Abstract: A laser absorptivity measurement device uses a linearly polarized incident beam, an optical configuration comprising an internal polarizing beamsplitter that transmits the linearly polarized incident beam and a quarter-wave plate that converts linearly polarized incident beam into a circularly polarized incident beam that is reflected off a processing substrate. The quarter-wave plate and polarizing beamsplitter can then direct the reflected light back into an integrating volume, where the power of the reflected light can be measured by a photodetector. The laser absorptivity measurement device is capable of making real-time absorption efficiency measurements of a variety of laser-based processes, including laser welding and brazing, additive manufacturing, and laser marking.

Abstract: A laser absorptivity measurement device uses a linearly polarized incident beam, an optical configuration comprising an internal polarizing beamsplitter that transmits the linearly polarized incident beam and a quarter-wave plate that converts linearly polarized incident beam into a circularly polarized incident beam that is reflected off a processing substrate. The quarter-wave plate and polarizing beamsplitter can then direct the reflected light back into an integrating volume, where the power of the reflected light can be measured by a photodetector. The laser absorptivity measurement device is capable of making real-time absorption efficiency measurements of a variety of laser-based processes, including laser welding and brazing, additive manufacturing, and laser marking.

Abstract: Systems and methods for calculating efficiency of a rotary friction welding process are described herein. An example method can include measuring kinetic energy transferred from a welding machine to an interface of a welded joint, and calculating an efficiency of a rotary friction welding process based on the measured kinetic energy. For example, a workpiece torque experienced by a sample can be measured, and an energy associated with the workpiece torque can be calculated. The efficiency of the rotary friction welding process can then be calculated using the energy associated with the workpiece torque.

Abstract: Systems and methods for calculating efficiency of a rotary friction welding process are described herein. An example method can include measuring kinetic energy transferred from a welding machine to an interface of a welded joint, and calculating an efficiency of a rotary friction welding process based on the measured kinetic energy. For example, a workpiece torque experienced by a sample can be measured, and an energy associated with the workpiece torque can be calculated. The efficiency of the rotary friction welding process can then be calculated using the energy associated with the workpiece torque.