In-Process Non-Destructive Microweld Inspection Techniques

Degradation of weld strength beyond that which is unacceptable in the end product can always be detected non-destructively. This detection is best made during the weld cycle by monitoring a combination of three parameters: voltage pulse, infrared radiation, and setdown. Other measurements evaluated but found impractical are: eddy current, joint resistance, and sonic/ultrasonic methods. Laboratory experiments show that weld criteria and instrumentation are easily developed.