Physical and Mechanical Properties of MoSi₂-Er₂Mo₃Si₄ Composites


A study has been conducted to determine the feasibility of using Er2Mo3Si4 as a reinforcement phase to improve the high temperature strength of MoSi2. The melting temperature of Er2Mo3Si4 was determined to be 1930±20 °C whereas the eutectic of Er2Mo3Si4-39 vol% MoSi2 melted at 1790±10 °C. Elevated temperature microhardness tests show that Er2Mo3Si4 has significantly higher hardness than MoSi2 above 1000 °C, e.g. approximately 5.8 GPa versus 1.5 GPa at 1300 °C, respectively. A MoSi2/Er2Mo3Si4/20 p composite was produced by ball milling and hot pressing arc-melted MoSi2-20 vol% Er2Mo3Si4 materials. At 1300 °C the MoSi2/Er2Mo3Si4/20 p composite and a directionally solidified Er2Mo3Si4-MoSi2 eutectic exhibited hardnesses of 2.4 GPa and 4 GPa, respectively. Preliminary results from compressive decremental step strain rate tests at 1300 °C indicate that the creep strength of the MoSi2/Er2Mo3Si4/20 p composite is comparable to that of a MoSi2/SiC/20 w composite. The creep stress exponent was determined to be 3.3 at 1200 °C and 3.7 at 1300 °C.

Meeting Name

Materials Research Society Symposium Proceedings (1993, Boston, MA, USA)


Materials Science and Engineering

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Article - Conference proceedings

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© 1993 Materials Research Society, All rights reserved.

Publication Date

01 Jan 1993