Wire-feed Electron Beam Additive Manufacturing Research Articles

INTERLAYER EFFECT ON DEFORMATION AND FRACTURE OF DENDRITIC STRUCTURE FORMED DURING WIRE-FEED ELECTRON-BEAM ADDITIVE MANUFACTURING OF AL-SI ALLOY

Interfaces and surfaces play an important role in tribology, mechanics and materials science, causing plastic strain localization and stress concentration of different spatial scales. The interfacial inhomogeneity is highly pronounced in 3D printed materials due to thermo-cycling and layer-by-layer building. In this paper, the inlayer and interlayer structure of a eutectic Al-Si alloy fabricated by wire-feed electron-beam additive manufacturing is investigated by optical and electron microscopy. Model structures inheriting the experimental morphology are created, and their deformation and fracture are simulated using ABACUS/Explicit, with the user-defined subroutines being developed to describe the constitutive behavior of aluminum dendrite, silicon and eutectic materials. A two-scale computational approach is implemented to study the influence of the interlayer formed in the heat-affected zone on the dendritic structure strength.

Коррозионные характеристики композитов БрАМц9-2/06Х18Н9Т, полученных двухпроволочным электронно-лучевым аддитивным производством

Introduction. The development of novel materials based on copper alloys and stainless steel, as well as the determination of the optimal parameters for its processing make it possible to expand the area of its implementation, increase efficiency and service life of tools and constructions. The load-bearing parts of marine equipment (bearing constructions, piston cylinders, pumps, valves, gears, rotary instruments, etc.), made of austenitic steels or aluminum bronze, are in direct contact with sea water, so the problem of increasing its corrosion resistance in the presence of strong oxidizing agents (Cl-, F- anions) is relevant. One of the advanced and actively researched methods for producing copper/steel composites is additive manufacturing that allow fabricating complex parts through layer-by-layer growth. In particular, the synthesis of composites based on aluminum bronze and steel can be realized by wire-feed electron beam additive manufacturing. In order to implement composite materials produced via additive technologies in a humid (marine) climate, it is necessary to ensure not only high strength, but also corrosion properties. The purpose of this work is to study the corrosion resistance of composites, based on aluminum bronze CuAl9Mn2 and stainless steel ER 321 produced by dual-wire-feed electron beam additive manufacturing. Research methods. Examination of the surface of CuAl9Mn2/ER 321 composites before and after corrosion tests was carried out by methods of voltammetry and electrochemical impedance spectroscopy using a potentiostat-galvanostat. Results and discussion. Using a complex of electrochemical methods, it is revealed that the developed composites with a volume fraction of steel ≥ 25% demonstrate a significant decrease in anodic current densities and a simultaneous increase in charge transfer resistance. Composites with a steel content of 75 vol. % are characterized by the highest corrosion properties in 3.5 wt. % NaCl solution, which is referred to a reduction in corrosion rate by 9.5 times compared to aluminum bronze. It is shown that the main processes occurring on the surface of the composites (CuAl9Mn2 + ER 321) are anodic oxidation of copper and iron, leading to the formation of corrosion products – Cu2O and FeCl2.

Effect of Annealing on the Microstructure, Phase Composition and Microhardness of the Ni–Ti Alloy Produced by Wire-Feed Electron-Beam Additive Manufacturing

Effect of Annealing on the Microstructure, Phase Composition and Microhardness of the Ni–Ti Alloy Produced by Wire-Feed Electron-Beam Additive Manufacturing

The Regularities of Metal Transfer by a Nickel-Based Superalloy Tool during Friction Stir Processing of a Titanium Alloy Produced by Wire-Feed Electron Beam Additive Manufacturing

In this work, the interaction of an additively produced Ti-4Al-3V titanium alloy with a nickel superalloy tool and the features of the stir zone formation during friction stir processing have been studied. The stop-action technique was used to produce the samples to be studied using optical and scanning electron microscopy methods, as well as microhardness measurements. As a result, it was revealed that the tool, when moving, forms a pre-deformed area in front of it, which is characterized by a fine-grained structure. The presence of an interface layer between the workpiece material and primary fragmentation by the tool was revealed. It was demonstrated that the transfer of titanium alloy material occurs periodically following the ratio of feeding speed to tool rotation rate. Metal flow around the tool can occur in both laminar and vortex modes, as indicated by the tool material stirred into the transfer layer and used as a marker.

Модуль упругости и твердость титанового сплава, сформировавшегося в условиях электронного лучевого сплавления при 3D-печати проволокой

Introduction. The development and application of additive manufacturing depends on many factors, including the printing process performance and buy-to-fly ratio. Wire-feed electron-beam additive manufacturing (EBAM) is attracting more and more attention from research teams. Moreover, the use of electron beams is the most effective and competitive for additive manufacturing of parts from alloys possessing high oxidation characteristics, e.g., titanium, stainless steels, since selective laser melting occurs in vacuum. Welding titanium wire VT6sv is the most preferable choice due to its availability and a wide range of thickness. This alloy, however, has fewer alloying elements than VT6 (Ti–6Al–4V) alloys. The high performance of wire-feed 3D printing and the VT6sv alloy composition affect the structure, phase composition, and properties of the fabricated alloy. As is known, the elastic modulus and hardness of alloys are important parameters, which can be measured rapidly also using non-destructive testing. The purpose of this work is to study the application of different approaches to measuring the elastic modulus and hardness of products obtained by wire-feed EBAM using the equipment of the Institute of Strength Physics and Materials Science SB RAS. Research methods. The structure of VT6sv titanium alloys fabricated by 3D printing and VT1-0 (Grade 2), VT6 (Ti–6Al–4V) alloys, was investigated by different methods such as metallography, ultrasonic gauging, instrumented indentation technique, macro- and micro-indentation, indentation hardness testing. Results and Discussion. Titanium alloy fabricated from VT6sv titanium wire under different thermal conditions has a typical columnar structure throughout the forging height. The structure formation determines the elastic modulus and hardness at various points of the forging. It is found that the elastic modulus is higher than that of as-delivered Ti–6Al–4V alloys, while the hardness is lower. Micro-indentation shows lower values of the elastic modulus than macro-indentation, which approach to values obtained by ultrasonic gauging and in other works. Different values of the elastic modulus at different points of the 3D printed forging indicate its sensitivity to the structure and phase composition of the material and demonstrate capabilities of measuring techniques used in this work.

Comparative Analysis of Weld Microstructure in Ti-6Al-4V Samples Produced by Rolling and Wire-Feed Electron Beam Additive Manufacturing

The microstructure and phase composition of electron beam welded Ti-6Al-4V titanium alloy were studied by optical and scanning electron microscopy, backscattered electron diffraction, and X-ray diffraction analysis. Deep-penetration electron beam welds were made in a single pass on rectangular Ti-6Al-4V samples obtained by rolling and wire-feed electron beam additive manufacturing. It was found that the weld width in the 3D printed Ti-6Al-4V samples is greater than in the rolled material. The influence of the vapor capillary on the size, shape and structure of primary β grains formed in the fusion zone was shown. The variation of the penetration coefficient, volume fraction of the residual β phase, and residual stresses along the weld length was studied for Ti-6Al-4V samples obtained by both rolling and 3D printing.

Formation of Defects and Inhomogeneities in the Structure of Composite Materials Based on Aluminum-Manganese Bronze with an In Situ Introduction of Nickel and Titanium Alloys or Steel During Wire-Feed Electron Beam Additive Manufacturing

Formation of Defects and Inhomogeneities in the Structure of Composite Materials Based on Aluminum-Manganese Bronze with an In Situ Introduction of Nickel and Titanium Alloys or Steel During Wire-Feed Electron Beam Additive Manufacturing

Structure Formation of Composite Material Based on Ferrite-Pearlite Steel and Aluminum Bronze Produced by Wire-Feed Electron Beam Additive Manufacturing

Structure Formation of Composite Material Based on Ferrite-Pearlite Steel and Aluminum Bronze Produced by Wire-Feed Electron Beam Additive Manufacturing

Regularities of Structure Formation of Composite Materials Based on Ferrite-Pearlite Steel and Aluminum-Manganese Bronze by Wire-Feed Electron Beam Additive Manufacturing

Regularities of Structure Formation of Composite Materials Based on Ferrite-Pearlite Steel and Aluminum-Manganese Bronze by Wire-Feed Electron Beam Additive Manufacturing

The Effect of Interface Orientation During Uniaxial Tension of Functionally Gradient Materials of a Stainless Steel-Copper System Formed by the Wire-Feed Electron Beam Additive Manufacturing

The Effect of Interface Orientation During Uniaxial Tension of Functionally Gradient Materials of a Stainless Steel-Copper System Formed by the Wire-Feed Electron Beam Additive Manufacturing

A Study of Deformation and Fracture of the Eutectic in an Additively Manufactured Al-Si Composite Alloy

Experimental and numerical studies were conducted on AlSi12 alloy fabricated by wire-feed electron beam additive manufacturing to examine the structure, thermomechanical behavior and fracture of a eutectic microvolume at the scale of several microns. Dynamic boundary value problems were solved under plane strain conditions. The composite structure of the eutectic phase consisting of an aluminum matrix and silicon particles was taken into account explicitly in the calculations. Isotropic models of the thermoelastoplastic matrix and elastic-brittle particles were implemented in ABAQUS/Explicit. Composite deformation was calculated both with and without allowance for residual stresses caused by cooling of the composite after its fabrication. It was shown that after the cooling of the eutectic, silicon particles are compressed, and the aluminum matrix is under both bulk compressive and tensile as well as under pure shear stresses. It was found that residual stresses play a negative role at the stages of intense deformation of the composite. The fracture strain of the eutectic strongly depends on the yield point of the matrix, while the ultimate fracture stress varies but only slightly. Favorable morphology of silicon particles was determined which prevents early fracture of the eutectic.

Macro- and Microstructural Homogeneity of Nickel-Based Superalloy Product Material Obtained by Wire-Feed Electron Beam Additive Manufacturing

This paper investigates the structural homogeneity of samples of articles made of ZhS6U alloy obtained by wire-feed electron beam additive technology. It is found that the formed material is represented by directionally growing dendrites and does not contain any defects. The temperature gradient value and its dependence on the height of the additively formed product are estimated using the change in the primary dendrite arm spacing. On this basis, it is concluded that the temperature gradient values achieved during the additional formation process correspond to the modern methods of directional solidification. The features of the electron-beam additive process that affect the heat removal conditions and cause changes in the temperature gradient are shown. It is found that changes in these conditions do not significantly affect the size and morphology of the intermetallic γ'-phase. It is demonstrated that the mechanical properties of the additively formed product material are superior to those of the original material in the as-cast state.

On the Control of Elemental Composition, Macro-, and Microstructure of Directionally Solidified Additive Products from Nickel-Based Alloy

The present work establishes the influence of heat input and methods of heat removal at the wire-feed electron beam additive manufacturing (EBAM) process on the structure of an additive product made of a nickel-based alloy. The following printing approaches are considered: changes in heat input, 3D printing strategy, and heat removal conditions due to (1) heating of the substrate, (2) partial suppression of radiative heat dissipation, and (3) thermal insulation of the substrate. It is shown that epitaxial growth of dendrites occurs in each case. However, in the case of an increase in speed and a change in the 3D printing strategy, the directed dendritic growth is interrupted. Preheating of the substrate and subsequent maintenance of the temperature reached during the EBAM process, as well as partial suppression of the radiative component of heat removal, allow to obtain the most uniform directional structure.

Microstructure, Phase Composition, and Microhardness of the NiCr/Al Gradient Material Produced by Wire-Feed Electron-Beam Additive Manufacturing

Microstructure, Phase Composition, and Microhardness of the NiCr/Al Gradient Material Produced by Wire-Feed Electron-Beam Additive Manufacturing

Effect of heat input on the microstructure and mechanical properties of Ti–6Al–4V alloy repaired by wire-feed electron beam additive manufacturing

Wire-feed electron beam additive manufacturing (WFEBAM) was utilized to repair the damaged Ti6Al4V (abbreviated as Ti64) alloy with B and Y modified Ti64 wire, and the effect of heat input on the repaired microstructure and properties of Ti64 alloy was investigated. The results indicated that the sizes of prior columnar β grains and α laths increased gradually with increased heat input. Besides the fine acicular α laths, continuous αGB, and retained β phase, bits of needle-like TiB and Y2O3 nanoparticles were formed in the deposited zone (DZ) due to the addition of B and Y elements in Ti64 wire. In addition, the increased heat input reduced the microhardness and wear resistance of the DZ, while still being superior to the mechanical properties of Ti64 substrate. It is attributed to the refinement of α laths and precipitates. Compared with Ti64 substrate, the DZ in as-repaired sample 1# with the lowest heat input (288 J/mm) showed the maximum microhardness (386HV), 18% higher than that of Ti64 substrate. While the DZ 1# also obtained the lowest friction coefficient (0.49), about 80.3% of Ti64 substrate. The tensile strength and elongation of the DZ 1# were 840.6 MPa and 14%, respectively, both of which remained above 88% of Ti64 substrate. Therefore, the as-repaired sample 1# with the lowest heat input could meet the repair requirements.

Al-Al3Ni In Situ Composite Formation by Wire-Feed Electron-Beam Additive Manufacturing.

The regularities of microstructure formation in samples of multiphase composites obtained by additive electron beam manufacturing on the basis of aluminum alloy ER4043 and nickel superalloy Udimet-500 have been studied. The results of the structure study show that a multicomponent structure is formed in the samples with the presence of Cr23C6 carbides, solid solutions based on aluminum -Al or silicon -Si, eutectics along the boundaries of dendrites, intermetallic phases Al3Ni, AlNi3, Al75Co22Ni3, and Al5Co, as well as carbides of complex composition AlCCr, Al8SiC7, of a different morphology. The formation of a number of intermetallic phases present in local areas of the samples was also distinguished. A large amount of solid phases leads to the formation of a material with high hardness and low ductility. The fracture of composite specimens under tension and compression is brittle, without revealing the stage of plastic flow. Tensile strength values are significantly reduced from the initial 142-164 MPa to 55-123 MPa. In compression, the tensile strength values increase to 490-570 MPa and 905-1200 MPa with the introduction of 5% and 10% nickel superalloy, respectively. An increase in the hardness and compressive strength of the surface layers results in an increase in the wear resistance of the specimens and a decrease in the coefficient of friction.

Influence of the Coarse Grain Structure of a Titanium Alloy Ti-4Al-3V Formed by Wire-Feed Electron Beam Additive Manufacturing on Strain Inhomogeneities and Fracture.

In this work, based on the multilevel approach, the features of the structure and properties of titanium alloy, formed during high-performance additive manufacturing by wire-feed electron beam technology, were studied. Methods of non-destructive X-ray control and tomography, along with optical and scanning electron microscopy, were used to study the structure at different scale levels of the sample material. The mechanical properties of the material under stress were revealed via the simultaneous observation of the peculiarities of deformation development, using a Vic 3D laser scanning unit. Using microstructural and macrostructural data, as well as fractography, the interrelations of structure and material properties caused by the technological features of the printing process and the composition of used welding wire were revealed.

Transformations of the Microstructure and Phase Compositions of Titanium Alloys during Ultrasonic Impact Treatment Part III: Combination with Electrospark Alloying Applied to Additively Manufactured Ti-6Al-4V Titanium Alloy

Scanning electron microscopy, 3D optical surface profilometry, as well as X-ray diffraction and electron backscatter diffraction analysis were implemented for studying the effects of both ultrasonic impact treatment (UIT) and ultrasonic impact electrospark treatment (UIET) procedures on the microstructure, phase composition, as well as the mechanical and tribological properties of Ti-6Al-4V samples fabricated by wire-feed electron beam additive manufacturing. It was shown that he UIET procedure with the WC-6%Co striker enabled to deposit the ~10 µm thick coating, which consists of fine grains of both tungsten and titanium-tungsten carbides, as well as titanium oxide. For the UIET process, the effect of shielding gas on the studied parameters was demonstrated. It was found that the UIET procedure in argon resulted in the formation of a dense, continuous and thick (~20 µm) coating. After the UIET procedures in air and argon, the microhardness levels were 26 and 16 GPa, respectively. After tribological tests, wear track surfaces were examined on the as-built sample, as well as the ones subjected to the UIT and UIET procedures. It was shown that the coating formed during UIET in air had twice the wear resistance compared to the coating formed in argon. The evidence showed that the multiple impact of a WC-Co striker with simultaneous electrical discharges was an effective way to improve wear resistance of the Ti-6Al-4V sample.

Wire-Feed Electron Beam Additive Manufacturing: A Review

The work is devoted to a review of modern achievements in the field of wire-feed electron beam additive manufacturing. The features of structure formation in aluminum, copper, titanium, nickel-based alloys, and steels during 3D printing are shown. Aspects of directional solidification during the production of components from various metals and alloys are considered. The prospects for obtaining composite and functionally graded materials based on various metals and alloys using wire-feed electron beam additive manufacturing are determined. The regularities of the structure modification and hardening of additively manufactured materials by the method of friction stir processing were considered. The main purpose of the review is to present additive manufacturing methods, the main focus being on the wire-feed electron beam additive manufacturing of metal alloys.

A STUDY OF DEFORMATION AND FRACTURE OF THE EUTECTIC IN AN ADDITIVELY MANUFACTURED AL-SI COMPOSITE ALLOY

The structure of AlSi12 alloy fabricated by wire-feed electron beam additive manufacturing was studied experimentally. A numerical study was performed to examine the thermomechanical behavior and fracture of a eutectic fragment at the scale of several microns. Boundary dynamic problems were solved under plane strain conditions. The composite structure of the eutectic system consisting of an aluminum matrix and silicon particles was taken into account explicitly in the calculations. Isotropic models of the thermoelastic-plastic matrix and elastic-brittle particles were implemented in ABAQUS/Explicit. Strains in the composite were calculated both with and without allowance for residual stresses caused by cooling after fabrication. It was shown that after the cooling of the eutectic, silicon particles are compressed, and the aluminum matrix is under both bulk compressive and tensile as well as under pure shear stresses. It was found that residual stresses play a negative role at the stages of intense deformation of the composite. The fracture strain of the eutectic strongly depends on the yield stress of the matrix, while the ultimate fracture stress varies little. Favorable morphology of silicon particles was determined which prevents early fracture of the eutectic.