Laser Welding Course

Lesson 1 • Laser Beam Characteristics

Examines wavelength, coherence, divergence, and beam quality factor M². Links beam properties to their practical effects on welding performance.

Lesson 2 • Laser Safety Fundamentals

Defines hazard classes, maximum permissible exposure, and required controls. Compliance with safety standards is mandatory before any hands-on practice.

Lesson 3 • Principles of Laser Light Generation

Covers stimulated emission, population inversion, and resonator design. Establishes the physics basis needed to understand all subsequent laser welding concepts.

Lesson 1 • Plasma and Plume Dynamics

Describes laser-induced plasma formation, plume absorption, and their effect on beam delivery. Managing these phenomena prevents power loss and weld defects.

Lesson 2 • Heat Generation and Conduction

Analyzes thermal diffusivity, heat-affected zone formation, and cooling rates. Understanding heat flow is essential for controlling weld geometry and microstructure.

Lesson 3 • Solidification and Microstructure Basics

Introduces solidification front velocity, grain structure, and phase transformations in laser welds. Provides the metallurgical context for quality evaluation later.

Lesson 4 • Conduction vs. Keyhole Welding Modes

Distinguishes shallow conduction welds from deep-penetration keyhole welds. Mode selection drives parameter choices taught throughout the course.

Lesson 1 • Beam Delivery and Focusing Optics

Examines fiber cables, collimators, focusing lenses, and scan heads. Correct optical setup determines spot size and power density at the workpiece.

Lesson 2 • Shielding Gas Delivery Systems

Describes gas types, flow rates, nozzle designs, and purge chambers. Proper shielding prevents oxidation and plasma interference during welding.

Lesson 3 • Control Software and HMI Operation

Introduces parameter input, recipe management, and alarm handling in welding control software. Proficiency here enables efficient setup and troubleshooting.

Lesson 4 • Motion Systems and Fixturing

Reviews CNC stages, robotic arms, and workholding fixtures used in laser welding. Accurate motion control directly affects seam quality and repeatability.

Lesson 1 • Pulse Parameters for Pulsed Lasers

Covers pulse frequency, duration, and duty cycle for pulsed Nd:YAG and fiber lasers. Pulsed operation enables precise energy control on thin and reflective materials.

Lesson 2 • Focus Position and Spot Size

Explains focal plane location relative to the workpiece surface and its effect on power density. Precise focus control is critical for keyhole stability.

Lesson 3 • Laser Power and Energy Density

Defines peak power, average power, and energy density, and links each to weld penetration. Forms the primary control lever for all parameter optimization work.

Lesson 4 • Welding Speed and Line Energy

Analyzes how travel speed affects heat input, bead width, and dilution. Balancing speed with power is central to achieving consistent weld quality.

Lesson 1 • Surface Preparation and Cleanliness

Details degreasing, oxide removal, and surface roughness requirements before welding. Contamination is a leading cause of porosity and spatter in laser welds.

Lesson 2 • Fixturing for Tight Fit-Up

Covers fixture design principles that maintain gap and alignment under thermal distortion. Good fixturing is the foundation of repeatable production welding.

Lesson 3 • Gap and Mismatch Tolerances

Quantifies allowable gap and step mismatch for keyhole and conduction welds. Exceeding tolerances causes incomplete fusion and porosity, covered in Chapter 6.

Lesson 4 • Dissimilar Material Joint Considerations

Addresses metallurgical compatibility, offset beam positioning, and filler use for dissimilar joints. Prepares students for advanced applications in Chapter 7.

Lesson 1 • Visual and Dimensional Inspection

Covers optical microscopy, profilometry, and cross-section macrography for weld evaluation. These methods provide immediate feedback during process development.

Lesson 2 • Weld Quality Acceptance Criteria

Defines dimensional, visual, and mechanical acceptance standards for laser welds. Establishes the quality baseline against which all inspection results are judged.

Lesson 3 • Non-Destructive Testing Methods

Introduces radiography, ultrasonic testing, and dye-penetrant inspection for laser welds. NDT enables 100% inspection of critical components without destruction.

Lesson 4 • Corrective Action and Root Cause Analysis

Applies fishbone diagrams and 5-Why analysis to laser weld defect scenarios. Systematic root cause methods prevent defect recurrence in production.

Lesson 1 • Multi-Beam and Beam-Shaping Techniques

Examines beam splitting, ring-mode optics, and spatial beam shaping to control melt pool dynamics. These techniques reduce porosity and improve weld geometry in difficult alloys.

Lesson 2 • Laser Welding of Plastics and Dissimilar Pairs

Introduces transmission laser welding of polymers and metal-to-polymer joining. Expands student capability beyond metals to emerging multi-material assemblies.

Lesson 3 • Remote Laser Welding

Covers scan head optics, long focal length systems, and high-speed trajectory programming. Remote welding dramatically increases throughput in automotive and electronics assembly.

Lesson 4 • Laser-Arc Hybrid Welding

Integrates laser with MIG or TIG arc to improve gap bridging and deposition rate. Hybrid processes combine laser speed with arc gap tolerance for thick-section work.

Lesson 1 • Statistical Process Control for Welding

Applies control charts, Cpk analysis, and measurement system analysis to welding data. SPC transforms monitoring data into actionable process stability metrics.

Lesson 2 • Closed-Loop Control Systems

Explains PID controllers, adaptive power control, and seam tracking for automated correction. Closed-loop systems maintain weld quality despite part variation and drift.

Lesson 3 • In-Process Monitoring Technologies

Reviews photodiode, pyrometer, and camera-based sensors for real-time weld monitoring. Sensor data enables closed-loop control and early defect detection.

Lesson 4 • Process Qualification and Procedure Approval

Guides students through welding procedure specification, qualification testing, and documentation. Formal qualification is required before production release in regulated industries.