Mechanically alloyed Mo-Si-B alloys with a continuous alpha-Mo matrix and improved mechanical properties

作者：Krueger M; Franz S; Saage H^*; Heilmaier M; Schneibel J H; Jehanno P; Boening M; Kestler H

来源：Intermetallics, 2008, 16(7): 933-941.

DOI：10.1016/j.intermet.2008.04.015

• molybdenum silicides
• brittleness and ductility
• mechanical alloying and milling
• microstructure
• aero-engine components

Mechanical alloying (MA) followed by cold isostatic pressing (CIPing), sintering and hot isostatic pressing (HIPing) was used to prepare Mo-base silicide alloys consisting of a Mo(Si) solid solution and the intermetallic phases Mo3Si and Mo5SiB2. The microstructural development during milling of both binary Mo-Si and Mo-B and ternary Mo-Si-B powder mixtures was evaluated. While obtaining a supersaturated solid solution requires rather long milling times, domain size (which correlates with the grain size) is reduced to below 100 angstrom after about 10 h of milling. After heat treatment and consolidation the microstructure reveals a continuous alpha-Mo matrix with embedded, uniformly distributed intermetallic particles. The establishment of such a microstructure is beneficial for the mechanical properties since, as compared to a discontinuous alpha-Mo matrix, it decreases the brittle-to-ductile transition temperature (BDTT) by about 150 K.

• 出版日期2008-7