Welding various metals together usually calls for specialized knowledge and abilities. Even the hardest-to-weld materials can be joined with the correct welding technique applied by a qualified welding provider. Laser welding is one such technique that can efficiently join dissimilar metals.
With its fast welding speed and precision, laser welding has the ability to mitigate the challenges that come with welding dissimilar metals. That means, as you are working for a precise and accurate final outcome, you should be aware of the challenges and how laser welding works.
So, in this article, we will give you a better picture of laser welding dissimilar metals. We will share the challenges and key considerations associated with the welding process. We will also tell you about the different laser welding methods that can be used to weld non-similar metals. So keep on reading to take your welding skills to a greater height.
What Is Dissimilar Metal Welding?
“Dissimilar metal welding” is the process of joining metals that are very different from each other in terms of the alloys they are made of. The welding process involves melting and mixing the parent material with the welding material.
Welding dissimilar metals requires varying degrees of expertise based on the metals and welding process being used. Only a skilled welder who knows a lot about welding techniques and the metals they are joining should be able to join metals that are not the same.
Challenges in Joining Dissimilar Metals
Problems like cracking, porosity, and warping could make welding different metals difficult. Here are the challenges that a welder might face during the process:
- The expansion and contraction rates of metals, in addition to their melting points, can cause porosity. Varying metals’ expansion and contraction rates can also cause warping.
- When metals that are not the same are joined, too much dilution can cause hot cracking. This is also called solidification cracking.
- It is possible for corrosion to form at the intermetallic zone (where the metals change from one to the other) or on the overlay surface itself when different metals are welded together. Corrosion is also likely to appear when metals with very different electrical and chemical properties are diluted.
- When metals are heated, they expand and change shape. If the two metals change shape at different rates or degrees, strain during the welding process can result in thermal cracking.
Key Factors for Dissimilar Metal Welding Operations
As there are inherent difficulties in welding dissimilar metals, some factors must be considered in order to achieve optimal results. Let’s look at them:
- At the time of welding, metals that are not the same must be mixed in a solid way so that stable metallurgical phases are formed. These may consist of one or more stages. The degree of dilution establishes the phase.
- Measuring weldability is necessary prior to welding. It checks how well two metals can be joined together without cracking.
- There are various temperatures at which metals can melt. Thus, welders must employ a method of preheating the metals to their melting points or devise a method that does not necessitate melting any of the metals.
Benefits of Laser Welding Dissimilar Metals
Welding dissimilar metals is a difficult task due to the need to balance key factors and manage challenges. Thankfully, laser welding makes the process seem rather easy. It minimizes many of those challenges. Let’s look at all the advantages laser welding brings to the table while welding dissimilar metals:
- Laser welding creates complicated joints that make sure that different alloy parts work well together.
- Focusing laser beams on the weld point greatly lowers the amount of heat needed and protects metals with different melting points.
- Because the laser beam is so narrow, it limits the heat-affected zone. This keeps the material around it from being affected and stops intermetallic compounds from forming.
- Laser welding improves productivity by allowing faster welding speeds. As heating and cooling cycles occur quickly in this process, it takes less time to reach the critical temperature ranges.
- Different kinds of materials, including ones with different chemical and physical properties, can be welded with a laser. (e.g., aluminum/titanium, aluminum/copper, etc.)
- Laser welding guarantees clean metal surfaces owing to its precise control and non-contact nature.
- The welds made by laser welding are flawless, guaranteeing consistency and dependability.
- Many environments, like inert gas atmospheres or vacuums, can be used for laser welding. This makes it good for metals that are environment-sensitive.
- It is possible to automate laser welding. This is good for industries that need to produce items or components quickly and consistently.
- Laser welding keeps joints strong because it is very precise and uses little heat. This means that there is no need for a lot of processing after the welding is done.
Methods of Laser Welding Dissimilar Metals
There are a number of variations on laser welding that can join chemically different metals. The application primarily determines the use of all of these methods. Let’s have a look at these methods:
Fiber Laser Welding
This kind of laser welding uses a fiber laser beam. This high-quality beam can be used on dissimilar metals. Extreme precision makes it very popular in the aerospace and auto industries.
Keyhole Mode Laser Welding
High-power density welding, like keyhole mode laser welding, can be used on thicker materials. Materials that need to go through a deep hole are laser-welded in this way. The molten material is then poured into the keyhole to make a very strong weld.
Laser Brazing
The basic method of laser brazing involves melting filler materials. This is usually done with metals that do not melt easily. It makes the joints strong without changing their shape.
Laser Cladding
Laser cladding is a technique that uses a laser beam to incorporate a substrate layer onto a metal surface. This allows for the cladding of non-similar metals, which in turn imparts valuable properties such as resistance to corrosion.
Conduction Mode Laser Welding
With conduction mode laser welding, a laser beam is used to join two thin materials together. In this instance, a metal acts as a heat conductor, melting the interface between the two non-similar metals.
Hybrid Laser Welding
A hybrid laser welding process combines gas tungsten arc welding with metal inter-gas welding. Different metals are welded together using this laser welding method to find the right balance between heat input and penetration. This method gives the welder more control over the heating process.
Continuous Wave Laser Welding
A laser beam is constantly put on the joint during continuous wave laser welding. It makes a good weld because it has a high welding speed and can join thin pieces of different metals.
Pulsed Laser Welding
You can precisely control the short bursts of laser energy used in pulsed laser welding. Mixing different alloys is possible with controlled heat. Besides, joining metals with different melting points also becomes simple.
Conclusion
Joining different alloys with dissimilar metal welding is tricky because of problems like cracking and warping. That’s why managing things like corrosion, thermal stresses, and expansion rates is important. Laser welding addresses these issues with precision and minimal heat input. It creates strong, defect-free welds, limits heat-affected zones, and allows high productivity.
Besides, laser welding works with many materials and settings can be automated. The process also requires less work to be done after the welding. Different methods of welding exist that can join dissimilar metals brilliantly. These methods include fiber laser welding, laser brazing, cladding, etc.
Among these methods, fiber laser welding holds a special place due to the precision it brings. However, without a high-quality machine, such precision is nothing but a dream. That’s why we at Fiber Laser Welder commit ourselves to give our customers only the best fiber laser welding machines. Offering the best quality, service, and value, we are here to build long-lasting relationships. Join forces with us, and we can reimagine manufacturing’s future.
