Before the first pulse
Material Preparation Guide
Prepare common laser welding materials with surface cleaning, oxide control, fixture checks, shielding readiness, and crack-risk planning.
SurfaceClean metal
Remove oil, oxide, coating residue, and loose particles before trials.
Fit-upStable gap
Clamp parts so the joint gap does not change across the sample.
ShieldingGas coverage
Set gas type, flow, nozzle distance, and purge before judging weld quality.
Material preparation by family
| Material | Preparation action | Watch for |
|---|---|---|
| Stainless steel | Degrease, remove fingerprints, and keep stainless tooling separate from carbon steel. | Heat tint, porosity, oxide film, and chromium-depletion concerns. |
| Aluminum | Remove oxide close to welding time and avoid touching the cleaned surface. | Porosity from moisture or oxide; unstable coupling from inconsistent surface prep. |
| Copper | Clean oxide and oil; keep contact pressure and surface flatness consistent. | High reflectivity, high conductivity, and variation between plated and bare copper. |
| Titanium | Apply clean handling, dry shielding gas, and trailing or backside shielding when needed. | Discoloration, oxygen pickup, and brittle surface contamination. |
Fixture checks before welding
| Check | Action | Reason |
|---|---|---|
| Joint gap | Measure at several points before clamping and after clamping. | Gap changes can look like parameter instability. |
| Part movement | Mark reference points and inspect movement after tack or first pulse. | Movement changes focus, penetration, and bead width. |
| Thermal contact | Keep backing bars, chill blocks, and copper fixtures consistent across trials. | Heat sinking changes penetration and HAZ width. |
Next engineering checks
Crack Risk CalculatorScreen material, carbon equivalent, restraint, and cooling assumptions for crack risk.Preheat Temperature CalculatorEstimate preheat needs for steels using carbon-equivalent and thickness assumptions.Material Process Window TableControlled-variable matrix for material family, surface preparation, fixture setup, and release checks.Defect Troubleshooting TableTrace weld defects from visible symptoms to first controlled checks, adjustment choices, section triggers, and next-step validation.