A titanium getter in vacuum heat treating is a reactive material used to enhance the vacuum by removing unwanted gas contaminants. This is achieved through adsorption, absorption, or chemical binding with the gas molecules. Titanium, along with other metals like stainless steel, zirconium, and hafniRead more
A titanium getter in vacuum heat treating is a reactive material used to enhance the vacuum by removing unwanted gas contaminants. This is achieved through adsorption, absorption, or chemical binding with the gas molecules. Titanium, along with other metals like stainless steel, zirconium, and hafnium, are commonly used as getter materials due to their properties which are suitable for heat-treating applications.
In practice, titanium getters are particularly effective when processing titanium parts. To prevent oxidation and discoloration during annealing processes within a temperature range of 650°C to 760°C, titanium scraps are often included with the parts in the vacuum. This method ensures that the parts’ surfaces remain clean.
Furthermore, non-evaporable getters, which often include alloys from Group IV and V elements, are integral to creating ultra-high vacuum environments. These materials have unique surface properties that enable achieving vacuum conditions of 10-10 mbar or lower. They are used in various ways depending on the application, including in electronic tubes and semiconductor manufacturing.
Source: VAC AERO International – Getter Materials
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Non-evaporative getters (NEG) in vacuum heat treating are materials used to maintain or improve the vacuum quality by absorbing gas molecules without evaporating or changing their state. Unlike traditional getters that work by evaporating a material which reacts with and traps gas molecules, NEGs abRead more
Non-evaporative getters (NEG) in vacuum heat treating are materials used to maintain or improve the vacuum quality by absorbing gas molecules without evaporating or changing their state. Unlike traditional getters that work by evaporating a material which reacts with and traps gas molecules, NEGs absorb gases through a different mechanism.
Here’s a breakdown of how they work and their benefits:
Absorption Mechanism: NEGs typically consist of materials like zirconium, vanadium, and iron. These materials can absorb gases like hydrogen, nitrogen, oxygen, carbon monoxide, and water vapor at the molecular level. The process usually involves chemical reactions where gas molecules are chemically bonded to the getter material.
Activation Process: NEGs often require an activation process to start working efficiently. This process usually involves heating the getter to a specific temperature, which allows it to react with the gases more effectively.
Long-term Stability: One of the key advantages of NEGs is their long-term stability and efficiency. Unlike evaporative getters that lose their effectiveness over time as the getter material is depleted, NEGs can maintain their gas-absorbing properties for a longer duration.
Cleanliness and Safety: Since NEGs do not evaporate or release any material into the vacuum, they are considered cleaner and safer compared to traditional getters. This is particularly important in processes where contamination needs to be minimized.
Applications: NEGs are widely used in various high-vacuum applications, including semiconductor manufacturing, vacuum tubes, particle accelerators, and vacuum furnaces used in heat treating processes. They are essential in environments where maintaining a high-quality vacuum is crucial for the process’s success.
Limitations: While NEGs offer several advantages, they also have limitations. For instance, they have specific activation conditions and temperature ranges within which they operate effectively. Additionally, once saturated with gas, they need to be reactivated or replaced.
In vacuum heat treating, NEGs play a crucial role in ensuring that the vacuum remains free of unwanted gases, which can otherwise impact the quality of the heat treatment process.
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