Involves use of a laser to melt the bond line between two parts to form a weld. Which welding method is this?

• A. MIG
• B. TIG
• C. Plasma arc
• D. Laser welding

Answer: (D)

The key idea is that the joint is melted by a focused laser beam. Laser welding uses a concentrated laser to heat and melt the bond line between the two parts, so the molten metal fuses as it cools to form the weld. Because the energy is highly localized, laser welding can produce very precise, deep, or narrow welds with minimal heat-affected zone and distortion. This is different from MIG or TIG, which use an electric arc (with or without a filler wire) to melt the metal, and from plasma arc welding, which uses a plasma arc as the heat source. The description explicitly mentions a laser, so the method is laser welding.