Ultrasonic Contact Impedance Hardness Testing

UCI testing allows for hardness testing on metal products with thin surfaces or small masses that are difficult to measure using Dynamic Impact portable testers, in difficult locations where hardness testing could otherwise be difficult or inaccessible. Results can then be converted to industry standard Rockwell, Brinell or Vickers scales for further processing.

Under a fixed load, a vibration bar or probe with a 136 degree diamond tip depresses into a test surface while an Ultrasonic vibration frequency difference is calculated and translated to an associated hardness value.

Reliability

Ultrasonic portable hardness testers have seen explosive growth over recent years as they enable non-destructive tests on small metal parts without damaging or altering them. They’re ideal for inspecting goods upon receipt, mix-up checks, production control processes and maintaining built-in components.

The UCI method employs a mechanical resonator equipped with an indenter at its tip to excite longitudinal vibrations in test material and cause a frequency shift which is measured. When applied force is applied, this frequency can then be converted to Vickers hardness values.

This test is both more accurate than traditional Vickers methods and less destructive to parts. Furthermore, it produces smaller imprints on surfaces similar to Vickers indentation sizes; furthermore it can test objects of minimal thickness with complex shapes as well as surface hardened layers – it meets all ASTM A1038 criteria and can easily be calibrated against individual specimens or sets of test specimens.

Accuracy

Accuracy in hardness testing refers to how closely measured values compare to an accepted standard, while precision measures how closely repeated measurements fall within given conditions. Qualitest’s UCI portable hardness tester uses ultrasonic contact impedance testing methods for comparative test results across different materials.

This technique, known as the modified Vickers procedure, allows electronic evaluation of each indentation size created by a probe under a given test load in a fraction of a second and digital display of results. Furthermore, this test method can measure hardness in areas difficult to access by traditional surface testing methods, such as gear teeth bases.

Under the nondestructive dynamic Leeb method, a mechanical impact resonator is thrust against a test surface and measures both rebound speed and any change in frequency due to impact; these measurements are then converted into hardness values using conversion tables.

Safety

Ultrasonic testing is a nondestructive testing method, meaning it does not permanently alter the surface being tested. UCI also allows hardness tests on surfaces which cannot easily be examined with other devices like rebound testing or Brinell testing.

Portable hardness testers are simple and straightforward ways of performing hardness tests in areas not accessible by larger stationary units. Perfect for testing any metal product and measuring areas that cannot be measured using traditional means, portable hardness testers make measuring hardness much simpler and accurate than ever before.

Portable hardness testers consist of a probe and host connected by cable. The probe features a vibration bar equipped with a Vickers diamond (more commonly known as Vickers diamond), which presses against a work piece under fixed load conditions and displays digitally its hardness measurement value; this method is known as the modified Vickers test and has been standardized under ASTM A1038.

Applications

Portable UCI hardness testers use vibration and frequency to assess hardness values without leaving an indentation on your work piece’s surface. As a result, this non-destructive method can save thousands in manufacturing costs due to scrap parts as well as reduce downtime due to repair issues.

These UCI portables make hardness measurements in difficult-to-access areas with Leeb probes in less than 2 seconds and feature accurate display and printing of measured values as well as value conversion among major hardness scales.

Qualitest’s UCI portables are specially-crafted for field and workshop applications, providing mass storage, easy calibration and multiple programming functions that make them the perfect tool for measuring the hardness of small fogging, cast material, weld inspections, heat-affected zones, ion-nitride stamping dies/molds/forms/presses, forms, presses thin walled parts bearings or tooth flanks. Compatible with popular hardness scales they come in various models for easier measurement.