Influences of Yttrium on Microstructure and Mechanical Properties of NiAl -28Cr-5.5Mo-0.5Hf Alloy
来源期刊:JOURNAL OF RARE EARTHS2002年第4期
论文作者:郭建亭 周继扬 任维丽
Key words:rare earths; NiAl alloy; microstructure; mechanical prop erties;
Abstract: The influences of yttrium on the microstructure and mechanical properties of NiA l-28Cr-5.5Mo-0.5Hf alloy were investigated by using SEM, XRD and compressive tests, respectively. The study indicates that the compressive strength and ducti lity of 0.05% Y(mass fraction)-containing alloy are superior to those of other alloys at the strain rate of 1.94×10-3 s-1 over a range from room t em perature to high temperature. It is also found that the microstructure of alloys is refined gradually with increasing Y content. This is reflected by more grain cells, finer spacing between Cr(Mo) fibers and smaller Cr(Mo) rods at the grain boundary. When 0.1% Y(mass fraction) and above are added to the matrix, the ytt rious compounds of Y2Ni17 and Al3Y form at the interfaces between NiAl and Cr(Mo) phases, which leads to the decrease of strength and ductility. Ther efore, the proper addition of Y can improve the compressive strength and ductili ty of the alloy.
郭建亭1,周继扬2,任维丽2
(1.Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China;
2.Department of aterials Engineering, Dalian University of Te chnology, Dalian 116024, China;
3. Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)
Abstract:The influences of yttrium on the microstructure and mechanical properties of NiA l-28Cr-5.5Mo-0.5Hf alloy were investigated by using SEM, XRD and compressive tests, respectively. The study indicates that the compressive strength and ducti lity of 0.05% Y(mass fraction)-containing alloy are superior to those of other alloys at the strain rate of 1.94×10-3 s-1 over a range from room t em perature to high temperature. It is also found that the microstructure of alloys is refined gradually with increasing Y content. This is reflected by more grain cells, finer spacing between Cr(Mo) fibers and smaller Cr(Mo) rods at the grain boundary. When 0.1% Y(mass fraction) and above are added to the matrix, the ytt rious compounds of Y2Ni17 and Al3Y form at the interfaces between NiAl and Cr(Mo) phases, which leads to the decrease of strength and ductility. Ther efore, the proper addition of Y can improve the compressive strength and ductili ty of the alloy.
Key words:rare earths; NiAl alloy; microstructure; mechanical prop erties;
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