The Effect of Hf Addition on the Boronizing and Siliciding Behavior of CoCrFeNi High Entropy Alloys.

The effect of a boronizing and siliciding process on CoCrFeNiHf high entropy alloys was examined in this study. When increasing the amount of added Hf in CoCrFeNiHf, the structure of the alloys gradually transformed from single-phase FCC to firstly NiHf + FCC, and finally to C15 Laves and FCC phases. The boronizing/siliciding process resulted in the formation of a silicon-rich layer and a boride layer (BL).

Microarc oxidation discharge types and bio properties of the coating synthesized on zirconium.

This study is an attempt for gaining a better understanding on relationship between microarc oxidation (MAO) coating discharge types and bioactivity of an oxide-based coating synthesized on a Zr substrate. The discharge types and the coating growth mechanism were identified by the examination of the real cross-section image of the coating microstructure. The coating was conducted by using MAO in an electrolyte containing NaSiO, Ca(CHCOO) and CHNaOP, for different durations of 2.