Ultrasonic Contact Impedance hardness test
The UCI hardness testing method measures the frequency change of an oscillating rod with a diamond tip upon contact with the material. The resonance shift directly indicates hardness.
Physical-chemical mechanism of action
The UCI hardness testing method uses ultrasound to measure the frequency change of a vibrating rod with a diamond tip. The resonance shift of the rod correlates directly with the hardness of the contact material.
Metallurgical relevance & risks when welding
UCI hardness testing is particularly useful for high-hardness materials like martensite or ferrite. Wrong interpretation can lead to inaccurate hardness levels, affecting strength reliability. It is important to correctly align the rod and perform the measurement in a quiet environment.
Workshop practice & instructions
• Use a vibrating rod with a diamond tip.
• Measure the frequency change when contacting the material.
• Correlate the resonance shift directly with hardness.
• Ensure correct rod alignment and a quiet environment.