论文部分内容阅读
利用三元系活度系数计算公式,计算了TiV15Al3Cr3Sn3(Ti-15-3)合金熔体中各组元的活度系数,计算结果表明,各组元的活度系数都小于1。利用活度的计算结果进一步研究了Ti-15-3合金真空熔炼时合金元素的挥发行为,结果表明,合金元素的挥发存在临界真空度,在超过这一真空度后合金元素的挥发损失加剧。建立了间隙元素在Ti-15-3合金中溶解的热力学模型,计算了氧在合金中的溶解度,并分析了影响氧元素在Ti-15-3合金中溶解度的因素。计算结果表明,熔炼室间隙元素分压是决定间隙元素含量的主要因素,并开发了降低间隙元素含量的工艺方法,试验结果与计算结果较符合。为了控制合金熔体温度,利用所开发的温度场计算程序,建立了ISM过程熔体温度与熔炼功率、炉料质量间的关系。利用该程序预测了ISM熔炼过程中凝壳形状及尺寸的变化过程,并对该过程进行了试验研究,计算结果与试验结果一致。
The activity coefficient of each component in the melt of TiV15Al3Cr3Sn3 (Ti-15-3) alloy was calculated by the calculation formula of activity coefficient of ternary system. The calculation results show that the activity coefficients of each component are all less than 1. The volatilization behavior of alloying elements in the vacuum melting of Ti-15-3 alloy was further studied by the calculation results of activity. The results show that there is a critical vacuum in the volatilization of alloying elements, and the volatilization loss of alloying elements is exacerbated when the vacuum degree is exceeded. The thermodynamic model for the dissolution of interstitial elements in Ti-15-3 alloy was established. The solubility of oxygen in the alloy was calculated and the factors affecting the solubility of oxygen in Ti-15-3 alloy were analyzed. The calculation results show that the partial pressure of the interstitial element in the melting chamber is the main factor that determines the interstitial element content, and the technological method of reducing the interstitial element content is developed. The experimental results are in good agreement with the calculated results. In order to control the temperature of the alloy melt, the relationship between the melt temperature and the melting power and charge quality of the ISM process was established by using the developed temperature field calculation program. The procedure was used to predict the change of shape and size of the crust in the ISM melting process. The process of the test was also studied. The calculated results are consistent with the experimental results.