Workshop 2: ✂️ Laser Cutting¶

Industrial Workshop 2 of 7

Laser Cutting

Try it live

Explore this on the interactive simulator with real-time sliders and graphs: 🔬 Launch in Simulator

Workshop Brief¶

Cut a 5 mm mild-steel plate with a CO₂ laser using oxygen assist gas. Aim for a narrow, smooth kerf with no dross (re-solidified molten metal) adhering to the bottom edge.

Specifications: Material: Mild steel, 5 mm · Assist gas: O₂ · Dross-free edge

Process Theory¶

In laser cutting, a continuous-wave (or high repetition-rate pulsed) laser beam melts (and, with oxygen assist gas, exothermically oxidizes) a narrow kerf through the material, while a coaxial assist-gas jet blows the molten/oxidized material out of the kerf from below.

Laser power and cutting speed together set the linear energy density delivered to the material: too much power or too slow a traverse speed overheats the kerf, allowing molten material to re-solidify on the underside as dross; too little power or too fast a traverse fails to fully penetrate the plate.

The assist-gas pressure must be high enough to clear molten material from the kerf efficiently (oxygen additionally provides exothermic heating that assists cutting of ferrous metals) but not so high as to cause turbulent melt ejection that roughens the cut edge.

Process Parameters¶

Parameter	Range	Unit
Laser power	500 – 3500	W
Cutting speed	300 – 3000	mm/min
Assist gas pressure	0.5 – 10	bar

Procedure¶

Record the precision score at the default power, speed and gas pressure.
Vary laser power alone (holding speed and gas pressure fixed) and record the precision score at each value.
Repeat, varying cutting speed alone, then assist-gas pressure alone.
Determine the parameter combination that achieves a dross-free, full-penetration cut with a 100% precision score.

Observation Table¶

Table: Effect of CO₂ laser cutting parameters on edge quality

Trial	Power (W)	Speed (mm/min)	Gas pressure (bar)	Precision score (%)	Verdict
1
2
3
4
5
6
7
8

Graph¶

Plot Precision score (%) (y-axis) against Cutting speed (mm/min) (x-axis).

Expected trend: an optimum band of speed for fixed power/pressure — too slow causes dross, too fast fails to penetrate.

Precision score vs cutting speed, holding power and gas pressure fixed

📈 Graph paper / plot area — attach printed or digital graph here

Calculation¶

Estimate the linear energy density delivered as (Power / Speed) for each trial and relate it qualitatively to the observed precision score.
State the final optimized (Power, Speed, Gas pressure) combination reaching certification.

Result¶

Table: Optimized parameter set for laser cutting

Power (W)	Speed (mm/min)	Gas pressure (bar)	Final precision (%)	Certified? (Y/N)
1

Precautions¶

Keep two of the three parameters fixed while sweeping the third, to isolate individual effects.
Watch for the characteristic dross-formation trend at low speed/high power before assuming higher power is always better.