| 摘要 |
PURPOSE: An etching method of Ti - Nb - X group titanium alloy is provided to clearly observe grain boundary by reducing over-etching phenomenon which is presented when etching sample after heat treatment. CONSTITUTION: An etching method of Ti - Nb - X group titanium alloy etches by soaking alloy in etchant including 2 - 15 wt% of nitric acid(HNO3), 1 - 20 wt% of hydrofluoric acid(HF), and rest water. If an alloy material is heat-treated, the ally etches by soaking in etchant including 3 - 10 wt% of HNO3, 1 - 10 wt% of HF, and rest water. In an immersion process, the etchant is stirred for 2-15 second. The etchant which is adhered in the immersion process is completely removed through rinse step between immersion process while repeating the immersion process. X is one kind or more which is selected from Zr, Ge, Si, V, Ta and Sn. |
