Machining and cutting
Waterjet cutting: what goes wrong and where to inspect
Abrasive waterjets cut almost any material without heat: thick aluminium, titanium, composites, stone, glass, rubber and gaskets.
01How the process works
Water at very high pressure is mixed with garnet abrasive and focused through a nozzle. Because there is no heat affected zone, waterjet suits heat sensitive materials and parts that will be welded or bonded.
Edge taper and striation increase with speed and thickness; composites can delaminate at pierce points. Quality levels are usually defined by the cutting speed setting and checked on the first part.
- Material check. Grade and thickness.
- Programming. Quality level and lead-ins set.
- Piercing. Low pressure pierce for brittle materials.
- Cutting. Abrasive jet cuts the profile.
- Inspection. Taper, dimensions, edges.
02What typically goes wrong
| Defect | Typical cause | How it is found |
|---|---|---|
| Edge taper | Speed too high | Calipers at top and bottom |
| Striation | Quality setting | Visual, roughness |
| Delamination | Pierce in composites | Visual, tap test |
| Abrasive embedding | Soft materials | Visual |
| Dimensional error | Nozzle wear | Gauges |
| Corrosion staining | Water left on steel | Visual |
03Where an inspector should look
Before production
- Edge quality level
- Material and thickness
During production
- First part taper
- Nozzle wear
After production
- Dimensions
- Edges and drying
04Standards and references
Customer edge quality definitions; ISO 2768 for general tolerances.
Standards are named for orientation. The applicable edition and acceptance criteria are those in your contract and specification.