Interaction phenomena at refractory metals/ceramic interfaces

The objective of this study was to understand the interface chemical reactions between stable ceramics and reactive liquid metals, and developing microstructures. Experiments were conducted at elevated temperatures where small metal samples of Zr and Zr-alloy were placed on top of selected oxide and non-oxide ceramic substrates (Y 2O 3, ZrN, ZrC, and HfC). The sample stage was heated in high-purity argon to about 2000C, held in most cases for five minutes at the peak temperature, and then cooled to room temperature at 20C/min. An external video camera was used to monitor the in-situ wetting and interface reactions. Post-test examinations of the systems were conducted by scanning electron microscopy and energy dispersive spectroscopy. It was determined that the Zr and the Zr-alloy are very active in the wetting of stable ceramics at elevated temperatures. In addition, in some systems, such as Zr/ZrN, a reactive transition phase formed between the ceramic and the metal. In other systems, such as Zr/Y 2O 3, Zr/ZrC and Zr/HfC, no reaction products formed, but a continuous and strong joint developed under these circumstances also.

Interaction phenomena at refractory metals/ceramic interfaces Conference Paper