Metal workpieces often undergo a wide array of heat treatment processes to attain notable changes to their properties. Most of the time, these processes alter their structural and physical properties for them to be useful for subsequent manufacturing processes.
Heat treatment processes typically involve heating or chilling the workpieces to extreme temperatures. Some notable techniques that can be maximised by manufacturers during heat treatment include annealing, case hardening, tempering, carburising, precipitation strengthening, and quenching. Another process that can be utilised in altering metal workpieces is vacuum heat treatment.
The Working Principles of Vacuum Heat Treatment
Vacuum heat treatment is a method wherein metals are hardened at extremely high temperatures. It is conducted in a vacuum that possesses an absolute pressure below the normal atmosphere and does not have any air. The characteristics of the vacuum enable it to generate an unreactive environment, which can be perfect for processing metal workpieces.
Heat, after all, can provide reactions to the metal once it interacts with the air. Without the vacuum chamber, the metal workpieces may develop surfaces that are harder or softer than the expected outcome. The oxidation process, therefore, is prevented with vacuum heat treatment.
When conducting vacuum heat treatment, the vacuum chamber maximises a vacuum pumping system that can remove the air. Once the air is removed, the metal workpiece inside the chamber is then heated up to 1,316 degrees Celsius at a controlled rate before lowering the temperature. The soak time of this process typically depends on the requirements of the part and its material.
Vacuum Heat Treatment’s Noteworthy Advantages
There are a couple of advantages that one can obtain from vacuum heat treatment.
One of the advantages of vacuum heat treatment is that it eliminates the need for oxidation and decarbonisation. Oxidation and decarburisation can easily affect the quality of the workpieces negatively. But since the air is removed from the vacuum chamber, the metal workpieces can effectively retain their lustre and mechanical properties despite undergoing heat treatment.
Another advantage of vacuum heat treatment is it eradicates additional cleaning processes. Metal workpieces that undergo vacuum heat treatment do not have to be cleaned just to make their surface aesthetically appealing. This benefit helps manufacturers conserve time and money.
The mechanical properties of the metal workpieces are likewise preserved with vacuum heat treatment. Aside from removing the air, vacuum heat treatment can also help decrease hydrogen levels inside the chamber, preventing the workpieces from getting brittle. Once the heat treatment process is done, the metal workpieces are expected to gain ductility, fatigue, and toughness benefits. They can even attain improved lifespan and enhanced functionality.
Principal Applications of Vacuum Heat Treatment
Vacuum heat treatment can be very effective in processing workpieces made from metal-based super alloys like iron-nickel or cobalt-nickel. It can likewise be utilised in processing reactive and refractory materials such as titanium and stainless steel.
Some industries that can take advantage of this process is aerospace, aircraft, and automotive.
To learn more about vacuum heat treatment, you can call us at Alpha Detroit Heat Treatment.