Ultrasonic hardness testing
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This document discusses hardness testing methods. It defines hardness as the resistance to indentation or penetration in metallurgy. Hardness testing is performed for research and application purposes. The common hardness testing methods described are Brinell, Rockwell, Vicker, and ultrasonic hardness testing. Ultrasonic hardness testing uses piezoelectric transducers to convert ultrasonic frequencies into mechanical force and indentation, then measures the frequency shift to determine hardness.
Ultrasonic hardness testing
- 2. For more help contact me Muhammad Umair Bukhari Engr.umair.bukhari@gmail.com http://onlinemetallurgy.com
- 3. What is hardness ? Different fields have different concepts In metallurgy “the resistance to indent formation or penetration is called hardness”.
- 4. Why hardness testing? It is done mainly for two reasons: • For research purpose • For application purpose
- 5. How to measure hardness? There are some well known following methods; o Brinell hardness (HB) o Rockwell hardness (HRC) o Vicker hardness (HV) o Ultrasonic hardness (UCI) Note: there is no conversion of one scale to another.
- 6. Ultrasonic Hardness • Basic principle: In UCI material is indented by converting electronic frequency into mechanic force and the indentation area size is calculated as a function of electronic frequency.
- 7. Process description • It is the modified form of Vicker’s hardness testing • Ultrasonic frequency is converted into mechanical force/vidration by Piezo transducer • And the frequency shift is measured with Piezo reciever • Material is indented with Vicker’s oscillating diamond-tipped rod
- 8. Continue…… • Rod is oscillated at a particular frequency • Material is indented with a constant force • All the process completes in very short time
- 9. Continue…. • Vicker hardness equation HV= F/A above equation is modified for ultrasonic frequency shift
- 10. Piezoelectric Material: • A piezoelectric sensor is a device that uses the piezoelectric effect to measure pressure, acceleration, strain or force by converting them to an electrical signal.