Intense Pulsed Ion Beam Irradiation Ti Fund Is A Surface Ablation Of The Role Of Research

The experimental investigations of the surface ablation behaviors and its mechanism on Ti-based metallic materials irradiated by high-intensity pulsed ion beam (HIPIB) have been carried out in a TEMP-6-type HIPIB apparatus. The temperature field evolvement and theoretical calculation of ablation process have also been investigated. The irradiation of pure Ti by a HIPIB apparatus was performed which has an external-magnetic field MID with polymer anode and operated in unipolar pulse mode. It has been found that the ablated surface morphologies for Ti samples have a trend from roughing to smoothing with increasing the shot number. The micro non-uniformity of geometrical factor and composition on the irradiated surface of pure metals, e.g. micro-protrusions, small defects and impurities etc., induced a selective ablation under HIPIB irradiation, which is the main mechanism for cratering formation on pure metals. The ablated surface morphologies for y-TiAl intermetallics irradiated by HIPIB were significantly different from that of pure Ti, presenting a wavy feature and cracks occurred on grain boundaries. A selective ablation of Al was confirmed by the fact that new phases of Ti3Al and Ti2Al have formed in sequence on the irradiated surface with increasing the shot number. The y-TiAl intermetallics underwent a melting and evaporation process, resulting in high gradient of temperature field nearby the metallic materials surface. A high surface stress was produced in the surface layer in the sequent solidification process, which exceeded the strength of -TiAl, and made the surface cracking. The theoretical model of heat transfer during phase transformation in the metals irradiated by HIPIB has been established according to the conduction characterization of metallic materials. The temperature field in Ti irradiated by HIPIB was calculated using an axisymmetric model based on enthalpy formulation. The similar ablation mass calculated to measured mass was obtained for the titanium irradiated by HIPIB under 70 J/cm2.