DE569598C - - Google Patents

Description

GERMAN EMPIRE

ISSUED FEBRUARY 4, 1933

REICH PATENT OFFICE

PATENT LETTERING

CLASS 42 k GROUP 20 os

M 113463 IX j42 k Date of publication of the patent grant: ις>. January

5) ipL-3ng. Otto Mühlhäuser in König, Odenwald

Process for determining the condition of materials, especially for determination

of mistakes in it

Patented in the German Empire from io. January T931 from

The invention particularly relates to a method for determining the condition of materials to detect errors, for example to detect gas bubbles and cavities or cracks in castings, forgings or welds or to determine inhomogeneities. For this purpose, mechanical vibrations (sound vibrations) used, specifically vibrations of the highest frequency (shortest Wavelength), low diffraction, good reflection and high absorption of the oscillation rays to reach. According to the invention, these vibrations are known per se in other areas of investigation Way outside of the material in a vibration transmitter generated by the material and measured at another point by a vibration sensor.

So it becomes the change in the vibrational state determined between the vibration transmitter and the vibration sensor, z. B. by measuring the energy the recorded vibrations. The vibration transmitter can, for example, vibrations of uniform energy in the to be examined send by the vibration sensor at the end of any Can be received through the material. Defects in the material, cavities, cracks or the like cause a Reduction of the vibration energy and a deflection of the vibration waves, so that from the amount of energy to be measured at the end of the oscillation path (recorded Vibration energy j conclusions drawn about the internal structure of the body can be.

The figures show schematically examples for the application of the process according to the invention, namely in

Fig. Ι to search for a cavity in the material, in

Fig. 2 and 3 for the determination of deep cracks, in

Fig. 4 to determine a surface crack.

The same reference numbers relate to the same parts.

Material 1 contains a 5 "as an error Cavity 2 (Fig. 1). It is determined on one side of the material a vibration transmitter 3 placed on the other a vibration sensor 4, which is with is connected to a measuring device, not shown. The oscillation frequency is to be chosen so that the vibrations experience little diffraction at the boundaries of the cavity and also in the cavity be absorbed; So it is so high to choose as So technically achievable. For the Vibration sensor 4 is then the energy absorbed in the position shown close to or equal to zero, in another