No abstract

Three types of sintered alloys were fabricated based on cobalt, nickel and high-temperature alloy ZhS32-VI matrix with titanium carbide strengthening phase. TiC content was in a range of 30–50 vol. %. The melting temperatures of alloys are higher than 1320°C, and they may undergo undamaged through all technological procedures together with turbine blades, including soldering and outgassing. DSC analyses indicates no additional thermal effects until melting, which confirms their structural stability. The examinations of microstructure revealed three types of constituents – TiC particles, matrix solid solution and blow outs – structural defects having negative effects on all the studied properties. It was found that heat resistance of nickel based sintered alloys at the temperature of 1100°C is superior as compared with the alloys based on cobalt and alloy ZhS32-VI. It has been established that wear resistance in conditions of fretting wear at temperatures of 20, 850, 950 and 1050°C of sintered alloy with ZhS32-VI matrix is mostly superior as compared with the other alloys. The properties of produced alloys allow to use them for manufacturing of components of friction couples operating in conditions of high temperature fretting wear, including protective pads of turbine blades top shrouds contact faces.

Оттиски доступны непосредственно от издателя Фотокопирование разрешено только в соответствии с лицензией 2015 ИМФ (Институт металлофизики им. Г. В. Курдюмова НАН Украины) Напечатано в Украине.

No abstract

No abstract

The fusion diagram of the Al-CoW system in the Co-CoAl-W part was drawn using optical light, differential thermal, X-ray diffraction and electron microprobe analysis data. The alloys were prepared by arc melting. No ternary intermediate phase was found in this partial system above 900°C. The phase equilibria between CoAl and W were established with the peritectic reaction L+W↔CoAl at 1650ºC. The Co-CoAl-W fusion diagram has two isothermal three-phase fields corresponding to four-phase invariant reactions with participation of liquid: L↔Co+ + + +CoAl+ + + +Co 7 W 6 (1380°C) and L+ + + +W↔Co 7 W 6 + + + +CoAl (1490°C). The solidus and liquidus surface projections and the vertical sections for 75 at.% Co and equiatomic Al and W are presented and compared with the isothermal sections at 1200°C and 900°C reported earlier.

No abstract

669.017.13.1′293′295 Microstructure analysis, differential thermal analysis, x-ray diffraction, and electron probe microanalysis have been applied to the phase equilibria in the Fe − Nb − Ti ternary system over the complete composition range. The 950°C isothermal section of the diagram has been constructed. Positions have been determined for the monovariant transformation lines in the melting diagram. No ternary intermetallides have been found.