Control of microstructure and orientation distribution in Ni–Al-based (β/γ′) two phase alloys by thermomechanical processing
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- 作者：Sakata ; T. ; Yasuda ; H.Y. ; Umakoshi ; Y.
- 关键词：Intermetallic compounds ; Grain boundaries ; Texture ; Microstructure
- 刊名：Acta Materialia
- 出版年：2001
- 出版时间：December 3, 2001
- 年：2001
- 卷：49
- 期：2
- 页码：4231-4239
- 全文大小：469 K
文摘
Microstructure and orientation distribution of two phase Ni–Al(β)/Ni3Al(γ′) alloys obtained by thermomechanical processing were examined using electron back-scatter diffraction pattern technique. Cylindrical specimens were hot-compressed in the β phase region and subsequently annealed in the (β/γ′) two phase region. After the hot deformation, equiaxed β grains surrounded by high angle boundaries were homogeneously formed due to dynamic recrystallisation under adequate condition. Moreover, strong 
111
fibre texture parallel to the compressive axis developed in the β phase because of the lattice rotation during hot deformation. After annealing in the two phase region, γ′ phase transformed from β phase with 111β fibre texture satisfying the Kurdjumov–Sachs relationship and resulting in the formation of 110γ′ fibre texture. Film-shaped γ′ phase preferentially often precipitated along the β grain boundaries and a large number of (β/γ′) boundaries were partially coherent. This thermomechanical processing was effective in controlling the crystallography of γ′ along the β grain boundaries.
111 fibre texture parallel to the compressive axis developed in the β phase because of the lattice rotation during hot deformation. After annealing in the two phase region, γ′ phase transformed from β phase with 111β fibre texture satisfying the Kurdjumov–Sachs relationship and resulting in the formation of 110γ′ fibre texture. Film-shaped γ′ phase preferentially often precipitated along the β grain boundaries and a large number of (β/γ′) boundaries were partially coherent. This thermomechanical processing was effective in controlling the crystallography of γ′ along the β grain boundaries.