NDT TRAINING IN CHENNAI

NON DESTRUCTIVE TESTING

Non-destructive techniques have the advantage of providing data without physical alteration of the electronic device

ULTRASONIC TESTING

Ultrasonic testing (UT) is used in the testing of nearly all solid materials, such as fine-grained aluminum, steels and alloys, composites and plastics – practically any solid material where detection of internal discontinuities or thickness measurements are of most common concern. It is also used in the detection of interlaminar separations and regions that have been improperly processed or damaged in layered composite structures.

MAGNETIC PARTICLE TESTING

Magnetic particle testing (MT) is used to detect discontinuities in ferromagnetic parts – namely parts made of iron, steel, nickel, cobalt and the alloys of these materials. Ferromagnetic materials develop strong internal magnetic fields when an electric current is passed through the part. Magnetic particles are applied to the part and a discontinuity that causes a disruption in the induced magnetic field attracts the applied particles, producing an indication.

LIQUID PENETRANT TESTING

One of the most common ways to enhance visual testing (VT) is through the introduction of highly visible penetrating liquids. These specially prepared liquids, characterized by low a viscosity, easily enter voids open to the surface when the part is dipped into or sprayed by the penetrant. Relatively simple, inexpensive and reliable, liquid penetrant testing (PT) is only used for detecting discontinuities open to the surface. With the correct application, it will detect discontinuities ranging in size from the large to the microscopic.

RADIOGRAPHIC TESTING

Inspection techniques using radiographic testing (RT) are some of the most common approaches to visualizing the internal structures of components, materials and assemblies. The approach requires a source of electromagnetic radiation that can penetrate the item being examined during exposure (the time the item is illuminated by the radiation). Applications for RT are found throughout manufacturing and field-service environments. Raw materials are examined for the presence of internal discontinuities (castings, forgings); fabrications and assemblies are examined for induced discontinuities (welds) and misalignments or absence of internal parts; and inservice inspections use RT for detecting and assessing time-dependant degradation, such as corrosion, cracking and environmental damage.

EDDY CURRENT TESTING

One of the more widely practiced ET techniques is eddy current testing. The flow of eddy currents is affected by fissures, constrictions or other discontinuities that cause distortions in the cross section through which the current is made to flow. Thus, the eddy current technique is useful for detecting the wall thickness of thin materials as well as measuring localized discontinuities. The thickness of the part must be within the depth of penetration (referred to as the skin depth) of the eddy currents and is dependent upon material properties and operating frequency. It is usually less than 0.635 cm (0.25 in.) and may be very much less, particularly for ferromagnetic materials.

VISUAL TESTING

Throughout manufacturing and field inspection, visual testing (VT) is the most widely used NDT method. The presence of a multitude of potential problem areas can be identified by knowledgeable observers, assisted by devices that magnify, qualify or quantify the conditions being evaluated.