Determination of chemical composition of nickel-based super alloy by TOF-PGA technique

TOF-PGA法を用いたNiベース超合金の元素分析

Huang, M.; 藤 暢輔   ; 海老原 充*; 木村 敦   ; 中村 詔司  

Huang, M.; Toh, Yosuke; Ebihara, Mitsuru*; Kimura, Atsushi; Nakamura, Shoji

Nickel-based super alloys are found in a wide range of applications, such as the manufacture of gas turbine military aircraft, power generation and marine propulsion. These kinds of alloys generally have complicated chemical compositions. In many studies, their compositions were determined by X-ray fluorescence (XRF) method since the alloys were not destroyed before testing their properties. However, XRF cannot detect the deep layer of alloys (typically under 0.1-mm depth). Therefore, thick alloys are hardly examined directly by XRF. Prompt gamma-ray analysis (PGA) and neutron resonance capture analysis (NCRA) are well-known non-destructive methods which are applicable to thick samples. Unfortunately, PGA is not very sensitive to some elements (e.g. Nb) and NCRA lacks of sensitivity to some light elements. At J-PARC ANNRI, the two methods have been combined as a new analytical method, TOF-PGA, which overcomes the disadvantages of PGA and NCRA. It is feasible to apply the new method to the examinations on materials with complicated chemical compositions. In this study, concentrations of Ni, Cr, Ti, Co, Al, B in two nickel-based super alloys were determined by PGA while W, Ta, Mo, Nb, Re, Ru and Hf were quantitatively analyzed by TOF analysis or TOF-PGA. The accurate results of present study show that the TOF-PGA technique is a powerful tool for the composition analysis on super alloys.