Abrasive Jet Machining (AJM)
Abrasive jet machining is a process that removes material from a workpiece with the help of abrasive particles. The process consists of a mixture of fine abrasive particles and gas at high pressure. The abrasive particles strike the workpiece at high speed through a nozzle, impacting the workpiece surface which results in the removal of metal.
Components of AJM
Components include: Abrasive delivery system (Hopper), Mixing chamber, Vibrating device, Nozzle, Pressure gauge.
AJM Process Set-up
A typical set-up of AJM includes an abrasive jet in a filter system for abrasive erosion or velocity abrasive.
AJM Process Parameters
Parameters for successful utilization of AJM process:
- Material Removal Rate (MRR)
- Geometry of the Work-Piece
- Surface Finish of the Work-Piece
- Wear Rate of the Nozzle
Types of Abrasive Materials
Different types of abrasive are used in abrasive jet machining like garnet, aluminum oxide, olivine, silica sand, etc. Virtually any material can be cut by using abrasive jet machining method, from harder materials like titanium to steel.
Advantages
- Intricate cavities and holes of any shapes can be easily machined.
- No direct contact of tool and workpiece.
- Low capital cost.
- Less vibration.
- No heat generated in the workpiece. Environmentally friendly.
Disadvantages
- Low metal removal rate.
- Once used, abrasive particles cannot be reused.
- Relatively poor machining accuracy. Not suitable for machining of ductile material.
- Taper is also a problem.
Applications of AJM
- Used for fine drilling and micro welding.
- Manufacture of electronic components including fragile devices like germanium, silicon, etc.
- Machining of semiconductors.
- Machining of brittle materials like glass, ceramics, refractories.
