MATERIALS SCIENCE | |
Название | High temperature synthesis of nickel aluminide alloys with tungsten carbide |
DOI | 10.17580/nfm.2020.01.05 |
Автор | Khimukhin S. N., Deev V. B., Ri E. Kh., Kim E. D. |
Информация об авторе | Institute for Materials Technology, Khabarovsk Research Centre at the Far Eastern Branch of the Russian Academy of Sciences, Khabarovsk, Russia: S. N. Khimukhin, Professor, Head of the Laboratory for Structural and Tooling Materials, e-mail: ximyxin@yandex.ru Wuhan Textile University, Wuhan, China1 ; National University of Science and Technology “MISIS”, Moscow, Russia2:
Pacific National University, Khabarovsk, Russia: |
Реферат | Nickel aluminides of a composite structure, hardened by the inclusions of refractory transition metal compounds, have great potential in terms of creating new materials with the increased strength and heat resistance. The variety of compositions of alloying systems allows obtaining composite materials of different types with a complex of the improved operational characteristics. This work presents the research results of studying the synthesis conditions for metal matrix alloys from pure metal oxides. The microhardness, phase and element compositions of the resulting alloys have been investigated. It is found that composite alloys are formed in the result of thermally conjugated exothermic reactions in NiO – Al and WO3 – C – Al systems. Thermodynamic analysis shows that the probability of obtaining cast products in the result of such reactions is very high. The dominant reaction corresponds to the parameters: G = –944 kJ/mol, adiabatic temperature (AT = 3150 K. The influence of the synthesis conditions on the composition of the intermetallic phase of the composite has also been studied. The possibility of the formation of Ni2Al3 and NiAl intermetallic compounds is proved. It is established that in order to create optimal conditions for the formation of intermetallic compounds an excess amount of aluminum (~ 30 wt.%) in the total initial charge mixture is required. An increase of carbon in the composition of the initial charge mixture to ~ 20 wt.% raises the content of tungsten carbide in the synthesized alloy. In this case, a decrease in the temperature causes the formation of Ni2Al3 intermetallic phase. Composite materials are represented by NiAl and Ni2Al3 phases with WC tungsten carbide inclusions according to the results of elemental, X-ray phase analysis and scanning electron microscopy. The volumetric content of tungsten carbide in alloys is ~20%. The resulting alloys have the increased microhardness due to the inclusion of the refractory interstitial WC phase (8.5–9.8 GPa) in their structure. Composite materials based on NiAl are promising for application as heat-resistant coatings. The work was carried out within the project SP-1904.2019.1 “Development of an energy-saving technology for producing metal matrix composite materials from mineral concentrate (scheelite) for forming coatings with enhanced wear-resistant properties by ESA method on steel products” of the Federal Target Program “Scholarship of the President of the Russian Federation to young scientists and graduate students engaged in advanced research and development in priority areas of modernization of the Russian economy, for 2019–2021” with the financial support of the Ministry of Education and Science of the Russian Federation. |
Ключевые слова | Nickel aluminide, tungsten carbide, aluminothermy microstructure, microhardness, metal matrix alloy |
Библиографический список | 1. Gostishchev V., Ri E., Ri H., Kim E., Ermakov M., Khimukhin S., Deev V., Prusov E. Synthesis of Complex-Alloyed Nickel Aluminides from Oxide Compounds by Alumi-nothermic Method. Metals. 2018. Vol. 8, Iss. 6. DOI: 10.3390/met8060439 |
Полный текст статьи | High temperature synthesis of nickel aluminide alloys with tungsten carbide |