The ability to verify a castings integrity without damaging it is in many cases extremely useful. We have in house Dye Penetrant inspection (DPI) facilities with a certified Level 2 inspector. We regularly use subcontractors for x-ray facilities should an order specified the need. Given some of the critical applications that our castings are used in these provided confidence to the end user that the part is suitable and its integrity is sound.
Dye Pentrant Inspection
This process aims to find surface flaws that show porosity that is deeper than just a surface imperfection. The casting is submerged in the dye and the allowed to leach into any pores before being washed off with water. The castings are then thoroughly dried in an oven before being allowed to cool. A developer is then sprayed onto the castings which leaves a chalk like white coating of the casting. If dye has found its way into a defect in the casting this will be leached out by the developer and can easily be seen by the inspector.
Dependent on the size of the defects and they density the casting can either be accepted, reworked or rejected. This is a very useful process for identifying surface faults that would otherwise be invisible and gives a tell tale sign that a bigger problem may be underneath the skin of the casting. It is also very useful for the identification of
To check a castings integrity as thoroughly as possible without changing it then x-ray is used to ascertain whether defect exist internally. This is the best way of ensuring that on machining no defects will be found. It also verifies hat wall thicknesses are as drawn without anything untoward which cannot be identified by eye or other processes. This is usually only specified for safety critical castings.
Ultrasonic Testing Of Casting Integrity
We have in house facilities to ultrasonically test castings for porosity, inclusions and blow holes. This is useful where a quick check of a castings integrity is required instead of having to send for x-ray. It also allows under surface checks which DPI might not pick up.