K problematice fázové struktury a vysokoteplotních mechanických vlastností aluminidů na bázi FeAl a Fe3Al v přítomnosti aditiv
Loading...
Date
2016
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Předkládaná habilitační práce představuje průřez výzkumem vlivu fázového sloţení na
vysokoteplotní vlastnosti aluminidů ţeleza s aditivy. Dlouhodobým cílem je uvést do praxe
materiál na bázi aluminidu ţeleza s dobrou vysokoteplotní odolností a vyrobený klasickou
technologií.
Výzkum slitin s FeAl matricí s aditivy uhlíkem a křemíkem je historicky inspirován slitinami
typu Pyroferal, vyvinutými v československu v padesátých letech minulého století. Ve
slitinách s vyššími obsahy uhlíku byla potvrzena přítomnost karbidu Al4C3 ve struktuře slitin
dopovaných křemíkem i ve slitinách bez křemíku a bylo prokázáno, ţe tato fáze účinně brání
pohybu dislokací v matrici při vysokoteplotní deformaci.
Studium aluminidů ţeleza na bázi Fe3Al s přídavkem karbidotvorných prvků je zaměřeno na
aditiva či kombinace aditiv zvyšujících vysokoteplotní odolnost slitin. Byl ukázán význam
poměru legujících prvků Zr a C a stanoven jeho vliv na vysokoteplotní mechanické vlastnosti
a vysokoteplotní oxidační odolnost.
Fázové sloţení slitin bylo studováno moderními metodami strukturní a fázové analýzy jako je
elektronová mikroskopie, energiově disperzní analýza, rentgenová difrakce, případně difrakce
zpětně odraţených elektronů. Vliv fázového sloţení na vysokoteplotní mechanické vlastnosti
byl sledován prostřednictvím vysokoteplotních testů v tahu či tlaku a testů creepové
odolnosti.
The submitted habilitation thesis represents a profile in research of phase composition effect on high temperature properties of iron aluminides with additives. The long term goal is to put into practice a material based on iron aluminide with good high temperature resistance (and produced by traditional technology). The research of FeAl matrix alloys with additives carbon and silicon alloys is historically inspired by the Pyroferal alloys, developed here in the fifties of the last century. The presence of carbide Al4C3 was confirmed in the structure of alloys with higher carbon content doped by silicon and silicon-free. It has been shown that this phase effectively prevents the motion of dislocations in the matrix during the high temperature deformation. The investigation of Fe3Al-based iron aluminides with added carbid-forming elements is focused on additives or combinations of additives increasing the high temperature resistance of alloys. It was shown the importance of the ratio of the alloying elements Zr and C. The effect of this ratio on high temperature mechanical properties and high temperature oxidation resistance was described. The phase composition of alloys has been studied by modern methods of structural and phase analysis such as electron microscopy, energy dispersive analysis, X-ray diffraction, or electron backscatter diffraction. The influence of phase composition on high temperature mechanical properties was investigated by means of high-temperature tensile or pressure tests, and creep resistance tests.
The submitted habilitation thesis represents a profile in research of phase composition effect on high temperature properties of iron aluminides with additives. The long term goal is to put into practice a material based on iron aluminide with good high temperature resistance (and produced by traditional technology). The research of FeAl matrix alloys with additives carbon and silicon alloys is historically inspired by the Pyroferal alloys, developed here in the fifties of the last century. The presence of carbide Al4C3 was confirmed in the structure of alloys with higher carbon content doped by silicon and silicon-free. It has been shown that this phase effectively prevents the motion of dislocations in the matrix during the high temperature deformation. The investigation of Fe3Al-based iron aluminides with added carbid-forming elements is focused on additives or combinations of additives increasing the high temperature resistance of alloys. It was shown the importance of the ratio of the alloying elements Zr and C. The effect of this ratio on high temperature mechanical properties and high temperature oxidation resistance was described. The phase composition of alloys has been studied by modern methods of structural and phase analysis such as electron microscopy, energy dispersive analysis, X-ray diffraction, or electron backscatter diffraction. The influence of phase composition on high temperature mechanical properties was investigated by means of high-temperature tensile or pressure tests, and creep resistance tests.