Influence of Cu2O and CuAlO2 Interphases on Crack Propagation at Cu/α-Al2O3 Interfaces |
| |
| Authors: | Ivar E. Reimanis Kevin P. Trumble Kirk A. Rogers Brian James Dalgleish |
| |
| Affiliation: | Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 87545;School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907;Center for Advanced Materials, Lawrence Berkeley Laboratory, Berkeley, California 94720 |
| |
| Abstract: | In-situ crack-propagation experiments, in conjunction with thermochemical experiments, have been used to examine the role of discontinuous interphases on the fracture behavior of solid-state diffusion-bonded Cu/α-Al2O3 couples. Clean, interphase-free interfaces exhibit crack extension by brittle decohesion at the crack tip at an initiation fracture energy of 125 J/m2. Crack propagation is characterized by an increase in the fracture energy with increases in the crack length ( R -curve behavior). When interfacial chemical reaction products are present, the crack growth is altered, depending on the characteristics of the interphase. The presence of Cu2O needles results in preferential debonding along the Cu2O/Al2O3 interface. On the other hand, finer CuAlo2 needles visibly impede crack propagation and result in a higher interface initiation fracture energy (}190 J/m2) than that of the interphase-free interface. The effects of the Cu2O and CuAlo2 phases on the fracture energy are discussed. |
| |
| Keywords: | |
|
|
