Martin Byung-Guk Jun's research while affiliated with Purdue University and other places

... Integration of AM with the cold spray process-cold spray additive manufacturing (CSAM) is the solid-state supersonic deposition method that can build 3D components for mass production and remanufacturing [187]. Generalized AM techniques are presented in contrast to traditional AM methods, as shown in Figure 21a [188]. ...

... As shown in Fig. 1b, the morphology of the particles is in quasi-spherical shape, having a size distribution of 10-45 µm where the average diameter (d 50 ) is 17 µm [38]. Sn was selected as the coating material owing to its intrinsic physical and chemical properties of: (i) high corrosion resistance [39,40]; (ii) low melting temperature (232 ℃) [41]; and (iii) soft nature (≈ 7 ±1 HV [42]) to facilitate the self-bonding onto the target polymer surface. Although copper (Cu) can be also considered as the feedstock candidate for FE due to its higher electrical conductivity as compared to Sn, achieving electrical conductivity by cold spraying of Cu on thermoplastics such as PET remains challenging due to the material jetting phenomenon [43]. ...

... Without preheating the carrier-gas flow (i.e., T = 25℃), no successful deposition was observed at room temperature using the rectangular-nozzle configuration. The reason is that rectangular nozzles generate stronger bow-shock due to their larger sectional area, leading to lower particle impact velocity (in our case less than V crit at room temperature) as compared to the axisymmetric nozzles [75,76]. On the other hand, preheating the carrier gas to 80 ℃ (see IR camera image in Fig. S8c, Supporting Information) allowed to achieve of dense and conductive Sn coating (i.e., 12 mm linewidth with single-pass) on the PET surface (Fig. 8d, Supporting Information). ...

... All lines have start and endpoints. The Dexel line array creates the workpiece and specifies the tool length, width, and height; lines are continuously added [8]. During drilling, the rotating bit presses in the downward z-direction onto a stationary workpiece in the location where a hole is required. ...