Phased array ultrasonic inspection method for industrial applications

A method of inspecting a component comprising:

• (a) applying a separate excitation pulse to each of a plurality of transducers forming an array to produce an ultrasonic transmission beam focused into the component along a selected ray path from the array, the array being separated from the component by a standoff with a material velocity vw;
• (b) steering the ultrasonic transmission beam along the selected ray path at an angle θ relative to a surface normal, said steering comprising:
• (i) adjusting a transmit delay profile to compensate for refraction of the ultrasonic transmission beam at the interface between the component and the standoff, the transmit delay profile comprising a plurality of transmit delays, each transmit delay comprising a static steering term, and
• (ii) modulating the excitation pulses with the transmit delay profile;
• (c) generating a plurality of echo signals using the transducers as receive elements;
• and
• (d) processing the echo signals in a plurality of channels using a delay profile, the delay profile comprising a plurality of receive delays, each receive delay comprising a static receive steering term, said processing comprising:
• (i) adjusting each of the static receive steering terms to compensate for refraction of the ultrasonic transmission beam at the interface between the component and the standoff;
• (ii) applying the delay profile to the echo signals in the respective channels to generate a plurality of delayed echo signals;
• and
• (iii) summing the delayed echo signals from the receive elements to generate a steered echo signal.

A method of inspecting a component along a curved surface of the component and across a standoff with a material velocity vw, said inspection method comprising:

• (a) adjusting a transmit delay profile to compensate for at least one surface geometry effect, the transmit delay profile comprising a plurality of transmit delays, each of the transmit delays comprising a static surface geometry term;
• (b) modulating a plurality of excitation signal pulses with the transmit delay profile;
• (c) applying the modulated excitation signal pulses to a plurality of transducers forming an array separated from the component by the standoff, to produce an ultrasonic transmission beam focused into the component along a selected ray path from the array;
• (d) generating a plurality of echo signals using the transducers as receive elements;
• and
• (e) processing the echo signals in a plurality of channels, said processing comprising:
• (i) applying a delay profile to the echo signals in the respective channels to generate a plurality of delayed echo signals that compensate for at least one surface geometry effect, the delay profile comprising a plurality of receive delays, each of the receive delays comprising a static surface geometry term;
• and
• (ii) summing the delayed echo signals from the receive elements to generate a surface geometry effect compensated echo signal.

A single-turn method of inspecting a component having an inspection surface, said single-turn inspection method comprising:

• (a) positioning an array of transducers facing the inspection surface of the component;
• (b) exciting the transducers to produce an ultrasonic transmission beam focused into the component along a selected ray path from the array;
• (c) generating a plurality of echo signals using the transducers as receive elements;
• (d) changing the relative angular orientation of the array and the component around an axis and repeating steps (b) and (c);
• and
• (e) processing the echo signals in a plurality of channels to form at least one processed echo signal,
• wherein the processed echo signals corresponding to a final image of the component are obtained with the relative orientation of the array and the component constrained to rotation around the axis.