From impact to solidification in drop-on-demand metal additive manufacturing using MetalJet

Metal Droplet Deposition: From Foundation to Engineering Manufacturing

“…This is due to the slow upward motion of the solidification front and the reduction of the oscillation period. [16,30,31] A deeper study considered the effect of deposition conditions on ripple morphology. For example, an increase in substrate temperature prolongs the time for droplets to solidify, which is longer than the damping cycle.…”

“…This is due to the slow upward motion of the solidification front and the reduction of the oscillation period. [ 16,30,31 ]…”

“…Reproduced with permission. [ 16 ] Copyright 2022, Elsevier. c) Surface ripple morphologies of solder drops at different impact speeds.…”

“…Increasing the contact thermal resistance or decreasing the thermal conductivity will also lead to a longer solidification time of the droplet, resulting in a smoother droplet surface. [ 15,16,38 ] However, increasing the droplet impact velocity will shorten the solidification time and reduce the number of oscillations in the fluid portion of the droplet in a limited time, which will lead to a decrease in the number of ripples and an increase in ripple spacing ( Figure 6c ) . [ 14,41 ]…”

“…[10][11][12][13] Featured ripples may occur on the droplet surface after the droplets are deposited on the substrate because of the interaction between underdamped oscillation and nonisothermal solidification. [14][15][16] Suppose droplets impact the substrate at high speed, in that case, the rapid solidification of the droplet spreading front may interfere with the liquid flow, and some finger-like structures may be generated on the sedimentary edge. [17][18][19] These particular phenomena of metal droplet deposition have attracted more attention from researchers.…”