Conventional and wide spread machining processes include: mechanical cutting operations, material removal techniques – chipping off, forging, casting, stamping, engraving. Additionally, conventional processes include turning, milling, drilling, grinding etc. mechanical operations. Back in the 1940s the needs of the defense industry, aviation and space industry, electronics and other industries necessitated machining techniques to be adopted for processing thin, fragile or special and very thin products that could not be manufactured using the conventional processes or this would have been rather impractical and costly. Therefore, a new group of “non-conventional” manufacturing processes emerged to provide improved, convenient and economically advantageous means for specific types of production. These were based on latest scientific and technical achievements and some new findings for using laws of nature relating to light – lasers, sound – ultrasonic processes, magnetism, atomic physics – plasma, electronics and new “powder” metallurgy materials.
Non-conventional processes include:
- Chemical machining (CM)
- Electrochemical machining (ECM)
- Electrochemical grinding (ECG)
- Electrical discharge machining (EDM)
- Wire electrical discharge machining (WEDM)
- Laser-beam machining (LBM)
- Electron-beam machining (EBM)
- Water-jet machining (WJM)
- Abrasive water-jet machining (AWJM)
- Abrasive-jet machining (AJM) (using air, sand or beads)
Additionally, we could include here Ultrasonic machining (UM) and Deburring processes.
Example: A typical non-conventional process is the machining of abrasive discs using diamond (adopted in 1955) or synthetic tools – cubic boron carbide (1970). In some applications these processes replaced almost completely the aluminium oxide processes (1893) and the green silicon carbide processes (1891). Other non-conventional processes include powder metallurgy processes used to produce hard-alloy cutting tools made of tungsten carbide, titanium carbide, cobalt carbide, etc.