PSI - Issue 30

Anna Zykova et al. / Procedia Structural Integrity 30 (2020) 216–223 Anna Zykov et al. / Structural Integrity Procedia 00 (2020) 00 – 00

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Fig. 1. Scheme of 3D-printing of wall-shaped samples by additive electron-beam manufacturing.

Three variable parameters were used to analyze the effect of various modes on the walls formation from AISI 304 steel wire: electron-beam current ( I e , mA), linear print speed ( V w , mm/min) and layer fill factor ( k ). By the layer fill factor is understood the coefficient k = 1, where 1 corresponds to 100% filling of the one layer volume with molten wire material determined by the equation (1):



k V V 

(1)

where V  – wire feed speed, mm/min; V – sample feed speed, mm/min. The accelerating voltage was left unchanged – 30 kV. The thermal contribution was estimated through the linear energy parameter (E) according to the equation (2): UI E V  (2) where U – accelerating voltage, kV; I – current, mA; V – wire feed speed, mm/min. Tables 1 and 2 present data on the planning of experiments series indicating combinations of process parameters of a multi-beam electron-beam additive manufacturing of AISI 304 steel wire products. Table 1 shows the minimum (–) and maximum (+) parameter values, while table 2 demonstrates which modes correspond to certain combinations of maximum and minimum parameter values.

Table 1. Process parameters for electron-beam additive manufacturing of AISI 304 steel wire walls. Parameter Minimum value (–) Maximum value (+) Voltage, kV 30 30 Current, mA 40 65 Linear speed, mm/min 180 320 Layer fill factor 0.9 1.3

2.3. Research of the samples

Mechanical properties were determined on a universal testing machine UTS-110M by testing samples cut horizontally from the “walls” ( x -direction in Fig. 1). Tests were carried out in tension with a strain rate of