Micro welding involves performing metal fusion at an incredibly small scale. This welding method is so small, that the welder has to use a microscope to see their process. Also known as precision welding, this specialized micro-operation requires accuracy and expertise, as the welding materials are typically delicate and complex. In micro-welding, a typical bead size can be as large as .065 and, depending on the scenario, be as small as .005.
The history of micro-welding goes back more than one hundred years. Ford company first tried the micro-welding technique. They used it to weld the metals within the vacuum tube with a high melting point. They had to resort to this technique, as standard soldering would not have survived high melt points.
On the other hand, micro resistance welding was also used in orthodontic instruments. However, orthodontic appliances could not use all metals because of human body internal use. Therefore, the micro resistance welding technique was used to join nonferrous metals.
Micro welding innovation became inevitable because of the welding needs of nonferrous metals like nickel, tungsten, and molybdenum. Hence the modernization came through, and emission type welding replaced old resistance welding.
The initial days’ story is interesting for tools and dies welding as well, as hydrogen gas and two tungsten electrodes were used in the process. It was merely a process of creating excess temperature on the steel to burn it for welding.
The electronic industry later realized the maximum benefit of micro-welding. This high-quality, complex micro-welding process still helps in joining small components of electronics with high precision.
Micro Welding equipment is also evolving with time. Machines used for micro welding were huge, but they are small and easy to carry. Torches used in welding have also seen innovation to create ease for the welder. These torches are smaller and easier to handle. The lenses available are welder friendly and help the handler to focus on defined weld areas.
Micro welding uses mini TIG apparatus, which is just like the size of a pen, and it demands focus and precision from the worker. Since the reference here is to weld minimal components, little heat is required to safeguard surrounding areas. Therefore, as per the defined process, a first evaluation of the product is done to determine temperature levels. Evaluation is to ensure that welding performance is not damaging the surface of the product. Modern-day micro-welding equipment is competent to examine weld parameters, mechanical or electrical, and internal resistance. This makes the equipment capable of adjusting factors to deliver consistent welds.
Micro-welding requires special equipment and machines due to the nature of its operation. The process has now even reached a stage of automation in different industrial setups.
There are many different types of welding that are in use on a large scale in the industry. Below are some different micro-welding techniques that are currently in use:
A high-temperature plasma creates an arc between a tungsten electrode and workpiece. In simple terms, heat generation through the formation of an arc performs the welding. This causes similar or different materials to melt and fuse. The material used for micro TIG welding includes pure tungsten, and other materials contain tungsten like thorium, cerium, lanthanum, yttrium.
As shared above, resistance micro welding is the method that initiated the micro-welding process. In the procedure of resistance micro-welding, the current is received from electrodes and the welder maintains the pressure. Resistance welding can perform spot welds with high precision and quality.
Micro laser welding as the name suggests is laser-driven. Laser welding is very common with automated welding units. Laser welding is known for precise processes and quality joints. Lasers help in piercing deep and provide quality fusion. The laser process does not produce any gas and hence avoids surrounding contamination.
Laser micro-welding joins high-value miniature components in industries like medical, electronics, automotive, telecom, etc. It is capable of joining both ferrous and non-ferrous parts of the metal piece.
Flash welding is known for producing clean joints using high pressure. It does not use any filler metals. Flash micro welding is a type of resistance welding. In the process of welding, the ends of the product are pressed together, so that current and preheat generate a specific temperature. When the heating is appropriate, the parts are pressed against each other firmly and slowly, causing the melt and fusion.
Micro-welding has evolved from the micro resistance process stage to a stage where laser technology is in use. Micro welding has opened a new path for engineers and welding technicians to weld all the immature materials required for any purpose they need and is evolving continuously. However, innovation so far is not enough and needs to go a long way from here. Becoming a qualified welder is now more exciting than ever with the advent and advancement of technology. New opportunities and immense scope for the growth for a career as a welder are present today. The earning for a certified welding technician is great and higher than the average salary of other skilled trades in the industry. Getting a certification from one of the top welding trade schools in the USA can open up various career opportunities in the industry and all over the world. Welders are in high demand due to the nature of their work and it is certain that getting a welding education is highly lucrative.