유리/다공성 알루미나의 접촉하중에 의한 기계적 거동 |
김철, 김상겸, 김태우, 이기성 |
국민대학교 기계시스템공학부 기계설계전공 |
Mechanical Behavior of Glass/Porous Alumina by Contact Loading |
Chul Kim, Sang Kyum Kim, Tae Woo Kim, Kee Sung Lee |
School of Mechanical Systems Engineering, Kookmin University |
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ABSTRACT |
Porous alumina with different porosities, 5.2 - 47.5%, were coated with cover-glass having a thickness of $160{mu}m$, using epoxy adhesive. We investigated the effect of the porosity of the substrate layer on the crack initiation load, and the size of cracks propagated in the coating layer. Hertzian indentations were used to evaluate the damage behavior under a constrained loading condition. Typically, two types of cracks, ring cracks and radial cracks, were observed on the surface of the glass/porous alumina structure. Indentation stress-strain curves, crack initiation loads, crack propagation sizes, and flexural strengths were investigated as a function of porosities. The results indicated that a porosity of less than 30% and a higher substrate elastic modulus were beneficial at suppressing cracks occurrence and propagation. We expect lightweight mechanical components with high strength can be successfully fabricated by coating and controlling porosities in the substrate layer. |
Key words:
Porous alumina, Contact loading, Hertzian indentation, Mechanical behavior |
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