本文介绍了利用线形同轴耦合式微波等离子体CVD法在硬质合金微型钻头(微钻)上沉积金刚石涂层的初步实验结果。微型钻头的直径为0.5mm,其中WC晶粒的尺寸约为0.5μm。在沉积前,先用Murakam i溶液(10gKOH+10gK3[Fe(CN)6]+100m l H2O)对微...本文介绍了利用线形同轴耦合式微波等离子体CVD法在硬质合金微型钻头(微钻)上沉积金刚石涂层的初步实验结果。微型钻头的直径为0.5mm,其中WC晶粒的尺寸约为0.5μm。在沉积前,先用Murakam i溶液(10gKOH+10gK3[Fe(CN)6]+100m l H2O)对微钻刻蚀10m in,使其表面粗化,然后用硫酸-双氧水溶液(10m l98wt%H2SO4+100m l 38%m/vH2O2)对其浸蚀60 s,以去除其表面的Co。在金刚石涂层过程中发现,由于微钻尖端在微波电磁场中产生较集中的辉光放电现象,因而在微钻尖端很难获得金刚石涂层。针对这种金刚石涂层过程中的“尖端效应”,尝试使用了金属丝屏蔽的方法以改变微钻周围的微波电磁场分布,克服了上述金刚石涂层过程中的“尖端效应”,首次成功地采用微波等离子体CVD法在微钻上沉积了厚度为1.5μm的金刚石涂层。展开更多
考察了消解方式、消解酸体系、升温时间和目标温度对样品消解效果的影响,提出了微波消解-电感耦合等离子体原子发射光谱法(ICP-AES)同时测定钛及钛合金中Fe、Si、Mn、Mo、B、Al、Sn、Cr、V、Zr、Mg、Nb、Pd、Ni、Ta、W、Nd、Ru、Cu等19...考察了消解方式、消解酸体系、升温时间和目标温度对样品消解效果的影响,提出了微波消解-电感耦合等离子体原子发射光谱法(ICP-AES)同时测定钛及钛合金中Fe、Si、Mn、Mo、B、Al、Sn、Cr、V、Zr、Mg、Nb、Pd、Ni、Ta、W、Nd、Ru、Cu等19种元素含量的方法。取0.1000 g钛及钛合金样品置于聚四氟乙烯消解罐中,再加入8.0 mL 33%(体积分数)盐酸溶液、3.0 mL 25%(体积分数)氢氟酸溶液、1.0 mL 50%(体积分数)硝酸溶液和0.5 mL高氯酸,将其置于微波消解仪于最高消解温度120℃下保持10 min,冷却至室温,用水将消解液定容至50 mL,采用ICP-AES测定质量分数不大于1.0%的元素,将样品溶液稀释10倍,同法测定质量分数大于1.0%的元素。结果表明,19种元素的质量浓度在一定范围内与对应的响应强度呈线性关系,检出限(3s)为0.006~0.033 mg·L^(-1)。对4种钛合金标准样品和3种钛合金实际样品进行分析,并与标准方法GB/T 4698系列的测定结果进行对比,结果显示本方法的测定值与认定值基本一致。以两种钛合金标准样品和两种钛合金实际样品为研究对象进行精密度试验,每个样品平行测定5次,测定值的相对标准偏差均小于4.0%。展开更多
Two microwave digestion procedures were developed for unleaded gasoline. Microwave plasma torch atomic emission spectrometry(MPT-AES) was used to determine trace lead in unleaded gasoline after being digested. Optimal...Two microwave digestion procedures were developed for unleaded gasoline. Microwave plasma torch atomic emission spectrometry(MPT-AES) was used to determine trace lead in unleaded gasoline after being digested. Optimal conditions (analytical wavelength, microwave power, flow rate of carrier gas for the trace lead determination, flow rate of supporting gas, flow rate of oxygen shielding gas and acid concentrations) were chosen. The effects of concommitant elements on determination of lead were studied. The detection limit for lead was 25 ng/mL, the linear range was 0.05-100 μg/mL. The relative standard deviation for determination of unleaded gasoline samples was less than 4 9%, relative error was less than 3.7%. Standard addition recoveries were all between 93.3%-104.0%. The determination results with microwave digestion were in agreement with those obtained with conventional method. The proposed method is simple, rapid, accurate, and with less possibility to be contaminated by the environment, and of great applied value.展开更多
文摘本文介绍了利用线形同轴耦合式微波等离子体CVD法在硬质合金微型钻头(微钻)上沉积金刚石涂层的初步实验结果。微型钻头的直径为0.5mm,其中WC晶粒的尺寸约为0.5μm。在沉积前,先用Murakam i溶液(10gKOH+10gK3[Fe(CN)6]+100m l H2O)对微钻刻蚀10m in,使其表面粗化,然后用硫酸-双氧水溶液(10m l98wt%H2SO4+100m l 38%m/vH2O2)对其浸蚀60 s,以去除其表面的Co。在金刚石涂层过程中发现,由于微钻尖端在微波电磁场中产生较集中的辉光放电现象,因而在微钻尖端很难获得金刚石涂层。针对这种金刚石涂层过程中的“尖端效应”,尝试使用了金属丝屏蔽的方法以改变微钻周围的微波电磁场分布,克服了上述金刚石涂层过程中的“尖端效应”,首次成功地采用微波等离子体CVD法在微钻上沉积了厚度为1.5μm的金刚石涂层。
文摘考察了消解方式、消解酸体系、升温时间和目标温度对样品消解效果的影响,提出了微波消解-电感耦合等离子体原子发射光谱法(ICP-AES)同时测定钛及钛合金中Fe、Si、Mn、Mo、B、Al、Sn、Cr、V、Zr、Mg、Nb、Pd、Ni、Ta、W、Nd、Ru、Cu等19种元素含量的方法。取0.1000 g钛及钛合金样品置于聚四氟乙烯消解罐中,再加入8.0 mL 33%(体积分数)盐酸溶液、3.0 mL 25%(体积分数)氢氟酸溶液、1.0 mL 50%(体积分数)硝酸溶液和0.5 mL高氯酸,将其置于微波消解仪于最高消解温度120℃下保持10 min,冷却至室温,用水将消解液定容至50 mL,采用ICP-AES测定质量分数不大于1.0%的元素,将样品溶液稀释10倍,同法测定质量分数大于1.0%的元素。结果表明,19种元素的质量浓度在一定范围内与对应的响应强度呈线性关系,检出限(3s)为0.006~0.033 mg·L^(-1)。对4种钛合金标准样品和3种钛合金实际样品进行分析,并与标准方法GB/T 4698系列的测定结果进行对比,结果显示本方法的测定值与认定值基本一致。以两种钛合金标准样品和两种钛合金实际样品为研究对象进行精密度试验,每个样品平行测定5次,测定值的相对标准偏差均小于4.0%。
文摘Two microwave digestion procedures were developed for unleaded gasoline. Microwave plasma torch atomic emission spectrometry(MPT-AES) was used to determine trace lead in unleaded gasoline after being digested. Optimal conditions (analytical wavelength, microwave power, flow rate of carrier gas for the trace lead determination, flow rate of supporting gas, flow rate of oxygen shielding gas and acid concentrations) were chosen. The effects of concommitant elements on determination of lead were studied. The detection limit for lead was 25 ng/mL, the linear range was 0.05-100 μg/mL. The relative standard deviation for determination of unleaded gasoline samples was less than 4 9%, relative error was less than 3.7%. Standard addition recoveries were all between 93.3%-104.0%. The determination results with microwave digestion were in agreement with those obtained with conventional method. The proposed method is simple, rapid, accurate, and with less possibility to be contaminated by the environment, and of great applied value.
