燃烧-气体容量法测定WC-Ni-Al粉末中总碳含量的研究

Determination of Total Carbon Content in WC-Ni-Al Powder by Combustion Gas Volumetric Method

硬质合金以Ni_3Al替代传统硬质合金中的粘结相Co的研究已取得较大进展,提高主成份碳含量的精确控制是制取优质硬质合金的关键。本文用传统的YHC-86型高碳测定仪,采用燃烧-气体容量法检测以Ni_3Al为粘结相的硬质合金粉末中的总碳含量。对助熔剂用量、样品熔融温度、燃烧分析时间及氧气流量,混合气体的吸收速度等工作条件进行实验,总结出最佳的分析条件:在不加助熔剂的条件下,控制炉子温度为1 250~1 300℃,氧气流量为400~450 ml/min,样品燃烧时间为3 min±10 s,混合气体吸收速度为14~18 s。在该条件下WC-Ni-AL样品分析精度良好,重复测量的标准偏差为0.013%,相对标准偏差为0.29%,碳量回收率为98.70%~100.78%。

Great progress has been made on the use of Ni_3Al to replace the binder phase cobalt in conventional cemented carbides. The key to produce high quality cemented carbide is to improve the precision control of carbon content.In this paper, the total carbon content of cemented carbide powder with Ni_3Al as binder phase was measured by combustion gas volumetric method with the traditional YHC-86 type high carbon analyzer. Experimental conditions such as reagent for improving the melting effect, sample melting temperature, oxygen flow rate of combustion analysis and absorption of mixed gas compression speed were investigated. The optimum analysis conditions are summarized as follows： there is no need to add reagents to promote melting, the furnace temperature is controlled to be 1 250 ℃ to 1 300 ℃, the oxygen flow rate is 400 ml/min, sample burning time is 3 min ± 10 s, mixed gas absorption rate is 14~18 s. Under this condition, the accuracy of WC-Ni-Al sample analysis is good, the standard deviation of repeated measurement is 0.013%, the relative standard deviation is 0.29%, and the carbon recovery rate is 98.70%~100.78%.