Castable magnetic particle flaw detection composition and method using constituents that are non-volatile and resistant to oxidation below 100{20 {0 F and having a viscosity less than 12,000 centipoises

• Main Authors: WELTMAN; HENRY J, HALKIAS; JOHN E, REYNOLDS; JACK D, CARROLL; MARK T, KAARLELA; WILLIAM T
• Format: Patent
• Language: English
• Published: 17.10.1978
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES; PHYSICS; TESTING

A method for forming and preserving a permanent record of inspections of workpieces or the like having drilled holes or other metallic surface conformations characterized by applying a castable, plural component, magnetically active material comprised of room temperature vulcanizing, or polymerizing, rubber containing magnetizable particles and specific sensitizing agents; magnetizing the area to be inspected, so as to cause migration of the particles in the rubber before the viscosity becomes too high for the magnetized particles to migrate to the situs of an imperfection, or flaw; forming a magnetic rubber inspection replica or record of the alignment of the magnetizable particles adjacent the interface between the casting and the workpiece by increasing the viscosity of the rubber above 4000 centipoises and to flexible elastic form so as to immobilize the particles; removing the magnetic rubber inspection record thus formed and inspecting for concentrations of the magnetizable particles to delineate flaws; and carrying out post-inspection procedures. Also disclosed are specific formulations and ingredients thereof, including delineation of components that cure the problems of the prior art.