Reaction behavior and pore formation mechanism of TiAl-Nb porous alloys prepared by elemental powder metallurgy

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• 作者：Yongfeng Liang ; Fan Yang ; Laiqi Zhang ; Junpin Lin ; Shunli Shang ; Zi-Kui Liu
• 关键词：A. Titanium aluminides ; based on TiAl ; B. Phase transformation ; C. Powder metallurgy
• 刊名：Intermetallics
• 出版年：January, 2014
• 年：2014
• 卷：44
• 期：Complete
• 页码：1-7
• 全文大小：2739 K

文摘

Ti-48Al-6Nb (at.%) porous alloys are fabricated by elemental powder metallurgy to study the pore formation and propagation mechanism. Reactive diffusion, pore formation process, and pore characteristics of the porous TiAl-Nb alloys are investigated at different temperatures. It is found that the porous alloys exhibit a uniform, maze-like network skeleton, viz., a typical 伪₂-TiAl₃/纬-TiAl fully lamellar microstructure. The reactive diffusivities between Ti and Al powders are dominant during the Ti-Al-Nb powder sintering. Gas release during sintering also plays an important role in the pore propagation and the compact expanding process. In addition, a pore-formation model is proposed to interpret the growth mechanism of pores and skeletons.