Ultra-sonic testing of metal bodies

Claim 1

IN A METHOD FOR TESTING A BODY OF METAL SELECTED FROM THE GROUP CONSISTING OF TITANIUM, ZIRCONIUM, TANTALUMN, ALUMINIUM, MAGNESIUM AND ALLOYS OF WHICH THEY CONSTITUTE A MAJOR PORTION, FOR STRUCUTAL DEFECTS IN WHICH AT LEAST A PORTION OF SAID METAL BODY IS IMMERSED IN AN AQUEOUS SOLUTION HELD IN A CONTAINER AND ULTRA-SONIC VIBRATIONS ARE APPLIED TO AN IMMERSED SURFACE OF SAID METAL BODY FROM A PROBE THROUGH SAID SOLUTION DURING RELATIVE MOVEMENT BETWEEN SAID PROBE AND SAID METAL BODY, STRUCTURAL DEFECTS IN SAID METAL BODY BEING INDICATED BY ANOMALIES IN THE REFLECTION OF SAID SONIC VIBRATIONS BACK TO SAID PROBE, THE IMPROVEMENT WHICH COMPRISE: (A) PROVIDING ELECTRIC CURRENT CONDUCTING IONS IN SAID AQUEOUS SOLUTION, (B) APPLYING A DIRECT ELECTRIC CURRENT BETWEEN SAID METAL BODY AND AN ELECTRODES IMMERSED IN SAID AQUEOUS SOLUTION ADJACENT SAID PROBE AND IN FIXED LOCATION RELATIVE THERETO AND ADJACENT SAID METAL BODY, WITH THE SAID METAL BODY BEING CONNECTED TO THE POSITIVE POLE OF SAID CURRENT AND THE SAID ELECTRODE BEING CONNECTED TO THE NEGATIVE POLE THEREOF, (C) SAID CURRENT BEING OF SUFFICIENT VOLTAGE TO PRODUCE A COLORED ANODIC OXIDE FILM ON AN AREA OF THE SURFACE OF SAID METAL BODY ADJACENT THE END OF ELECTRODE, AND, (D) SAID CURRENT BEING APPLIED TO PRODUCE SAID CLORED FILM ONLY WHEN AN ANOMALY IN VIBRATIONS REFLECTED BACK TO SAID PROBE INDICATES A STRUCTURAL DEFECT IN SAID BODY.