Laser welding is a fast, precise, and versatile technique that can be used for various applications in different industries. But which materials can you weld with a laser? In this article, we will answer this question and explain the factors that affect the weldability of different materials.
I. The main factors that determine the weldability of a material are:
The optical properties of the material, such as its reflectivity, transmission, and absorption of the laser beam. The material should have a high absorption rate and a low reflectivity and transmission rate to ensure efficient and stable welding
The thermal properties of the material, such as its melting point, thermal conductivity, thermal expansion, and specific heat. The material should have a low melting point, high thermal conductivity, low thermal expansion, and high specific heat to reduce the heat-affected zone (HAZ) and minimize distortion and cracking
The chemical properties of the material, such as its composition, purity, and compatibility with other materials. The material should have a homogeneous and consistent composition, high purity, and low susceptibility to oxidation and contamination. It should also be compatible with the shielding gas and the filler metal (if used) to avoid adverse reactions and defects
II. Based on these factors, some materials are more suitable for laser welding than others. Here are some examples of common materials that can be laser welded:
Metals: Metals are generally good absorbers of laser energy and have high strength and conductivity.
Examples: aluminum, copper, brass, steel, titanium, and nickel. The process can be used to join pieces of significantly divergent thicknesses, increasing its applications to a wider selection of tasks than traditional thermal or electrical welding methods
Plastics: Plastics are thermoplastics that can be melted and reshaped by heat.
Examples: polycarbonate, nylon, and ABS. The process can be used to weld transparent or opaque plastics with or without additives or fillers. The main challenge is to match the optical and thermal properties of the plastics to ensure a strong bond
Ceramics: Ceramics are non-metallic materials that have high melting points and low thermal conductivity.
Examples: alumina, zirconia, and silicon carbide. The process can be used to weld ceramics with or without preheating or filler metal. The main challenge is to avoid cracking due to thermal stress and mismatched coefficients of thermal expansion
Composites: Composites are materials that consist of two or more different components that have different properties.
Examples: carbon fiber-reinforced plastics (CFRP), glass fiber-reinforced plastics (GFRP), and metal matrix composites (MMC). The process can be used to weld composites with similar or dissimilar components. The main challenge is to avoid damage to the reinforcement fibers or matrix material due to excessive heat or mechanical stress.
Laser welding can also weld refractory materials or dissimilar materials with good results. Refractory materials are those that have high melting points or resist deformation under heat, such as titanium or quartz. Dissimilar materials are those that have different physical or chemical properties, such as steel and aluminum. The main challenge is to optimize the process parameters and select the appropriate laser source, shielding gas, filler metal, and joint design to achieve a satisfactory weld quality.
III. Conclusion
Laser welding is a process that can weld various materials with different properties and thicknesses. The weldability of a material depends on its optical, thermal, and chemical properties. Some common materials that can be laser-welded are metals, plastics, ceramics, and composites. Laser welding can also weld refractory materials or dissimilar materials with proper adjustments and precautions.
