Checking for Porosity in Metal Castings

Valentine Robotics, a Scorpion Vision integrator in the US has developed a system that can detect porosity in metal. With specialised lighting, the Scorpion Vision system can detect the phenomonen down to 0.5mm. In the recent example of an engine block inspection, the objective was to detect porosity and other surface defects ranging from 0.5mm to 2mm.

Good PartBad Part

In image 1,  the metal appears to be pure white, but in image 2 the porosity clearly stands out against the white surface.

Gear Porosity

Another project required detection of porosity in the teeth of a gear. This kind of application is problematical for vision systems due to issues with shadows and reflective material. With Scorpion Vision, Valentine Robotics were able to solve the problems, as can be seen in the following images.

Good sampled partPorosity detected between the gear teeth

Transmission Housings

Four different machined surfaces were checked simultaneously using medium resolution 1394.b (Firewire 800) cameras.  The tolerance of the porosity was 2mm maximum size with any porosity found no closer than 5mm and no more than 3 per surface area.

Good sampled part

Bad sampled part









 The bad part exhibits porosity. The blue lines are actual measurements between the porose areas. The porosity tolerance calls for the measurement to be no closer than 5mm.

Another example of a diverse application for Scorpion Vision Software. The complexities of porosity detection are dealt with by the integrated vsion tool set and the automatic image sampling/brightness contrast adjustment is used to good effect to negate the issues with back scatter and varying surface types.



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