化学镀镍-磷合金镀层中磷的测定

准确、简便地测定镍-磷合金镀层的磷对化学镀镍工艺具有重要作用.采用浓硝酸退镀镍-磷合金镀层→高锰酸钾氧化→亚硝酸钠还原→加水定容的方法制备实验溶液,然后分别用磷钼钒黄分光光度法、磷钼酸铵容量法分析试液中的磷,再换算出镀层中磷的质量分数,并与标准方法测定结果对比.结果表明:光度法测定的相对误差为7.93％,相对标准偏差为4.38％;容量法测定的相对误差为-1.83％,相对标准偏差为0.82％.容量法具有准确、简便的优点,可在生产实际和实验研究中推广应用.

Determination of Phosphorus Content in Electroless Ni-P Alloy Coating

The test solution was prepared by Ni-P coating stripping with concentrated nitric acid, oxidizing with potassium permanganate,reducing with sodium nitrite and watering to constant volume.Phosphorus concentration in the solution was determined by phosphorus molybdenum vanadium yellow spectrophotometry and ammonium phosphomolybdate volumetric method,and then converted to phosphorus content in the Ni-P coating and compared with that by standard method.Results showed that the relative error of spectrophotometry determination was 7.93%,the relative standard deviation of that was 4.38% while the relative error of volumetric method was -1.83%,the relative standard deviation of that was 0.82%.The volumetric method could be used in experimental research as well as in the field of production practices because of its simplicity and accuracy.