Structure and properties of alloyed powders based on Fe₃Al intermetallic for thermal spraying produced using mechanochemical synthesis method

Abstract

Results of experimental studies of the influence of the ratio of static and dynamic stresses on limit stresses and second critical brittleness temperature of butt welded joints with a crack on 09G2 and 12GN2MFAYu steels under the conditions of room and low (to-80 °C) temperatures are analyzed. It is found that at the specified temperature the dynamic component of critical stress decreases linearly with increase of static stress. It is shown that decrease of limit stresses and increase of the second critical brittleness temperature take place at increase of the dynamic factor. Critical brittleness temperatures of welded joints of steel with higher mechanical properties are significantly lower. It is found that ignoring the dynamic stresses leads to underestimated values of limit stress and overestimated values of second critical brittleness temperature. Presented analysis of research allows a more substantiated approach to assessment of brittle fracture resistance of structural elements made from the studied materials, and determination of their safety margins. 7 Ref., 1 Table, 7 Figures.

Effect of APS Spraying Parameters on the Microstructure Formation of Fe3Al Intermetallics Coatings Using Mechanochemically Synthesized Nanocrystalline Fe-Al Powders

“…The characteristics of the MCS powders used in work for investigating the coating formation process during plasma spraying are shown in Table 2 [ 15 , 16 ].…”

“…At present, one of the ways to obtain composite intermetallic powders of the Fe-Al system for thermal spraying is the mechanochemical synthesis method (MCS) [ 15 , 16 , 17 ].…”

Characteristic Features of Structure and Analysis of Friction Behavior of Electric-Spark Coatings from Powder Wires

“…The physical-chemical processes occurring during the formation of particles of iron intermetallics based on Fe 3 Al alloyed with Cr, Zr, Mg, La, and Ti under conditions of mechanochemical synthesis were studied in works [16,17]. It was found that the mechanism of formation of both unalloyed Fe 3 Al particles and particles of alloyed powders based on this intermetallic compound consists of a number of successive stages: formation of conglomerates from a mixture of initial Fe powders and aluminum alloys; formation of solid solutions of alloying elements based on the Fe 3 Al lattice or an Al solid solution in the FeTi lattice; transformation of solid solutions into single-phase products Fe 3 Al(Cr,Zr), Fe 3 Al(Mg), Fe 3 Al(Mg,La) and (Fe,Ti) 3 Al with nanodispersed structure (coherent scattering region 10-30 nm).…”