PSI - Issue 30

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

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Anna Zykova et al. / Structural Integrity Procedia 00 (2020) 000–000

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1. Introduction Additive manufacturing (AM) technologies are constantly developing every year, expanding the range of capabilities to produce metal products from powder, wire or sheets (plates). The main difference between additive manufacturing and other traditional manufacturing processes, such as casting, forging or machining, is that AM forms material layer by layer, does not require tools and can produce parts with geometry that is difficult to obtain using other processes. There are many works in the literature on various AM processes, such as selective laser melting, selective laser sintering or electron-beam melting, such as carried out by Duarte, (2020), Cai (2020), Gong (2020), Aboulkhair (2019). Currently the use of additive electron-beam wire production technologies is gaining relevance for the manufacture of products as shown by Wang (2018), Tarasov (2018). Wire technologies of additive manufacturing have higher productivity than technologies based on layer-by-layer fusion of powder material. Also the use of wire in the AM leads to a lower cost of the raw material in comparison with powder technologies. Today, additive manufacturing wire technology produces a large number of different steels, by Gong (2020), Tarasov (2019), Khodabakhshi (2020), Wang (2018), Bajaj (2020). The structural components of the matrix (austenite, ferrite, martensite), as well as various phases of deposition (intermetallic compounds, carbides) create huge differences in the microstructure and mechanical properties of this class of alloys. This is typical for steels produced by additive manufacturing, as well as for steels produced in the traditional way. In addition, the main factor in AM products is the thermal process parameters, which in turn affect the shape, height of the printed product, the angle of inclination of the walls from the print plane, etc. It should be noted that in the modern literature there is a lack of information about the influence of technological parameters on the process of electron-beam additive manufacturing of steel products, its microstructure and properties, as pointed by Wanjara (2007), Weglowski (2018). Based on this, the aim of the work was to study the influence of technological parameters (wire feed speed, beam current, speed of movement) on the stability of the process of layer-by-layer deposition and formation of products from AISI 304 wire by the method of electron-beam additive manufacturing, study of the structure and properties of products.

Nomenclature AM

additive manufacturing accelerating voltage, kV electron-beam current, mA linear print speed, mm/min wire feed speed, mm/min sample feed speed, mm/min linear energy parameter, kJ/m layer fill factor

U I e

V w

k

V 

V E

2. Materials and methods 2.1. Materials

As a raw material for the formation of products by the electron-beam additive manufacturing method, a solid wire of AISI 304 steel was used, with a diameter of 1 mm. The similar steel AISI 304 of 5 mm thick was used as a substrate. Chemical composition of AISI 304 steel, wt. %: 0.12C, 9.1Ni, 19.1Cr, 0.95Si, balance Fe.

2.2. Equipment and process parameters

In the process of electron-beam additive manufacturing, the wall-shaped products were made (see Fig. 1). The walls were produced using experimental equipment for wire electron-beam additive manufacturing at the Institute of Strength Physics and Materials Science SB RAS according to the scheme shown on Fig. 1.