화학공학소재연구정보센터
Materials Science Forum, Vol.423-4, 125-130, 2003
Graded ceramics for improved contact-damage resistance
The concept of elastic-modulus-graded ceramics for improved resistance to quasi-static contact damage (Hertzian-indentation) is reviewed. Here, the in-plane elastic modulus is low at the contact surface and high in the interior (substrate) with a continuous, or stepwise continuous, gradation in between. Processing strategies for fabricating such graded ceramic composites in the Al2O3-glass, the Si3N4-glass, and the Si3N4-SiC Systems are described. The Hertzian indentation behavior and wear properties of these composites are presented. Some modeling results are also presented, and are used to discuss the role of elastic-modulus gradients and thermal-expansion residual stresses in imparting contact-damage resistance to these composites.