Most machinists are familiar with the four processing methods, but did you know the concrete differences between them? When the correct selection of them is done, A fast and highly accurate operation for your project will advantageously conduce to your productivity and precision of work.  

Laser cutting

Laser cutting is to use a focused high power density laser beam to irradiate the workpiece so that the irradiated material can melt, vaporize, ablate or reach the ignition point rapidly. At the same time, the melted material can be blown away by high-speed airflow in the coaxial direction of the laser beam, so that the workpiece can be cut off. At present, the CO2 pulse laser is commonly used. Laser cutting is one of the hot cutting methods.

Water Cutting Processing

Water cutting, also known as water knife, is a high-pressure water jet cutting technology, is high-pressure water cutting machine. Under the control of the computer, the workpiece can be carved arbitrarily, and it is less affected by the material quality. Water cutting can be divided into sand-free cutting and sand-adding cutting.

 

Plasma cutting

Plasma arc cutting is a kind of processing method which uses the heat of high-temperature plasma arc to melt (and evaporate) the metal at the cutting edge of the workpiece and removes the molten metal by the momentum of high-speed plasma to form the cutting edge.

 

WEDM

Wire Electrical Discharge Machining (WEDM) belongs to the field of electrical processing. Wire cut Electrical Discharge Machining (WEDM) is sometimes called WEDM. WEDM can be divided into fast WEDM, medium WEDM, and slow WEDM. The wire traveling speed of fast wire EDM is 6-12 m/s, and the wire travels at high speed, so the cutting accuracy is poor. Mid-wire WEDM is a new technology developed in recent years, which realizes the function of frequency conversion multiple cutting on the basis of fast-wire WEDM. The wire traveling speed of WEDM with slow walking wire is 0.2m/s, and the electrode wire moves unidirectionally at low speed, so the cutting precision is very high.

The contrast of application scope

Laser cutting machine has a wide range of applications, regardless of metal, non-metal, can be cut, cutting non-metal, such as cloth, leather, etc. can be used CO2 laser cutting machine, cutting metal can be used optical fiber laser cutting machine. The deformation of sheet metal is small.

Water cutting belongs to cold cutting, no thermal deformation, good cutting surface quality, without secondary processing, if necessary, it is also easy to carry out secondary processing. Water cutting can punch and cut any material with fast cutting speed and flexible processing size.

The plasma cutting machine can be used to cut stainless steel, aluminum, copper, cast iron, carbon steel, and other metal materials. The plasma cutting has an obvious thermal effect and low precision, so the cutting surface is not easy to be processed again.

WEDM can only cut conductive substances. Cutting process requires cutting coolant, so it is impossible to cut materials that are not conducive to paper, leather, water, and pollution of cutting coolant.

Cutting thickness comparison

The application of laser cutting carbon steel in the industry is generally below 20MM. Cutting capacity is generally less than 40MM. Stainless steel industry applications are generally below 16MM, cutting capacity is generally below 25MM. And with the increase of workpiece thickness, the cutting speed decreases obviously.

The thickness of water cutting can be very thick, 0.8-100MM, or even thicker material.

The plasma cutting thickness is 0-120 mm, and the best cutting quality range thickness is about 20 mm. The price ratio of plasma system is the highest.

Wire-cut thickness is generally 40-60 mm, the thickest can be up to 600 mm.

Cutting speed comparison

The cutting speed of 2 mm thick low carbon steel plate and 5 mm thick polypropylene resin plate can reach 600 cm/min and 1200 cm/min respectively. The cutting efficiency of WEDM is generally 20-60 square millimeters per minute, and the maximum is 300 square millimeters per minute. Obviously, the laser cutting speed is fast and can be used in mass production.

Water cutting speed is quite slow, not suitable for mass production.

The cutting speed of plasma cutting is slow and the relative precision is low. It is more suitable for cutting thick plates, but the end face has a slope.

For metal processing, WEDM has higher accuracy, but the speed is very slow. Sometimes it needs other methods to cut through holes and wires, and the cutting size is limited.

Comparison of Cutting Accuracy

Laser cutting has a narrow cutting edge, parallel cutting edges, and perpendicular to the surface. The dimension accuracy of the cutting parts can reach (+0.2mm).

The plasma energy is less than 1 mm.

Water cutting will not produce thermal deformation, the accuracy is (+0.1mm). If the dynamic water cutting machine is used, the cutting accuracy can be increased to (+0.02mm) and the cutting slope can be eliminated.

The machining accuracy of WEDM is generally (+) 0.01 (+) 0.02 mm) with a maximum of (+) 0.004 mm.

The contrast of slit width

Laser cutting is more precise than plasma cutting, with a small slit, about 0.5 mm.

The plasma cutting slit is larger than laser cutting, about 1-2 mm.

The cutting seam of water cutting is about 10% larger than the diameter of the cutter tube, which is generally 0.8mm-1.2mm. With the diameter enlargement of the sand cutter tube, the larger the incision is.

The slit width of WEDM is the smallest, generally about 0.1-0.2 mm.

The contrast of Cutting Surface Quality

The surface roughness of laser cutting is not as good as that of water cutting. The thicker the material, the more obvious it is.

Water cutting will not change the texture of the material around the cutting seam (laser is thermal cutting, it will change the texture around the cutting area).

The contrast of Production Input Cost

Laser cutting machines for different purposes have different prices. Cheap ones such as carbon dioxide laser cutting machines only need 230,000 yuan, and expensive ones such as 1000W fiber laser cutting machines now need more than 1 million yuan. Laser cutting has no consumables, but the cost of equipment investment is the highest in all cutting methods and is not a little higher, the use and maintenance costs are also quite high.

The plasma cutting machine is much cheaper than the laser cutting machine. According to the power and brand of the plasma cutting machine, the price is different and the cost is high. Basically, as long as the conductive material can be cut.

The cost of water cutting equipment is second only to laser cutting, which has high energy consumption, high maintenance cost and no plasma cutting speed. Because all abrasives are disposable, they are discharged into nature once, so environmental pollution is serious.

WEDM is usually about tens of thousands of pieces. But WEDM has consumables, molybdenum wire, cutting coolant, etc. There are two kinds of wire commonly used in WEDM. One is a molybdenum wire, which is used in fast wire-moving equipment. The advantage is that molybdenum wire can be reused many times. The disadvantage is that it is expensive. The other is to use copper wire for slow-moving wire equipment. The advantage is cheap, but the disadvantage is that copper wire can only be used once. In addition, the fast wire walking machine is much cheaper than the slow wire walking machine. The price of one slow wire walking machine is equal to 5 or 6 fast wire walking machines.