高频感应燃烧红外线吸收法测定镍钛铌记忆合金中碳含量

建立高频感应燃烧–红外吸收测定镍钛铌记忆合金中碳含量的方法。对称样质量、助熔剂种类选择及加入量、空白坩埚的处理、仪器分析参数进行优化后,确定实验方案:称样质量0.5 g,助熔剂选用1.0 g钨锡粒,坩埚使用前于1 100℃中灼烧4 h后自然冷却,保存于干燥器中,仪器分析高频功率设定为1.54 k W。在选定的实验条件下,以钢铁标准样品绘制单点校准曲线,以钛合金标准物质IARM 271A验证曲线准确性,建立了高频燃烧红外吸收测定镍钛铌记忆合金中碳含量的方法。采用该方法分别对记忆合金样品NiTiNb–59炉、NiTiNb–40炉中碳含量进行测定,测定结果的相对标准偏差分别为3.42%,2.76%(n=10),在两样品中分别加入Leco501–501–1~#及AR871碳标准样品进行回收试验,回收率在96%~106%之间。该方法精密度好,准确性高,可用于镍钛铌记忆合金中碳含量的测定。

Determination of Carbon Content in NiTiNb Memory Alloy by High Frequency Combustion Infrared Absorption Method

The method of high frequency combustion infrared to determinate content of carbon in NiTiNb memory alloy was established. After optimizing the mass of sample, the type and amount of fluxe, treatment of blank crucibles and analysis parameters, analysis procedure was as follows: the mass of sample was 0.5 g, the fluxe was 1.0 g tungsten-tin, crucibles were burned 4 h in muffle furnace at 1 100℃, cooled, conserve in a covered container before using, high-power of instrument was set at 1.54 kW. Under the selected experimental conditions, the single point calibration curve was drawn by steel standard material and confirmed by titanium alloy standard material IARM 271A. Under the optimized experimental conditions, the content of carbon in NiTiNb–59 and NiTiNb–40 memory alloy was analyzed, the relative standard deviation of determination results was 3.42%, 2.76%(n=10), the recovery was 96%–106% by using Leco501–501–1# and AR871 added in NiTiNb–59 and NiTiNb–40 samples separately. This method is suitable for determination of carbon content in NiTiNb memory alloy with good precision and high accuracy.