TZM合金真空烧结脱氧的机制分析

研究添加活性金属元素和碳的TZM钼合金在真空烧结后氧元素的变化,通过热力学计算和分析研究钼合金的脱氧机制。结果表明:在粉末冶金TZM烧结过程中,主要有两种脱氧机制:(1)碳还原体系中的金属氧化物生成金属碳化物和CO;(2)MoO2在真空高温下发生歧化反应生成金属Mo和MoO3气体,MoO3气体被真空系统抽出。提高炉内真空度和降低产物气体的分压可降低脱氧反应进行的温度,有利于脱氧。

Deoxidation Mechanism of TZM Molybdenum Alloys during Vacuum Sintering

The change of oxygen was studied for the TZM molybdenum alloys with addition of active metal element and carbon after vacuum sintering. The mechanism of deoxidation of molybdenum alloys was analyzed through the thermodynamic calculation. The results show that in the sintering process of powder metallurgical TZM, there are two kinds of deoxidation mechanisms. One is that metal oxide compound in TZM react with the carbon to produce CO and metal carbide; the other is that the disproportionting reaction of MoO2 occurs at high temperature to produce metal Mo and MoO3 gas and the gas is drawn out by the vacuum system. Improving the vacuum degree of the furnace and reducing the partial pressure of product gas can decrease reaction temperature and is good for deoxidation.