微波消解ICP-AES法测定镍基合金4种元素含量

Determining 4 elements in nickel-based alloys by microwave digestion ICP-AES method

镍基合金是一种在高温下具有良好耐腐蚀性及相当高强度的合金,在其成分分析中,存在样品难溶、分析测定不准等困难。研究比较了在不同混酸种类和配比条件下,采用传统湿法消解和现代微波消解2种溶样方式处理样品的不同。试验发现,采用HCl-HNO_(3)(10∶1)(体积比,下同)可将难溶镍基合金样品消解澄清,替代使用强腐蚀性HF作为助溶剂的消解方法。同时,考察了以Ni(60%)、Cr(22%)(质量分数,下同)为基体制作工作曲线对测定Co、Fe、Mn、Ti等元素的影响。结果表明,用少量HCl-HNO_(3)(10∶1)混酸为溶剂,采用微波消解处理样品时酸消耗量小、消解用时短、测定结果准确。用多元素混合标准系列溶液制作工作曲线,测定结果扣除镍铬基体空白后,与Inconel标准物质BS 625E(UNS Number N06625)认证值对比,相对误差在-10.6129%~8.7097%范围内,相对标准偏差为0.0629%~5.6864%。该法可准确测定难溶镍基合金中质量分数范围为0.001%~5%的Co、Fe、Mn、Ti等元素。研究结果可为冶金企业技术检测部门消解难溶镍基合金、测定合金中Co、Fe、Mn、Ti等元素提供可行的方法。

Nickel-based alloys are an alloy with both good corrosion resistance and considerable strength at high temperatures.In its composition analysis,there are difficulties such as difficult to dissolve samples and inaccurate analytical determination.The different was studied between the samples treated by traditional wet digestion and modern microwave digestion methods under different mixed acid types and ratios.It is found that the insoluble Ni-based alloy samples can be decomposed to clarified state by HCl-HNO_(3)(10∶1)(volume ratio,the same below),which can replace the decomposition method using strong corrosive HF as co-solvent.In addition,effect of making working curves with Ni(60%)and Cr(22%)(mass fraction,the same below)as substrates on the determination of Co,Fe,Mn,Ti and other elements was investigated.The results show that using small amount of HCl-HNO_(3)(10∶1)mixed acid as solvent and microwave digestion method to treat samples results in low acid consumption,short digestion time and accurate determination results.Working curves are produced using multi-element mixed standard series solutions and the results is obtained by subtracting the Ni-Cr matrix blank,then it is compared with the certified values of Inconel standard BS 625E(UNS Number N06625).The relative errors are in the range of-10.6129%to 8.7097%and relative standard deviations of 0.0629%to 5.6864%.The results shows that this method can accurately determine the mass fraction of Co,Fe,Mn,Ti and other elements in the insoluble nickel-based alloys in the range of 0.001%to 5%.The results can provide a feasible method for the digestion of insoluble Ni-based alloy and the determination of Co,Fe,Mn,Ti and other elements in the alloy.