Abstract

In order to develop a scientifically grounded technology for production of porous getters, there appears the necessity to apply highly sensitive methods for determining the activation temperature, which are compatible with the standard magnetron pumping technology. In this study, a complex technique for determining the activation temperature for porous getters is proposed using the experimental scheme simulating the conditions of porous getter activation in accordance with the standard exhaust tube pumping technology. Under the conditions of the simulation of physicochemical processes in the volume of the heated magnetron housing under pumping, the model of the formation of a gas load on the interior pumping equipment is considered. It is shown that, according to the theory of composite chemical reactions, thermal desorption flows are generated by either the theory of consecutive reactions or the theory of parallel-consecutive reactions. The sorption capacity of porous getters is determined from a plot as the time–temperature dependence of the mass yield of composite chemical reactions of interaction between the gas load and the surface and bulk of a getter tablet. A getter tablet’s change in mass is recorded using the microbalance of a vacuum thermogravimetric unit uninterruptedly at the frequency of one measurement a second throughout the entire period of measurements. The sensitivity threshold of the microbalance is 10^–5 g and the maximum mass is 5 g. Using the theory of parallel-consecutive reactions, for the first time, the minimum temperature of thermal activation of a porous getter of a Ti–V (30 at %) alloy is determined, which is the main technological parameter when interior pumping equipment is employed. For the nonisothermal part of the standard heat treatment plot, at the heating rate of 10°C/min and the specified vacuum conditions, the minimum activation temperature is 393°C. For estimating the changes in the roughness of the free surface of a getter washer subjected to interior saturation in a hydrogen medium, scanning electron microscopy is used. Cracks and microsized tetragonal single crystals are found, which might be titanium hydrides TiН₂. It is established that crack formation has a positive effect on the getter’s sorption activity due to the appearance of new atomically clean surfaces. However, cracking can contribute to the crumbling of the getter tablet. Therefore, the hydrogen gas load is the factor that limits the durability of the getter.

中文翻译：

---

磁控管生产技术中吸气剂的热活化

摘要

为了开发用于多孔吸气剂生产的科学基础技术，似乎有必要采用与标准磁控管抽运技术兼容的高度敏感的方法来确定活化温度。在这项研究中，根据标准排气管抽气技术，通过模拟多孔吸气剂活化条件的实验方案，提出了一种确定多孔吸气剂活化温度的复杂技术。在模拟在抽气下加热的磁控管壳体的体积中的物理化学过程的条件下，考虑在内部抽气设备上形成气体负载的模型。结果表明，根据复合化学反应理论，通过连续反应理论或平行连续反应理论产生热解吸流。多孔吸气剂的吸附能力是由一个图确定的，该图是气体负载与吸气剂片剂的表面和体积之间相互作用的复合化学反应的质量产率随时间和温度的关系。在整个测量过程中，使用真空热重分析仪的微量天平以每秒一次的测量频率不间断地记录吸气片的质量变化。微量天平的灵敏度阈值为10 多孔吸气剂的吸附能力是由一个图确定的，该图是气体负载与吸气剂片剂的表面和体积之间相互作用的复合化学反应的质量产率随时间和温度的关系。在整个测量过程中，使用真空热重分析仪的微量天平以每秒一次的测量频率不间断地记录吸气片的质量变化。微量天平的灵敏度阈值为10 多孔吸气剂的吸附能力是由一个图确定的，该图是气体负载与吸气剂片剂的表面和体积之间相互作用的复合化学反应的质量产率随时间和温度的关系。在整个测量过程中，使用真空热重分析仪的微量天平以每秒一次的测量频率不间断地记录吸气片的质量变化。微量天平的灵敏度阈值为10^–5 g，最大质量为5 g。利用平行连续反应理论，首次确定了Ti-V（30 at％）合金多孔吸气剂的热活化最低温度，这是使用内部抽水设备时的主要技术参数。对于标准热处理区的非等温部分，在10°C / min的加热速率和指定的真空条件下，最低活化温度为393°C。为了估计在氢介质中经受内部饱和的吸气垫圈的自由表面的粗糙度变化，使用扫描电子显微镜。裂缝和microsized四方单晶被发现，这可能是钛氢化物TiН ₂。已经确定，由于新的原子清洁表面的出现，裂纹的形成对吸气剂的吸附活性具有积极影响。但是，开裂会导致吸气片的破裂。因此，氢气负荷是限制吸气剂耐久性的因素。