Research On High Temperature Comprassion Behaviors Of Ti45Al5Nb0.8Mo0.3Y Alloy

The TiAl alloys's excellent high temperature character,antioxidation character and its low density makes it have great application prospect in aerospace area. But its poor workability is one of the factors that limit its extensive use. There are mainly two methods to improve its workability: 1,Add alloying element to refine grain. 2,Form new phrase. This paper researches the extruded Ti45Al5Nb0.8Mo0.3Y alloy's high temperature compression behaviors through Gleebe1500 thermal simulation system,SEM,TEM and so on. The main research content includes:(1)Get the alloy's stress-strain curve at different condition after the thermal compress experiment at the Gleebe1500 thermal simulation system. The research illustrates the effect of temperature and strain rate on stress-strain curve. Draw the hot process windows map, and the alloy can be processed in abroad temperature and strain rate range through the map.(2)Watch the microstructure after the thermal simulation with the SEM and TEM, and analyze the effect of temperature and strain rate on the microstructure evolution.(3)Calculate the thermal activation energy and establish the hot deformation constitutive equations using the experiment data.(4)According the stress-strain curve at different temperature and strain rate, establish the hot processing map, and analyze systematically the effect of temperature and strain rate on power dissipative rate in the map, and study the grain evolution mechanism and recrystallization mechanism.