In wave terms, what does 'refraction' describe?

Refraction describes the change in direction of a wave as it transitions from one medium to another. This phenomenon occurs because waves travel at different speeds in different materials. When a wave enters a new medium, its speed changes, causing it to bend at the boundary between the two materials. This bending of the wave can significantly affect how signals or energy propagate through various materials, which is especially important in nondestructive testing techniques like ultrasonic testing.

Understanding refraction is crucial in many applications, including NDT, as it influences how sound waves penetrate materials and interact with flaws or discontinuities. Recognizing this concept helps technicians properly interpret the signals received from the ultrasonic equipment, leading to more accurate assessments of structural integrity and material properties.