Laser Cutting

Laser cutting is a type of cutting where machines can accurately produce complex exterior contours.  Laser cutting takes direct input in the form of electronic data from a CAD drawing to produce flat form parts that are very complex.  The laser beam used is typically 0.2 mm diameter at the cutting surface with a power of 1000 to 2000 watts.  The best materials to use lasers on are carbon steel and stainless steels.  Copper alloys and aluminum are tough to use lasers on because they reflect the light well and absorb and conduct heat well. 

Plasma Cutting

Plasma cutting is a process that uses a high velocity jet of ionized gas that is delivered from a constricting opening.  The most common gases are nitrogen, oxygen and argon.  Plasma, conducts electricity from the torch of the plasma cutter to the work piece. The plasma then heats the workpiece, melting the material. The high velocity stream of ionized gas mechanically blows the molten metal away, severing the material.  Plasma cutting is generally used for non-ferrous materials. 

Oxy-Fuel Cutting

The oxy-fuel process is also called oxyacetylene welding.
The reason for this is because acetylene is the main choice of fuel.  It is the most widely applied industrial thermal cutting process for many reasons.  It can cut thicknesses from .25 inch to 10 inches, the equipment is low cost and it can be used manually or mechanized.  A blowtorch is used until the metal glows.  Then a lever on the torch is pressed to blow oxygen into the gas mixture.  That is used to blow and melt the metal with the extra heat. 

Abrasive Water-Jet Cutting

Abrasive water-jet cutting is a ‘cold’ metal cutting technique that combines a high pressure (4,000 bar) ‘beam’ of water with abrasive particles that cuts through material. The abrasive particles are typically garnet. The resultant finish is similar to sandblasting and leaves no burr or heat affected zone (HAZ).

The accuracy of Water-jet cutting is not as good as wire EDM typically ± 0.0015 in. but is up to 10 times faster. Both conductive (metals) and nonconductive (plastics and ceramics) can be cut with water-jet technique. The limitations for water-jet are the maximum thickness of cut. Cutting of thicker work pieces is detrimental to accuracy. Typically water-jet cutting is used for materials 4” and less.

Wire EDM (Electrical Discharge Machining)

Wire EDM is a metal cutting process which utilizes spark erosion to remove metal from the work piece. DC electric pulses are passed through a negatively charged wire. As the wire does comes into close proximity with the positively charged work piece a spark is formed which erodes the work piece. The wire and the work piece are always separated by a dielectric fluid. The molten metal and kerf are washed away by the dielectric solution used to promote the spark.