脉冲加热惰气熔融-红外/热导法测定镍基高温合金粉末中氧和氮

镍基高温合金粉末中氧和氮对镍基高温合金综合性能有重要影响.采用氧氮氢联用分析仪对镍基高温合金粉末中氧、氮含量同时测定的方法进行研究.探讨分析功率、助熔剂、石墨坩埚、镍箔质量与称样量组合对测试结果的影响,推荐合适的测试条件.结果 表明:分析功率为5.5 kW时,样品完全熔融,释放曲线峰形对称且无拖尾;0.2g镍箔作为助熔...

Determination of oxygen and nitrogen in nickel-based superalloy powder by pulse heating inert gas fusion infrared absorption/thermal conductivity method

Oxygen and nitrogen in nickel-based superalloy powder has an important influence on the comprehensive properties of nickel-based superalloy. The method for simultaneous determination of oxygen and nitrogen in nickel-based superalloy powder was studied using an oxygen-nitrogen-hydrogen analyzer. The effect of analysis power, flux, graphite crucible, combination of nickel foil mass and sample mass on the test results was discussed. The suitable test conditions were recommended. The results showed that the sample could be completely fused when the analytical power was 5.5 kW. The peak shape of the release curve was symmetrical without tailing. As 0.2 g of nickel foil was used as a flux, the fusion state was good and it was soft to easily seal the sample. The use of duplex graphite crucible was conducive to the uniform heating of the sample, reducing the penetration rate and improving the stability of the test results. Considering that the sample should to be fully fused to ensure good stability of the test results, 0.2 g of nickel foil was used as flux for about 0.4 g of sample. Finally, 0.4 g of sample wrapped with 0.2 g of nickel foil were put into a duplex graphite crucible for testing under the analytical power of 5.5 kW. The limit of detection of oxygen was 0.000 3%, and the limit of quantification was 0.001 0%. The limit of detection of nitrogen was 0.000 15% and the limit of quantification was 0.000 5%. The measurement results of oxygen and nitrogen contents of the standard samples were all within the extended uncertainty range of the standard value. The relative error of oxygen and nitrogen was less than 9% and 6%, respectively. The recoveries of oxygen and nitrogen were 96%-102% and 95%-105%, respectively. The relative standard deviations (RSD, n=7) of the testing results of oxygen and nitrogen contents in three samples were all below 7%.