The surface treatment of weldments is generally done by polishing, which is relatively slow, and the labor cost is also high. There are some uneven surfaces, and polishing is actually very time-consuming and even not very clean. So what cleaning process is very suitable for the anti-rust treatment of the surface of the weldment? Laser derusting machine can be considered.
After the laser descaling machine irradiates the laser directly on the surface of the welded part, its laser will reflect the oxidation color of the surface, and then the surface oxidation color can be cleaned. In addition, the laser of the laser descaling machine is more unique, it is 1064nm Laser, this type of laser is not easy to damage metal materials, so if you want to make micro-roughness or non-damage cleaning, you only need to adjust the main parameters in the laser descaling machine. If the main parameters are adjusted correctly, cleaning The actual effect that comes out is what you need.
The Importance of Clean Surfaces for Welding
But if you patiently tell your engineers about professional cleaning knowledge before welding and complete detailed training, I believe that the aluminum products you deliver will exceed the expectations of customers. Because, under the requirements of refined manufacturing, the degree of cleanliness determines the degree of your welding task in a certain sense. Clean surfaces contribute to successful welding:
Consistency: Clean welding consumables provide a degree of consistency in the fabrication lab and allow you to use aluminum as a control variable for weld performance.
No porosity: Porosity is a defect in the surface quality of a metal caused by the welding of contaminants such as hydrocarbons or oxidation into the metal. If the metal becomes porous, it will form a poorly structured joint, which may even fail if the metal is sufficiently porous at the weld. But if the aluminum is clean, there will be no hidden defects in the weld and the joint should work as expected.
High Strength: Because of the absence of contaminants, welds made with pure aluminum have higher tensile strength than welds made with contaminated aluminum or aluminum containing alumina. Since metal welds bear responsibility for the overall safety and durability of the construction project after construction, the welds used must be as strong as possible to prevent accidental structural damage.
High Quality: If trained welders clean their aluminum, this leads to a high quality welding process, and high quality welding jobs are paid and rewarded more than poor quality welding jobs. High-quality welding work is also a must for someone who likes to take pride in their work, especially if they build it with their own hands.
Main Types of Aluminum Pollutants
From mass retail manufacturing of aluminum to welding workshops, aluminum is exposed to several main types of contaminants. These pollutants can be divided into three main categories:
1. Moisture: Since aluminum oxidizes extremely quickly, this means that it must be kept as far away from moisture as possible. Aluminum can be exposed to moisture both in transport conditions and in storage conditions upon arrival at the job site. This moisture can come from direct exposure, such as ambient moisture leaking into the air. Aluminum can also suffer from direct moisture damage due to condensation. This often occurs in storage areas where humidity is not controlled, as temperature fluctuations in storage can cause water to condense on aluminum surfaces.
2. Lubricants: Building materials are often coated with lubricants or other oils to increase their visual appeal and protect them from moisture damage. Unfortunately, if burned during welding, these lubricants and oils can release chemicals that can create defects in the weld. These lubricants can also cause oxidation by releasing hydrocarbons if left on aluminum for extended periods of time.
3. Oxides: Alumina is what forms when aluminum is exposed to moisture and oxides or rusts. This rust has a higher melting point than pure aluminum alloys, so welding jobs will be more difficult. Aluminum alloy has a melting point of 12000F, while aluminum oxide has a melting point of 37000F. As you can see, if aluminum is rusted before use, it is much more difficult to melt it down. Oxidation not only makes welding inherently more complex, but it also leads to multiple oxide inclusion type defects in the weld, degrading the overall work quality and making it more prone to structural failure.
While these are the main categories of pollutants to which aluminum may be exposed, other listed pollutants are not excluded:
- oil or grease
- ink
- grease
- particulate dirt
Many things can stain and contaminate aluminum prior to welding, and the presence of this contaminant can have serious long-lasting effects on weld quality. This is why it is so important to degrease and deoxidize aluminum prior to welding.
An efficient way to clean aluminum surfaces before welding
Manual cleaning is great, but time consuming. Forging companies all use manual removal of scale, and the degree of cleaning is not so clean, it is impossible to guarantee complete removal of scale. For many welders, finding alternatives is critical to reducing manual cleaning time. If your aluminum needs to be processed in batches, when faced with the difficult removal process, high temperature, and long time-consuming problems, you can choose laser cleaning, robotic cleaning systems, and electrochemical welding cleaners.
Laser cleaning to remove oxides
Laser cleaning, also known as laser oxide removal, removes all types of contamination in one go. When a laser beam hits an aluminum surface, grease, oil, dirt and aluminum oxide all evaporate into dust and fumes. The laser sends just the right amount of energy to remove these contaminants without introducing impurities into the aluminum. As shown in reports on welding laser cleaning, laser cleaning significantly reduces the number and size of pores in welded joints.
