OBRABOTKAMETALLOV Vol. 23 No. 3 2021 MATERIAL SCIENCE EQUIPMENT. INSTRUMENTS 7 2 5 products for the formation of high-quality bimetallic specimens with sharp and smooth interfaces, and heterogeneous structure based on copper and iron alloys. To achieve this aim, the following tasks were solved during the research: – establishing the ranges of heat input values when applying layers based on iron and copper alloys for the formation of a sharp interface, which depend on the values of voltage and current required for the formation of the melt pool; – determining the ratio of feed rates of wires into the melt pool for the formation of a smooth interface; – studying the influence of the type of printing strategy depending on the percentage ratio of the volume of dissimilar alloys with simultaneous feeding of wires into the melt pool. Research methodology Bimetallic specimens with different interface designs and heterogeneous structures were obtained using a laboratory experimental installation for additive electron beam manufacturing of metal products at ISPMS SB RAS (Fig. 1). Iron and copper alloys were selected as dissimilar materials. For iron alloys, 1.0 mm diameter wires of stainless steel AISI 321 and structural low-alloy steel 0.09 C-2 Mn-Si were used, while for copper alloys, 1.2 mm diameter wires of technically pure copper M1 and tin-free bronze Cu-9 Al-2 Mn (Table 1) were used. The selection of these alloys was based on their wide practical applications (shipbuilding, aircraft construction, mechanical engineering, etc.). Fig. 1. Vacuum chamber of the laboratory experimental installation for electron beam additive manufacturing Ta b l e 1 Chemical composition of wire feedstock: iron and copper alloys Material Chemical composition, wt.% Fe Cu Cr Ni Mn Al Si C Other Substrate AISI 304 Bal. ≤ 0.3 17‑19 9‑11 ≤ 2 – ≤ 0.8 ≤ 0.08 to 1.1 Wire AISI 321 Bal. ≤ 0.3 17‑19 9‑11 ≤ 2 – ≤ 0.8 ≤ 0.12 ≤ 0.6 M1 ≤ 0.005 Bal. – to 0.002 – – – – ≤ 0.02 0.09 C-2 Mn-Si Bal. ≤ 0.3 to 0.3 to 0.3 1.3‑1.7 – 0.5‑0.8 ≤ 0.12 ≤ 0.28 Cu-9 Al-2 Mn ≤ 0.5 Bal. – – 1.5‑2.5 8‑10 to 0.1 – ≤ 1.65
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