In this post, you learn what is Ion beam machining. And its diagram, parts, working, advantages, and disadvantages.
What is Ion-Beam Machining (IBM)?
IBM or etching is generally a surface finishing process in which the material removal takes place by sputtering of ions.
The process is different from electric discharge, electron beam, laser, and plasma arc machining in that the process does not depend on the heating of the workpiece to the point of evaporation.
This sputter etching mechanism is very simple. It consists of bombarding the work with accelerated ions which collide with the surface atoms of the work.
Each bombarding ion, as a result of collisions, dislodges surface atoms by transferring kinetic energy from itself to the atoms of the surface layer.
It consists of an electron gun that discharges free electrons into a chamber filled with argon gas. The gas is then ionized by the electrons. The top of the chamber is called an ion-beam generating apparatus.
At the other end, the workpiece is fixed to a table which can be oscillated and rotated so that different points on the work surface can be subjected to ion-beam.
Working of IBM
Ion beam machining (IBM) is an atomic-bit machining technology that produces products with a high resolution of around 0.1 μm.
Ions of inert gases, such as argon, with a high kinematic energy of around 10 KeV are employed to strike and eject atoms off the workpiece surface by elastic impact.
Unlike machine tool processes like cutting, grinding, and lapping, IBM has an essential reference surface; instead, a patterned mask serves as the reference.
IBM could be utilized for micromachining along with a high-precision position control machine tool and a micro-ion beam with a diameter of 1-2 μm.
IBM is also used for aphorizing lenses, etching IC patterns, honing diamond microtone knives and cutting tools, and other tasks. Because IBM machines are so expensive, the process becomes unprofitable due to increased machining costs.
Ion Beam Machining Accuracy
Practical etching rates vary up to 2000 A (2 x 10-4 mm) per min. The accuracy of the etching process is considerably high mainly due to the small amount of material removal. Tolerances in the vicinity of + 50 Å (+ 5 x 10-mm) are possible.
Applications of Ion-Beam Machining
It is applied mostly in micro-machining (etching) of electronic components like computer parts, figuring optical surfaces, and for the precision fabrication of fine wire dies in refractory materials.
Typical materials that can be etched include glass, alumina, quartz, crystals, silica, agates, porcelain, and cermets. and numerous metals and oxides.
Advantages
Ion-beam machining has many advantages which include:
- The process is almost universal.
- No chemical reagents or etching compounds are required.
- There is no undercutting as with another chemical etching process.
- Etching rates are easily controlled.
Disadvantages
This process has many disadvantages, which are as follows:
- It is relatively expensive.
- Etching rates are slow.
- Although virtually no heat is generated there is little possibility of some thermal or radiation damage.