大晶粒Fe_3Al基合金的超塑性

SUPERPLASTICITY IN Fe_3Al ALLOY WITH LARGE GRAINS

本文研究了大晶粒Ｆｅ_３Ａｌ基合金Ｆｅ—２８Ａｌ—２Ｔｉ合金的高温变形行为。发现该合金在７５０℃到９００℃应变速率为１×１０^（－３）／ｓ时以及在８５０℃一个较宽的应变速率范围内具有超塑性，最佳延伸率可超过５００％。８５０℃不同应变速率下，ｍ值可以从０．２２变化到０．４１金相及ＴＥＭ观察表明变形过程中发生了明显的动态再结晶，并由此导致了大晶粒Ｆｅ_３Ａｌ合金中的超塑性。

High temperature deformation behaviour of Fe-28Al-2Ti alloy with large grains was examined. This alloy showed superplasticity in the temperature range of 750℃ to 900℃ under a strain rate of 1 × 10￣(-3)/ s and maintained superplastic it at 850℃ in a relatively wide range of strain rate. The highest m value may exceed 500%. At 850℃ . m value changes from 0.22 to 0.41 under different strain rates. Optical and TEM observations revealed that a dynamic recrystallization process took place with the deformation process and this in turn resulted in the superplasticity in this alloy with large grains