Alexander Panfilov

EFFECT OF HEAT TREATMENT ON THE STRUCTURE AND PROPERTIES OF TI6AL4V ALLOY PRODUCED BY WIRE-FEED ELECTRON BEAM ADDITIVE MANUFACTURING | Zykova | Bulletin of the Siberian State Industrial University ВЛИЯНИЕ ТЕРМИЧЕСКОЙ ОБРАБОТКИ НА СТРУКТУРУ И СВОЙСТВА СПЛАВА ВТ6, ПОЛУЧЕННОГО ПРОВОЛОЧНОЙ ЭЛЕКТРОННО-ЛУЧЕВОЙ АДДИТИВНОЙ ТЕХНОЛОГИЕЙ | Зыкова | Вестник Сибирского государственного индустриального университета

Introduction. The relevance of this research is driven by the need to develop technologies for applying wear- and corrosion-resistant aluminum bronze coatings onto steel surfaces to reduce the weight and cost of components while maintaining their performance in aggressive environments such as seawater. Conventional deposition methods (e.g., brazing or electroplating) fail to provide sufficient adhesion and are unsuitable for tribological components, whereas high energy techniques require precise control of heat input and alloy composition to prevent defect formation and the development of brittle intermetallic phases. The purpose of this study is to investigate the effect of heat input during electron beam cladding on the formation of a CuAl9Mn2 alloy coating on stainless steel. Materials and methods. This study employed the method of electron beam cladding of single droplets onto a steel substrate under three operating modes with different electron beam current: 30, 45, and 60 mA, corresponding to heat inputs of 135, 202, and 270 J/mm. Metallographic examination, X ray diffraction analysis, energy dispersive X ray spectroscopy, and Vickers microhardness measurements were performed on the cross sections of the deposited droplets. Results and discussion. It was established that with increasing heat input, the dilution ratio of the bronze by the steel increases from 2% to 59%, the penetration depth increases from 0.06 mm to 2.43 mm, and the microhardness rises from 156 HV to 343 HV. At low heat inputs, epitaxial growth of α-Cu is observed along with the presence of β'-Cu3Al and γ-Cu9Al4 phases, indicating rapid cooling. At high heat inputs, intensive melt mixing, elemental diffusion, and the formation of iron containing inclusions occur, leading to the predominance of α-Cu, α-Fe, and γ-Fe phases and the suppression of the brittle γ phase. The obtained results demonstrate that controlled dilution during electron beam cladding can be utilized for targeted alloying and strengthening of bronze coatings, ensuring high adhesion and improved mechanical properties without the formation of defects typical of other cladding methods.

A multilayer material between Ti–6Al–4V–2Zr–2Mo and Inconel-625 was fabricated by WAAM. Scanning electron microscopy and X-ray diffraction were used to establish the following sequence of phase formation: γ+TCP → γ+TCP+η-Ni3Ti → γ+TCP+η-Ni3Ti+M6C → TCP+η-Ni3Ti+M6C+NiTi → η-Ni3Ti+M6C+NiTi+γ → Ti2Ni+Ti. The morphology of η-Ni3Ti changes from acicular to bulk-like depending on the local Ti/Al ratio under the thermal cycling conditions of WAAM. The maximum microhardness reaches ~8 GPa in regions enriched in η-Ni3Ti and TCP phases. The obtained results demonstrate the possibility of controlling the phase composition and properties of the transition zone through controlled chemical composition.

FEATURES OF FORMING BOUNDARIES OF BIMETALLIC SAMPLES BASED ON VARIOUS TYPES OF STEELS PRODUCED BY WIRE ELECTRON BEAM ADDITIVE MANUFACTURING | Gurianov | Bulletin of the Siberian State Industrial University ОСОБЕННОСТИ ФОРМИРОВАНИЯ ГРАНИЦ БИМЕТАЛЛИЧЕСКИХ ОБРАЗЦОВ НА ОСНОВЕ СТАЛЕЙ РАЗЛИЧНОГО ТИПА, ПОЛУЧЕННЫХ ПРОВОЛОЧНЫМ ЭЛЕКТРОННО-ЛУЧЕВЫМ АДДИТИВНЫМ ПРОИЗВОДСТВОМ | Гурьянов | Вестник Сибирского государственного индустриального университета

GRAIN STRUCTURE CONTROL OF TITANIUM ALLOYS PRODUCED BY WIRE-FEED ELECTRON BEAM ADDITIVE MANUFACTURING USING ULTRASONIC INDUCTION | Osipovich | Bulletin of the Siberian State Industrial University УПРАВЛЕНИЕ ЗЕРЕННОЙ СТРУКТУРОЙ ТИТАНОВЫХ СПЛАВОВ, ПОЛУЧАЕМЫХ МЕТОДОМ ПРОВОЛОЧНОЙ ЭЛЕКТРОННО-ЛУЧЕВОЙ АДДИТИВНОЙ ТЕХНОЛОГИИ ПРИ ИСПОЛЬЗОВАНИИ УЛЬТРАЗВУКОВОГО ВОЗДЕЙСТВИЯ | Осипович | Вестник Сибирского государственного индустриального университета

Ti4Al3V-Fe alloys have been obtained using wire and electron beam additive manufacturing that contained 1.7, 2.5 and 7.5 wt.% Fe. The first two alloys were composed of α/β lath structures, the third one was a fully β-Ti alloy reinforced by isothermal -Ti precipitates. Compression testing demonstrated TRIP behavior on the Ti4Al3V-7.5Fe alloys, which allowed achieving a combination of higher hardness with higher plasticity. This TRIP effect was due to β transformation under plastic deformation by dislocation slip. Such a combination of properties provided better wear resistance in rubbing against a steel counterpart. Layered Al2O3/TiO structures were observed in tribological layers of all sampl

Introduction. One of the most promising fields for the application of magnesium alloys is medicine. Their key advantages are bioresorbability and a low elastic modulus, comparable to that of human cortical bone (up to 30 GPa). Biocompatible Mg-Zn-Zr-Ce (MA20) system alloys are among the most promising for medical applications. Due to their relatively low mechanical properties, the development of severe plastic deformation (SPD) techniques for forming an ultrafine-grained (UFG) state in bulk billets of the Mg-Zn-Zr-Ce alloy to achieve optimal functional properties requires further research. Analyzing the conditions for forming a high-strength UFG state necessitates considering various strengthening mechanisms, including well-known ones related to the effect of UFG structures. Identifying the deformation and strain hardening mechanisms in magnesium alloys subjected to SPD is also highly relevant. The purpose of this work is to establish the mechanisms of strain hardening and to investigate the influence of heat treatment on the structure and properties of the MA20 magnesium alloy after combined SPD. Research methods. The study object was the MA20 alloy in a UFG state (wt. %: Mg – 98.0; Zn – 1.3; Ce – 0.1; Zr – 0.1; O – 0.5). The UFG state was achieved via a combined SPD process involving ABC-pressing followed by multi-pass rolling in grooved rolls. To study the effect of annealing on the microstructure and mechanical tensile properties, samples were annealed in air at temperatures of 200, 250, 300, and 500 °C for 24 hours. The microstructure and phase composition of the samples were investigated using optical and transmission electron microscopy. Results and discussion. It was established that applying a combined SPD method (ABC-pressing and multi-pass rolling) to the MA20 alloy results in the formation of an ultrafine-grained structure with an average grain size of about 1 μm. This leads to a significant increase in yield strength (σ0.2) to 250 MPa and ultimate tensile strength (σu) to 270 MPa, while simultaneously reducing ductility to 3%. Annealing at 200 °C was found to preserve the UFG state in the MA20 alloy and to lead to a 100% increase in ductility, with an 8% decrease in σ0.2 and a 4% decrease in σu compared to the initial UFG state (non-annealed). Conclusions. It was revealed that the grain boundary (σgrain = 202 MPa) and dislocation (σdis = 69 MPa) strengthening contributions provide the most significant increase in the strength of the UFG MA20 magnesium alloy. For the magnesium alloy in the UFG and fine-grained (FG) states, a critical grain size interval of (1–7) μm was identified, corresponding to a sharp increase in the intensity of change for the calculated contributions of dislocation (dσdis/ dd), grain boundary (dσgrain/ dd), overall strengthening (dσtotal/dd), and dislocation density (dρ/dd). For the coarse-grained (CG) state of the alloy in the grain size range (7–40) μm, these parameters stabilize.