Intermetallic Coatings After Heat Resistance Test

Abstract

ИНТЕРМЕТАЛЛИДНЫЕ ПОКРЫТИЯ ПОСЛЕ ИСПЫТАНИЯ НА ЖАРОСТОЙКОСТЬИсследована структура интерметаллидных покрытий, сформированных методом электроис-крового легирования (ЭИЛ) на стали 30, после ис-пытания на жаростойкость при температуре 900 °С. В качестве материалов для покрытий использованы сплавы, полученные методом алюминотермии из оксидов. Методом микрорентгеноспектрального анализа на поперечных шлифах образцов стали с покрытиями изучен элементный состав различных структурных составляющих.Ключевые слова: алюминиды никеля, элек-троискровое легирование, композиционные покры-тия, жаростойкость.S.N. Khimukhin, V.V. Gostishchev, A.V. Medneva, Hosen Ri, E. H. Ri. INTERMETALLIC COATINGS AFTER HEAT RESISTANCE TESTThe structure of intermetallide coatings formed by a method of electro-spark alloying (ESA) is investigated on steel 30 after a test for heat-resistance at a temperature of 900ºC. As materials for coatings there were used alloys obtained from oxides by an alumothermy method. NiAl based alloys by Cr, Mo, W, separately and in complex. By a method of an electron microprobe analysis on cross microsections of samples of steel with coatings there was studied an element composition of different structural constituents. Maximum values of the mass transfer at the formation of coatings by material having NiAlCr are explained by presence in the structure of a softening phase containing an increased concentration of Cr (mass % 80-93). It is defined that the highest values of heat-resistance are ensured by a coating formed with the use of a complex doped alloy NiAl-Cr-Mo-W. A distinguishing feature of this coating is its fine structure and presense on borders of phases of structural constituents of alloying elements hindering diffusion.