## 4 Discussion  
The results of this study act as a basis for detailed parameter investigations for targeted temperature manipulations. To employ large-scale EAM technologies in industrial applications, it is not only necessary to be able to influence the substrate temperature according to the component's requirements but also to engineer the mechanical properties in a defined manner. For this, we compared the results from the manipulated samples to the tensile properties obtained from unheated and uncooled samples at identical temperatures, which were all collected at a traversing speed of 0.160 m/s after determining no influence of the velocity itself on the thermal behavior without active temperature manipulation, since only the layer duration affected the achieved substrate temperature. The infrared heating experiments were consistent with the hypothesis that the interlayer bond strength is a function of the substrate temperature, and when this is actively increased, the bond strength converges to that of unheated samples manufactured at that exact target temperature. This is particularly visible in the close agreement of the heated results. For these, the gray surfaces in Figures 3-5 represent the achieved tensile strength and modulus for unmanipulated or unheated samples at the representative heated substrate temperatures of this investigation. It was expected that the strength and modulus  
Figure 11: Standard and nominal transverse tensile strength of the cooled specimens at 50 mm cooling distance with the reference tensile strengths for unheated specimens at the achieved heated temperatures. Figure 12: Standard and nominal transverse tensile modulus of the cooled specimens at 100 mm cooling distance with the reference tensile strengths for unheated specimens at the achieved heated temperatures. should rise from the level of the red surface, which corresponded to unheated samples at the identical layer time, to that of the gray surface. As can be seen in Figures 3-5, the tensile modulus remained slightly below the target values at higher substrate temperatures, while the tensile strength even exceeded the target strength for most setups. This was attributed to be more an effect of difficult determination of the actual substrate temperature at deposition than to be relevant and significant process behavior. The numerical results in the transverse direction showed a trend toward higher tensile strengths for the setups manufactured at 0.080 m/s compared to those at 0.160 m/s. This may be due to the twice as long passing time of the infrared emitters over each point of the path and thus a higher heat input, which in turn affects the crystallinity within each strand, leading to higher tensile strengths. At higher target temperatures, which are within the ideal processing window, the tensile strength exceeded the expected reference strength considerably, while the lower temperatures resulted in tensile strengths slightly lower than expected. This may again be due to greater crystal growth at lower temperatures, which may not get fully melted upon reheating at moderate temperatures, leading to limited fusion bonding across the interface [25]. It must also be noted that the impact of the heating process was considerably higher for lower substrate temperatures in regard to the tensile strength. Samples at unmanipulated substrate temperatures below the mentioned processing window, and thus below the onset of crystallization, obtained significantly lower tensile strengths compared to substrate temperatures within the processing window. Through infrared heating, these low-strength values were considerably increased, yielding an increase in strength of up to 32% for the single-walled tensile strength with regard to the strand width and up to 37% for the nominal tensile strength. While the tensile modulus did not obtain such strong increases, an improvement of up to 12% for the overall tensile modulus and up to 17% for the nominal tensile modulus were determined.