Detecting porosity in Aluminium Castings
Detecting porosity in Aluminium Castings
(OP)
Hello,
I thinking of using ultrasonic or x ray porosity detectors to pick up porosity in aluminum die castings. The porosities are located under the surface of a raw casting so we currently only find them after we machine them. We would like to detect porous parts before wasting money on machining. The material thickness of the aluminium casting ranges from 25mm to 3mm and the porosities we want to detect range roughly from 0.4mm to 2.0mm in diameter. The surface of the casting would have a degree of roughness (a maximum being Ra=8) and is also curved, smallest radius being 3mm.
Has anyone had any experience, success or otherwise regarding this
Ideally I'm looking for a quick check performed by hand on the suspect areas of the casting, for each part.
Thanks
I thinking of using ultrasonic or x ray porosity detectors to pick up porosity in aluminum die castings. The porosities are located under the surface of a raw casting so we currently only find them after we machine them. We would like to detect porous parts before wasting money on machining. The material thickness of the aluminium casting ranges from 25mm to 3mm and the porosities we want to detect range roughly from 0.4mm to 2.0mm in diameter. The surface of the casting would have a degree of roughness (a maximum being Ra=8) and is also curved, smallest radius being 3mm.
Has anyone had any experience, success or otherwise regarding this
Ideally I'm looking for a quick check performed by hand on the suspect areas of the casting, for each part.
Thanks





RE: Detecting porosity in Aluminium Castings
It will not tell you the degree of porosity, but some trial and error will tell you an acceptable range.
RE: Detecting porosity in Aluminium Castings
Best regards,
ct
RE: Detecting porosity in Aluminium Castings
How much do you really want to spend on RT or UT? Both methods have there advantages and disadvantages regarding time and possible surface preparation (for UT). I would suggest calling several non-destructive testing companies and have them provide you with an estimate on cost for each process.
You did not mention the size of the component, but in most cases RT (x-ray) is probably the preferred method. You will most likely have to send the pieces out to the lab.
RE: Detecting porosity in Aluminium Castings
Such specification will assure that your castings is up to standard and the supplier is responsible for its quality and testings.
RE: Detecting porosity in Aluminium Castings
Bill
RE: Detecting porosity in Aluminium Castings
RE: Detecting porosity in Aluminium Castings
RE: Detecting porosity in Aluminium Castings
We had the similar problem of wasitn alot of time and possible money machining casting that would subsequently fail at later stages.
Turn around times for these were 4 to 5 mins per casting. We then found out it was good for process checking and you could go and take a few castings off a production line and blast them through the x-ray in a few minutes and you get a result.
Initially the outlay is expensive but you could justify a costing on it based on saving maching costs, tooling and time
As we all know castings are cheap but its the inherent cost in machining and testing that adds the value so catching defects at an early stage is preferable.
id would say that the cost of x-ray (wet film) versus relatime x-ray is a no-brainer. With traditional x-ray you have chemicals, film, disposal and more importantly time loss waitying for result.