Figure 5
(a–e) The high-speed IR observations of different processing conditions at the frame right before the laser shuts off. The last two (d and e) have strong vapor plumes indicating a keyhole. (f–j and p–t) The high-spatial IR observations of different processing conditions at the frame right before the laser shuts off where i, j, r, s, t have fringe patterns, which indicate a keyhole. (k–o and u–y) The corresponding x-ray images right before the laser shuts off, where yellow dashes indicate the solid–liquid boundary and red dashes indicate the liquid–gas boundary. (Temperatures all in °C).
