1. Development of selective laser melting parameters for epitaxial crystal growth

Авторы:
BORISOV Evgenii, SUFIIAROV Vadim, POLOZOV Igor, MASAYLO Dmitriy

Аннотация:
Parts from heat-resistant nickel alloys with directional crystallization, as well as single crystals are used in engines and power plants operating under conditions of high temperatures and loads. In this paper, the study of the structure formation in the process of selective laser melting of a heat-resistant nickel alloy was conducted. It is obtained that the length of the forming grains considerably exceeds the thickness of one build layer. The results of the influence of the technological parameters of the selective laser melting process on the directionally crystallised structure characteristics are shown. Elongated grains oriented along the growth direction. The composition, structure, and properties of the obtained samples were studied.

Скачать

1. Gamma-Titanium Intermetallic Alloy produced by Selective Laser Melting using Mechanically Alloyed and Plasma Spheroidized Powders

Авторы:
Igor Polozov¹, Vera Popovich^{1, 2}, Nikolay Razumov¹, Tagir Makhmutov¹, Anatoliy A. Popovich¹

Аннотация:
Conventional manufacturing of titanium intermetallic alloys is associated with brittleness, hard machinability and, consequently, the high cost, which makes additive manufacturing a promising way of producing complex intermetallic parts. At the same time, γ-TiAl alloys exhibit good high temperature strength, fatigue and oxidation resistance. In the present study the gamma-based alloy spherical powders were prepared by mechanical alloying from elemental powders followed by the plasma spheroidization process. Microstructure and phase composition of the produced powders were studied after different milling times in a planetary mill. The optimally milled powders were treated in the flow of a thermal plasma to obtain powder particles with a high degree of sphericity. The produced spherical powders were used in Selective Laser Melting (SLM) process with high preheating temperatures to obtain crack-free intermetallic samples. The microstructure and phase composition of the SLM-ed TiAl-samples were investigated with regard to different process parameters.

Скачать

2. Synthesis of TI48AL2CR2NB intermetallic alloy powder for additive manufacturing by mechanical alloying and plasma spheroidization

Авторы:
¹Igor POLOZOV, ¹Tagir MAKHMUTOV, ¹Nikolay RAZUMOV, ¹Artem KIM, ¹Nikolay OZERSKOI, ¹Anatoliy A. Popovich

Аннотация:
In this paper, Ti-48Al-2Cr-2Nb (at. %) gamma-based alloy spherical powders were prepared by mechanical alloying of elemental powders and plasma spheroidization. Microstructural features and phase composition of the obtained powders were studied after different time of mechanical alloying in a planetary mill to investigate the alloy formation. After determining optimal milling parameters allowing to obtain powders with a fairly homogeneous microstructure and composition, the powders were treated in the flow of a thermal plasma to produce powder particles with a high degree of sphericity. The produced spherical powders were investigated using Scanning Electron Microscopy and X-Ray Diffraction. The study showed the feasibility of the suggested approach to fabricate spherical homogeneous powders of gamma-based intermetallic alloy for its application in Additive Manufacturing processes.

Скачать

3. Selective laser melting for nb-based powder alloy

Авторы:
¹Ivan GONCHAROV, ¹Nikolay RAZUMOV, ¹Evgenii BORISOV, ¹Aleksey SILIN, ¹Anatoliy A. Popovich

Аннотация:
The powder of Nb-25Ti-2Cr-2Al-16Si (at.%) was obtained by mechanical alloying and plasma spheroidization from elemental powders. The building was performed by SLM 280HL machine on the titanium substrate. The microstructure was analyzed by MIRA Tescan scanning electronic microscope. The XRD was performed by BRUKER D8. The microstructure consists of Nbss+Nb3Si eutectic with several areas of coarse dendrites, corresponds to the Nbss. The microstructure is greatly refined in comparison with casting technologies like VIM.

Скачать

1. Numerical simulation of temperature distribution and material flow during friction stir welding of magnesium alloy

Авторы:
Evgenii N. Rylkov¹, Anton A. Naumov¹, Fedor Yu. Isupov¹, Oleg V. Panchenko¹, Anatoliy A. Popovich¹

Аннотация:
Magnesium alloys are widely used in aerospace industries and are very prospective to use in automotive industry, but the joining of Mg-based alloys by means of fusion welding techniques causes a number of difficulties. The solid-state joining techniques, such as friction stir welding (FSW), can be successfully used to join this type of alloys.
In the present research parameters of FSW are selected to produce defect-free joints, the CFD modeling was used to describe the temperature field and material flow during FSW of magnesium alloy. Developed model was used to determine the temperature field and material flow around the tool.

Скачать

2. Numerical simulation of the selective laser melting process using the example of a turbine blade

Авторы:
Aleksei Orlov^{1, a}, Evgenii Borisov¹  and Anatoliy A. Popovich¹

Аннотация:
Additive manufacturing is widespread in the modern world. Many foreign companies are moving to mass production of parts using additive technologies. To reduce the risks associated with the building up parts it is necessary to use numerical methods for predicting the deformation and internal quenching stresses and to optimize the support structures of parts. In this work, it was simulated the process of selective laser melting in the Amphyon software package to predict internal quenching stresses and strains using the example of a gas turbine engine blade. The calculation results are presented and the deformed as well as the pre-deformed models are presented.

Скачать