Induced stress wave on the materials surface irradiated by high-intensity pulsed ion beam

摘要

The induced stress wave in pure metal Al and Ti, and thermal barrier coating (TBC) on heat-resistant steel irradiated by high-intensity pulsed ion beam (HIPIB) with ion current density of 200 and 350 A/cm2 and shot number of 1–10 at accelerating voltage of 350 kV with a pulse width of 75 ns (full width at half maximum) has been dynamically measured using lead–zirconte–titanate (PZT) piezoelectric sensor. The measured waveform showing a process of loading, unloading and oscillating is detected as a series of positive–negative pulses, in which the peak value of the first negative pulse represents the maximal intensity of the stress wave. For Al sample the intensity of stress wave is about 40 MPa at 200 A/cm2 and about 78 MPa at 350 A/cm2. At 350 A/cm2, the intensity of stress wave for Ti sample is about 36 MPa. During ablation, the intensity of stress wave for Al irradiated at 200 A/cm2 is similar to that of Ti at 350 A/cm2, due to the different melting and vaporizing behavior. For TBC sample, its high melting temperature and porous structure cause the decreasing intensity to 18 MPa. At 350 A/cm2, the peak intensity of stress wave for the pure Al and Ti irradiated during 10 shots is in the range of 70–90 MPa and 27–40 MPa, respectively, and for the TBC is 15–20 MPa. The fluctuation of stress wave intensity is attributed to the selective ablation caused by the micro-non-uniformity on the sample surface with different mass loss per shot. It is found that the structure and properties of materials have an effect on the formation and transmission of the induced stress wave in the materials under the irradiation conditions.