Welcome to WeldingMachines.org. I am a Mechanical Engineer by education and work in the IT Industry. I could not get a good job in the Core industry to massive outsourcing, but my passion for Mechanical Engineering never waned, and I run several Hobby websites to keep me sane.
A brief History of Welding:
The history of welding goes back to several of millennia, the earliest being the bronze and iron ages in Middle East and Europe. One of the remarkable examples where welding was used was the construction of the iron pillar in Delhi, India at around 310 AD. But the major breakthrough in the field of welding took place in the 19th century when Sir Humphry Davy discovered the electric arc. And since then, there has been no looking back with many other popular types of welding like carbon arc welding, alternating current welding etc. have been discovered in the subsequent years of the 19th century.
Now let us talk about the device which actually carries out the process of welding. It is known as the Welding Machine.
Welding machines are devices that are used for bonding or joining metallic surfaces or alloys together with or without the use of weld alloys. The basic principle of welding is to apply heat to the metallic surface and then allow them to fuse to form a permanent bond.
With improvement in the field of science and technology, these days even plastic and ceramic surfaces can be welded.
Now the welding machines can be broadly classified as:
Constant Current: Output voltage is varied to maintain a steady current. For example, Shielded metal arc welding
Constant Voltage: Output current fluctuates to maintain a set voltage. For example, Flux core arc welding, Gas metal arc welding
These are also available in different types of designs. Let us look at some of these designs.
Generator and Alternator:
• Use generators and alternators for the conversion of mechanical energy to electrical energy.
• Use internal combustion engines or electric motors to drive the generator or alternator.
• Step down effect similar to Transformers.
• Produce DC from AC without the use of rectifiers.
• Converts the Low current and High Voltage electricity to High Current and Low voltage. Range of voltage and current typically lies between 17 to 44 volts and 55 to 990 Amperes respectively.
• Least expensive
• Inverter welding units are switching power supplies capable of handling very high loads or arc welding.
• Covert utility power into very high voltages and store it in a capacitor bank. Then to produce the desired welding current, a microprocessor controller switches this energy in another transformer. Switching frequency is of the order of 10,000 Hz or even more and these high frequency welding machines are more efficient than the other non-inverter welding machines.
Also depending upon the type of source of energy used for the welding process, welding machines can be further classified into the following types:
Arc welding machines: Uses welding power supply to create an arc between base material and the electrode. Here, very intense amount of heat is required to melt the metal and it is achieved through an electric arc. There are different types of Arc Welding machines available in the market. For example, Carbon arc welding machines (oldest welding technique and used in metalworking and water jet cutting), Gas metal welding machines (used in processes known as MIG welding processes and used in ship building, aerospace application etc.), Plasma arc welding machines(used when lower current ranges are required and used in dairy and food industry) etc.
Fusion Welding machines: Used for Fusion welding processes. Here a fusion or a heat source is required to do the welding. For example, Electron Beam welding machines (uses a beam of high velocity electrons and used in nuclear fields, power stations etc.), Hot plate welding machines (used for welding mass produced injection moulding and is applied in building and automotive word), Laser welding machines (to create selective area spot welds and is used in electronic industry, plastic industry etc.) etc.
Resistance Welding machines: Used for resistance welding processes. In this process mechanical pressure and electric current is applied to create a weld. For example, Spot welding machines (employs application of heat and pressure and is used in casting and fabrication), Flash welding machines (creates fusion between two surfaces by application of heat and pressure and is used in aerospace and automobile industry), Projection welding machine (used for welding steel wired, shopping carts etc.) etc.
Solid State Welding machines: Used for Solid state welding processes. Such processes are employed when the fusion of materials to be welded is required at temperatures much below the melting point of the base material and also without the use of filler material. For example, cold welding machine (welding under high pressure or vacuum and without the application of heat and used in nuclear reactors and powder metallurgy), Diffusion welding machine (used in joining refractory metals), Ultrasonic welding machine (high frequency ultrasonic acoustic vibrations are used and finds application in automotives and packaging) etc.
Other Types: These include welding machines which are required in processes other than those mentioned above. For example, Induction welding machine (uses electromagnetic induction to heat the base metal), Thyristorised welding machines (suited best for manual metal arc welding).
Some of the big guns which are involved in the production of these welding machines include Siemens, Panasonic, Shen Zhen Grand M&E Equipment Limited Company etc.
Now if we look at the applications of these welding machines, they are just hard to imagine. They are used in automotive industry, medical equipments electronic industry, battery fabrication, ships, furniture, computers, aircrafts etc. Today almost everything is welded!
These days welding is even emerging out as a very good career option. It is seen something which blends art with science. It requires precise skills like mechanical ability, imagination, patience, Problem solving sharp mind etc. Also the job portfolios available in welding industry are numerous like Material engineer, Welding engineer, electrical engineering, welding technician, business owners, engineering mechanics and many more!