【摘 要】
：
The ultrafine Mo-Y2O3 composite powders were successfully synthesized by innovative freeze-drying method.Consequently,the freeze-dried Mo-Y2O3 composite powders with high sintering activities pos-sess an average grain size of 54 nm.After low temperature s
【机 构】
：
Tianjin Key Laboratory of Composite and Functional Materials,School of Materials Science and Enginee
论文部分内容阅读
The ultrafine Mo-Y2O3 composite powders were successfully synthesized by innovative freeze-drying method.Consequently,the freeze-dried Mo-Y2O3 composite powders with high sintering activities pos-sess an average grain size of 54 nm.After low temperature sintering at 1600 ℃,the Mo-Y2O3 alloys maintaining a high density (99.6 ％) have the finest grain size (620 nm) comparing with available litera-ture about oxide dispersion strengthened molybdenum alloy (ODS-Mo).The oxide particles remain their small size (mainly ＜50 nm) within Mo grains and at Mo grain boundaries.Furthermore,the Y5Mo2O12 particles were firstly observed within Mo matrix,and its formation can absorb nearby oxygen impurities,which involves the purification of Mo matrix.The mechanical properties show that Mo-Y2O3 alloy pos-sess a high hardness of 487 ± 28 HV0.2,a high yield strength of 902 MPa,a high compressive strength of 1110 MPa,respectively.Our work suggests that freeze-drying and subsequent low temperature sintering can shed light on the preparation of ultrafine ODS-Mo alloys with high performance.
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