribological characterization of diffusion bonded oxide laminate composite ceramics

Abstract

AbstractThis study is focused on mechanical and tribological performance with phase and crystal structure studies of diffusion bonded dense α-alumina laminates with chemically activated Al–Sr mixed hydride (SrH2/Sr2AlH7) nano-particles as the interlayer by developing a controlled interlayer for preparing oxide laminate composites with high fracture toughness and enhanced wear resistance. Shear bond strength and four-point bending tests indicated a maximum strength of 174 and 189 MPa for hot pressed alumina/Sr2AlH7, with a transgranular fracture mechanism under shear stress. The difference in the coefficient of thermal expansion between the composites layers resulted in the development of residual stresses in alumina and interlayer. The magnitude and the distribution of these micro and macro residual stresses were assessed by the piezo-spectroscopic technique. The effects of residual stress on fracture toughness and the friction coefficient of laminates were studied.