XING Liqian
,
CHEN Xichen
,
Institute of Physics
,
Academia Sinica
,
Beijing
,
ChinaYANG Gencang
,
ZHOU Yaohe
,
Northwestern Polytechnic University
,
Xi'an
,
ChinaGUO Zhenqi
,
Northwestern University
,
Xi'an
,
China XING Liqian
,
Postdoctoral
,
Institute of Physics
,
Academia Sinica
,
Beijing 100080
,
China
金属学报(英文版)
The glass formability of Ni_(75)B_(17)Si_8 melt and the thermostability of this metallic glass formed from the the melt can be enhanced by eliminating the heterogeneous catalystg. The purification was done by cyclical superheating melt in special glasses and subsequently cyclically superheating it in an electromagnetic levitation apparatus. The purified Ni_(75)B_(17)Si_8 amorphous sample sized up to 20 ~ I0 x 0.5 mm was prepared as four times the thickness of unpurified ones.
关键词:
metallic glass
,
null
,
null
,
null
YC. Liu
,
G.C. Yang
,
YL. Lu and Z.G. Zhu (State Key Lab. of Solidification Processing
,
Northwestern Polytechnic University
,
Xi'an 710072
,
China Laboratory of Internal Friction and Defects in Solids
,
Chinese Academy of Science
,
Hefei 230031
,
China )
金属学报(英文版)
The effects of cerium modification and extrusion on the resultant damping behavior and mechanical properties of the as-sprayed high silicon alloy ZA27 were investigated in an thort to develop a new functional material possessing high damping capacity and good mechanical properties. The damping capacity, as well as the rslative dynamic modulus, was tneasured at frequencies of 1 and 4 Hertz over the 30 to 200℃runge. At below 80℃ the as-sprayed materials appear to be approximately Asquency independent. Above 80℃, the,naterials becotne temperature sensitive, exhibiting the highest damping for the lowest hequency. The extruded, as-sprayed high silicon alloy ZA27 modified by cerium has the highest damping capacity and elongation values among them. The micro8tructure of the as-sprayed high silicon alloy ZA27 modified by 0. 5 wt% cerium was made up of fine lamellar eutectoid, porositg, a light dot-like phase and a polygonal silicon-rich phase. Finally, the opemtive damping tnechanisms were discussed in light of the data obtained hem characterization of microstructure and damping capacity. The high damping capacity was attributed primarily to phase interface thermoelastic damping between the lamellar phases with various substrvctures,except for the grain refinement.
关键词:
spray deposition
,
null
,
null
,
null
Yongchang LIU
,
Gencang YANG and Yili LU (State Key Lab. of Solidification Processing
,
Northwestern Polytechnic University
,
Xi'an 710072
,
China)Liushuan YANG(Dept. of Materials Science and Technology
,
Luoyang Institute of Technology
,
Luoyang 471039
,
China
材料科学技术（英）
High Al zinc-based alloys are widely used in industry for their good ambient temperature mechanical properties and damping capacity. With the rise of service temperature its damping property increases but mechanical property decreases greatly Here two ways-alloying and spray deposition technique were adopted to improve the service temperature limitation of the alloy ZA27 in an effort to develop a new functional material with high damping capacity and good elevated temperature mechanical property. The effects of addition of 5 wt pct of Si Qn the damping behaviour and elevated temperature creep resistance of alloy ZA27 were investigated. The damping capacity, as well as the relative dynamic modulus, was measured at frequency of 1,4 Hz over the 303 to 573 K. No peak phenomenon was observed for the specimens tested in the temperature range of interest. Experimental results indicated that the damping capacity of the deposited material was 2.8 times higher than that of the cast one at 305 K. The ball hardness values were used to evaluate the creep property and the creep activation energy of the deposited material is 3.9~5.7 kJ per mol higher than that of the as-cast one. The creep rate formuIation was also derived. Finally, the operative damping and creep mechanisms were discussed in the light of the data obtained from its characterization of microstructure, damping capacity and creep reslstance
关键词:
